Healthy Food & Healthy Living by Dr. Ayala

Non-caloric sweeteners on the rise: Should we be concerned?

Americans eat a lot of sugar – 15 percent of daily calories are from added sugar alone. Sugar’s high caloric price as well as its rising market cost are moving consumers and food makers to replace sugar with ever rising amounts of low-calorie sweeteners such as Equal, NutraSweet, Splenda, Sweet'N Low, Stevia and many others. Replacing sugar with no-calorie sugar substitutes potentially saves many calories, but also raises concerns about what happens when you dissociate sweetness from energy: how does non-caloric sweetness affect appetite, eating habits and weight?

And since the sugar-substitute experiment is long underway, it’s a good idea to stop and see how the trial is faring: are low caloric sweeteners helping in the obesity fight?

Food and nutrition experts met in the spring of 2011 in Washington DC to do just that in a workshop called: “Low-Calorie Sweeteners, Appetite and Weight Control: What the Science Tells Us”. The presentations of this workshop are summarized in a upcoming supplement of the Journal of Nutrition and make for some interesting reading.

Does sweetness promote overeating?

Tasting something sweet activates pleasure centers in the brain.  Do you know what else activates these neural reward pathways? Addictive drugs such as alcohol and opiates work on the same brain mechanisms. That of course doesn’t mean that drug addiction and our affection for sweet food are the same thing – but it does help explain how strong and well conserved our sweet preference is.  Loving sweet is innate and present even before birth. It probably served our species well, leading babies to crave mother’s milk and all other aged humans to seek ripe fruit.

A few interesting findings from the article about sweetness and food preference:

• Sweet taste makes pain go away: a Cochrane review showed that sweet tasting solutions reduced the reaction to pain in babies. Sweetness continues to act as an analgesic in childhood.

• We sense sweet taste through taste receptors in the mouth, but receptors are present also in our intestine and our pancreas. Stimulating these receptors leads to a cascade of physiologic reactions, including insulin and other hormone secretion, stomach emptying, appetite control and gut motility. These receptors can’t tell caloric sweeteners and non-caloric sweeteners apart -- they react to both, to a degree that isn’t completely understood. 

• Young kids prefer super sweet -- the sweeter the better. They’ll always gravitate to sweet rather than plain. Kids can also discriminate between sweet-tasting foods differing in energy content, preferring those that are more energy dense. 

• Preferring sweetness is natural, but also learned: babies and young kids exposed to sweet foods and drinks prefer sweet foods, and eat more of them. Through their experience with food kids ‘learn’ what should and shouldn’t taste sweet. Repeated exposure to sweet drinks leads to preference of sweet drinks. 

• The ready availability of sweet, highly rewarding foods, can promote overeating and weight gain. Adding sweetness (caloric or non-caloric) to foods that are not naturally sweet -- think cereal, water, yogurt or milk -- creates dietary habits of overconsumption. It’s just human nature.

The science of non-caloric sweeteners

Thanks for hanging in there up until now. I bet you’re curious to know the bottom line verdict of this workshop. Two years ago, the new Dietary Guidelines for Americans concluded that:

“The replacement of sugar-sweetened foods and beverages with sugar-free products should theoretically reduce body weight. Yet many questions remain, as epidemiologic studies show a positive link with use of nonnutritive sweeteners and BMI. Additionally, whether use of low calorie sweeteners is linked to higher intake of other calories in the diet remains a debated question.”

I’m afraid not much has changed.

The workshop concluded that the bulk of epidemiologic, observational studies, but not all of them, reported that use of low-caloric sweeteners is associated with obesity and weight gain. However, association doesn’t prove causality. Real evidence, the experts say, can only come from well-performed randomized controlled clinical trails, in which people will be assigned randomly to consume either non-caloric sweeteners for long periods of time, or serve as controls.

Until then, the large-scale non-randomized population experiment is ongoing, we’re all part of it, and I don’t think it’s going too well. I choose to be in the control group.

Dr. Ayala

Full disclosure: I’m vice president of product development for Herbal Water, where we make organic herb-infused waters that have zero calories and no sugar or artificial ingredients. I’m also a pediatrician and have been promoting good nutrition and healthy lifestyle for many years.

 

The health and weight of the (young) nation

It has been many a pediatrician’s nightmare prediction: rising obesity rates are likely to cause an increase in type 2 diabetes in teens, in much the same way these two conditions are linked in adults.

And this fear has come to pass. Type 2 diabetes, unheard of in kids just a few decades ago (it used to be called adult-onset-diabetes for just that reason!), has become unexceptional in pediatric practice.

But what we’ve seen so far seems to be just the tip of the iceberg. A new article in Pediatrics looked at a group of about 3400 nationally representative teens (aged 12-19), and found that diabetes and pre-diabetes nearly tripled in less than 10 years, jumping from 9 percent in 1999-2000 to 23 percent in 2007-2008.

The authors, led by Ashleigh May, warn that these results should be interpreted cautiously: Diabetes and pre-diabetes were diagnosed by a single fasting blood sugar test. The true prevalence of type 2 diabetes in kids is hard to know unless blood tests are done because the disease can have little or no symptoms for a very long time. The numbers do look high, and it’s going to be interesting to see if other large-population studies corroborate them.

Teens at serious cardiovascular risk

High blood sugar wasn’t the only cardiovascular risk factor facing the teens in the study. Overweight and obesity were common – 16 percent of the kids were overweight and another 18 percent were obese.

On top of that, 14 percent of kids had pre-hypertension or hypertension, 22 percent had borderline or high LDL (bad) cholesterol, and 6 percent had low HDL (good) cholesterol.

All these above mentioned risk factors were seen much more frequently among the kids with overweight and obesity, in fact, among obese teens 61 percent had at least one cardiovascular risk factor on top of their weight status, and 8 percent of the obese teens had 3 or more of the tested risk factors. But even among normal weight teens 37 percent had a cardiovascular risk factor (the most common of which was high LDL), showing that even when teens aren’t overweight they can benefit from interventions promoting a better diet and more physical activity.

A bit of good news if I may: it seems like obesity rates have leveled off and they haven’t changed much during the 9 years covered in this study. For overweight and obesity to level off at a third of the pediatric population is of little comfort, though

Diabetes in teens carries extra burden

Kids with diabetes not only have more years to accumulate the disease’s serious complications – the longer one has diabetes the more likely heart, kidney, eye, nerve and other body systems are to suffer its consequences. Type 2 diabetes is also proving to be much harder to treat in young patients according to recent studies.

It doesn’t have to be so!

I assume that the vast majority of the kids in this study had pre-diabetes – a condition that if left unattended can, and often will, develop into diabetes (the article doesn’t differentiate between diabetic and pre-diabetic teens). But pre-diabetics can reverse their metabolic state with just modest weight loss and exercise.

And for all of us, type 2 diabetes is mostly a lifestyle disease. It is really up to us to feed kids better and help them become more active so they’re not doomed to develop totally preventable disease and disability as young adults.

What to do? HBO’s excellent Weight of the Nation looks at this complex issue in depth and with compassion. If you haven’t seen it yet, I highly recommend the Children in Crisis chapter (I actually think it’s a good idea to watch the chapters out of order – I found the first installment, Consequences, to be so depressing that I have a feeling some viewers might have just given up on both the series and on dealing with obesity before that chapter was over).

As Dr. Tom Frieden, CDC director, says: The weight of the nation is not healthy. And to get it healthy, we’re all going to have to do our part.

 

Dr. Ayala

 

Study proves school nutrition standards work

School meals are far from perfectly nutritious, even after the long awaited and very welcome changes put in place earlier this year.

The good news is that under the new guidelines kids will hopefully double their fruit and veggie intake, will be served more whole grains, all milk will be low fat, and there’ll be upper limits to salt, trans-fat and calories in the school meal. The not so great reality is that kids will continue to eat lots of highly processed foods – very few schools actually cook food from scratch – and tomato paste on pizza counts as a vegetable.

But school food isn’t just the subsidized school lunch; competing with it are the foods sold in schools -- in vending machines, school stores, and a-la-carte in the cafeteria -- which make a big part of what kids actually eat while they’re in school.

The USDA administers and regulates the school lunch program, and is developing nutrition guidelines for the foods and drinks sold at schools. (The Healthy, Hunger-Free Kids Act, passed in 2010, gives the Agriculture Department authority to set health standards for all foods sold on school property — including those in vending machines). Right now, the only existing federal restriction is that foods of “minimal nutritional values”, such as candy and soda, won’t be sold in the cafeteria during meal times. That of course doesn’t mean they can’t be sold right outside the cafeteria doors.

In the meantime some states have developed their own regulations. Studying the effects of different sets of regulations and their enforcement can teach us what’s been successful – and what doesn’t work.

Vending machines with fewer calories

California was one of the first states to implement rules for vending and selling foods in schools; these rules limit the caloric content, fat and sugar in snacks, and ban soda and sweetened beverages.

A new study in the Archives of Pediatric & Adolescent Medicine compared California high school students’ daily intake to the intake of students from 14 states without any school nutrition standards. 

California kids ate fewer calories per day at school -- 170 fewer – compared to high school students in other states. California kids also consumed less fat and sugar.

Did the kids load up the ‘lost’ calories on their way home or once they got there? It doesn’t seem so. Although California students ate more of their daily calories out of school when compared to the kids from the “no rules” states, the Golden State’s students took in 158 fewer calories a day, overall.

And a reduction of 158 calories is a big deal. We gain weight very gradually, and reducing even 100 calories a day can prevent weight gain and put a dent in the obesity crisis.

Fewer calories, perhaps no better nutrition 

California students ate fewer calories from fat and sugar, but the study found that their intake of nutrients such as vitamins and minerals was unchanged compared to the students from the other states. 

The authors suggest that the reason lies if the food laws themselves: the laws limit sugar fat and salt, they don’t require whole grains, fruits or vegetables. Replacing full fat chips with baked low-salt ones can only do so much.

Providing truly healthy substitutes is obviously the next step, but since obesity – too many calories -- and the abundance of sugar, fat and salt in kids’ diets are the main nutrition problem facing us, I’d conclude that California kids seem to enjoy better nutrition according this study.

Does public policy impact kids’ health?

While there are plenty of studies that show policies have a positive impact on kids’ eating habits, there are definitely studies that show that they don’t. I shared a recent study that showed that in schools that banned only soda, kids bought the other vended sugary beverages instead.  In schools that banned all sugary drinks kids indeed consumed fewer sugary drinks at school, but their consumption did not decrease overall; kids were able to find sugary drinks out of school, and filled the sugar gap before and after school. In other words, school vending policies only changed the school environment, and didn’t seem to be enough to change kids’ access and behavior overall.

I’d argue that even if the regulations don’t have the immediate nutrition-improving outcome we’d hoped for, it’s still imperative to apply nutrition rules for educational reasons. It’s impossible to advocate for safe driving while holding a cellphone with one hand and the wheel with the other.

School should have a central role in nutrition education, and you can’t teach healthy nutrition while benefiting from the sale of junk food within school walls.

Kids spend half their waking hours in school and consume much of their daily calories while on campus. Changing school food should be a critical part of the effort to combat obesity.

Dr. Ayala

 

Put those fruits and veggies a little closer

Much of our eating is mindless and automatic. That’s why environmental changes can lead us to overeat. Many argue that what’s at the root of the obesity epidemic is the transformation in our environment, which gradually changed into an obesity-promoting one.

Proximity and convenience affect food choices. Food sellers know that the closest, easiest to grab, and most noticeable food items will sell more, that’s why they place the products that they want you to buy on an eye-level shelf, near the checkout and in an open case. Previous studies have shown that when candy is placed closer and is in a clear rather than an opaque bowl, people eat more of it.

Could proximity and visibility promote good-for-you foods just as well?

Gregory Privitera and Heather Creary tested how distance and visibility affect apple and carrot consumption. Their new study appears in the Environment and Behavior Journal.

The 96 healthy students in the study were not aware that eating behavior was the purpose of the experiment, and were assigned randomly to have a bowl of the fruit or the veggie in one of these four settings:

• Within arm’s reach and in a clear bowl
• Within arm’s reach and in an opaque closed bowl
• On a table about 2 yards away in a clear bowl
• On a table about 2 yards away in an opaque closed bowl

The students watched the researcher take the food out of a sealed bag (this was done to ensure the participants knew the food’s fresh and good to eat), and the researcher then excused himself for 10 minutes, with a cover story of “I’ll be right back with some questionnaires”, and an invitation to munch on the carrots or apples.

Within arm’s reach

Leaving the apples and the carrots close, within arm’s reach of where the student sat, increased intake significantly. The transparent bowl trick worked only with apples; carrot intake wasn’t significantly increased when the bowl showed though. The researchers suggest an explanation:

“apple slices may be more visually appealing than carrots in that seeing sweet-tasting apple slices (vs. bitter-tasting carrots) induces a stronger wanting to consume those foods.”

I’m here to defend the meager carrot: carrots are generally not bitter! I wonder where the researchers got their veggies, or when they last tasted a good carrot. Carrots actually have high sugar content, and are very tasty! They’re pretty, too.

Anyway, I suppose most moms knew this intuitively, but here’s some experimental proof showing that making fruits and veggies readily available can get us closer to the minimum recommended 5-a-day.

Another thing that caught my eye in this study is the background information on the study group. The students were about 19 years of age, and their average body mass index (BMI) was about 27. A BMI of above 25 puts a person in the overweight range. The study sample is a small one, and quite random, but what we see again and again is that even among young students, being overweight has become the norm. Every year of being overweight adds to the risk of chronic diseases such as type 2 diabetes and heart disease, and that’s why the overweight and obesity epidemic among kids and young people is especially worrisome.

Eating more fruits and veggies is important to health, as well as for healthy weight maintenance; so let’s think up some clever fruit and veggie placements!

Dr. Ayala

 

Preschoolers suffering nature and exercise deficits

A happy day is one in which some time is spent outdoors.

Dog owners take their dogs out daily, and pediatricians suggest we extend the same kindness to our kids.

No, seriously, kids need the outdoors quite critically. Outdoors translates to physical activity and fitness, and the more time kids spend outdoors the less likely they are to become obese. Kids don’t exercise in gyms; they have bursts of intense, vigorous, heart racing activity while playing in a large open space, when they’re chasing a friend or a squirrel, or repeatedly going up and down a slide. Playing outdoors also helps kids’ development and growth and does wonders to their vision, coordination, vitamin D levels and mood!

Experts say that free play — especially outdoors — is crucial to a kid's health, but chances to play outside have been on the decline over the past few decades. Busy lives, over anxiety about safety, screen based entertainment and lack of awareness are keeping kids indoors.

Not enough outdoors time

A new study in the Archives of Pediatrics & Adolescent Medicine looked at the frequency at which parents took their kids to play outside. The authors, led by Pooja Tandon, used a nationally representative sample of about 9,000 4-year-olds, whose parents were asked how often they took their kid out to play. 

They found that about half of the preschoolers were taken out by their parents daily.

Is another caregiver taking these kids out? Possibly — daycares are supposed to take kids out. But even among the 20 percent of children in the study who didn’t attend any day care or preschool at all, only 58 percent went outside daily with mom or dad.

Is safety the issue?  

An important barrier to spending time outdoors could be perceived or actual concern for safety. This study found that the vast majority of parents thought that their neighborhood was either very safe (58 percent) or fairly safe (35 percent), with just 5 percent assessing their area as fairly unsafe and only 2 percent as very unsafe. So dangerous neighborhoods were not the issue.

Has TV replaced playing outdoors? The researchers found that the 4-year-olds in the study spent almost 4 hours a day in front of a screen — which is a lot, and almost double the (generous) American Academy of Pediatrics’ suggested upper limit — nevertheless, screen time wasn’t correlated with how often parents took their kids out to play.

There was also no correlation with household income or mom’s marital status. 

There were, however, two interesting variables that increased the odds of getting regular fresh air: boys were taken out more often than girls, and moms who exercised regularly were more likely to the take their kids out.

It seems like active parents raise their kids to be more active, and perhaps the known statistic that boys are generally more active than girls can be partly explained by the fact that boys are given more opportunities for activity. 

Get outside!

Being active starts at home and with the parents.

Barring dangerous weather, kids — and adults — I do believe, will do themselves some good by spending some time outdoors every day. Regardless of what happened at day care or school, parents should encourage kids to go out, run around, look at trees and birds, meet some insects, get dirty and come back tired. I can’t think of a better way to take a break from work, media and chores than to leave them all behind and go out with the kids. Soon enough these young kids will be able to enjoy the outdoors without adult supervision, and if you’ve collected some great outdoor memories you’ll be rewarded with outdoor enthusiasts for life.

Dr. Ayala

“Sunshine is delicious, rain is refreshing, wind braces us up, snow is exhilarating; there is really no such thing as bad weather, only different kinds of good weather.” ~John Ruskin

 

Can we blame our habits for making us fat?

We’d like to think we’re free to make choices about our everyday life.

But studies show that almost half of the actions people take each day aren’t actually a result of decisions – they’re driven by habit alone.

Habits are so strong and so ingrained that they override many other thought processes. It seems like our human brain, trying to save on energy, goes into autopilot for every process it can use old routines for, and will fight any proposed change. The positive side of habit is that once you’ve mastered dressing up in the morning and backing out of your garage, your mind can wander free while you’re performing a rather complicated task. The negatives are quite clear to anyone trying to lose weight or stop smoking.

Charles Duhigg’s "The Power of Habit" is a fascinating exploration of the research of habits, and is packed with absorbing stories about how habits influence every aspect of our lives – the way we shop, listen to music, drive, and of course eat is driven mostly by habit. Understanding habits is the key to creating change.

The habit loop

A habit is a three-step loop, written in our brain’s pathways. First comes a cue: a trigger that tells our brain to go into the automatic mode of the habit. Then comes the routine, which is the physical, emotional or mental action we take. What follows is the reward: the prize at the end of the routine is what reminds our brain why this habit is worth keeping. When a habit is fully formed the reward’s rush of excitement appears well before it actually happens – brain scans show that we expect the reward and get excited as soon as the cue appears, and this anticipation creates cravings.

Food habits start innocently: Feeling tired or bored an hour after lunch can become a cue to walk to the vending machine and select a high calorie snack that hits all the right spots and gives you the instant reward of yumminess and energy. After repeating this routine several times it becomes habit, and your brain craves to finish the loop whenever the faintest prompt shows up. 

Watching TV acts as a cue for many people to munch: the cue is the TV or the couch, the routine is going through a bowl of chips, and the reward is that physical sensation of this delightful combo experience. The loop becomes so automatic, that watching TV without a bowl of munchies makes you feel robbed (and in case you forget it there’s always an ad to remind you that watching is better with eating).

Advertisers are well aware of the psychology of habit, and if you examine carefully, many ads and marketing campaigns build a habit loop in which they tie a certain cue – be it a place, an emotion, a time of day, a thought or a situation – to the action of consuming their product and feeling its reward. Duhigg uses McDonald’s as an example of habit building strategy:

“Every McDonald’s looks the same – the company deliberately tries to standardize stores’ architecture and what employees say to customers, so everything is a consistent cue to trigger eating routines. The foods at some chains are specifically engineered to deliver immediate rewards – the fries, for instance, are designed to begin disintegrating the moment they hit your tongue, in order to deliver a hit of salt and grease as fast as possible, causing your pleasure centers to light up and your brain to lock in the pattern. All the better for tightening the habit loop.”

Keystone habits

Some habits are more important than others, because they spill over to other parts of life, causing a ripple effect. These habits are called keystone habits and identifying them can often trigger widespread change.

Take exercise: Studies show that introducing exercise – even infrequently – changes other daily routines. Unknowingly, people who start to exercise start eating better, are less stressed, and become more productive at work. Duhigg lists eating dinner as a family as a keystone habit, which seems to go with better homework skills, higher grades, better self-control and more confidence.

I’d argue that sugary drinks are a keystone habit that initiates an array of associated poor nutrition habits. That’s one of the reasons most serious diet programs target the sugary drink habit first – winning the soda habit change leads to several other wins that follow.

Is habit destiny?

Once a fresh sheet of paper has been folded it will tend to fold into the same crease, and once water carved a path in the soft soil water will naturally flow in the same route, but our habits are malleable, and as Duhigg concludes:

"Once you know a habit exists, you have the responsibility to change it...others have done so...That, in some ways, is the point of this book...how we eat and sleep and talk to our kids, how we unthinkingly spend our time, attention and money — those are habits that we know exist. And once you understand that habits can change, you have the freedom and the responsibility to remake them. Once you understand that habits can be rebuilt, the power of habit becomes easier to grasp and the only option left is to get to work."

Changing habits is very hard work, and thinking about the power of established habit should remind us to be aware of habit acquisition, especially as parents.

We can do our kids a favor by helping them acquire good habits – habits that ensure that their automatic, default routines are healthy and beneficial. If kids brush their teeth every night before bedtime, get used to healthy eating habits, learn how to cook and are active when young they’re likely to continue doing these things throughout life.

We should also do our best to help them avoid habits that will be difficult to fight later on. Highly processed, densely caloric salty sweet and fatty foods are addictive and habit forming – ads make them even more so. Eating while multitasking, constant snacking and eating in the back seat of a car are learned routines that will not serve them well.

Dr. Ayala

“It is easier to prevent bad habits than to break them” ~Benjamin Franklin 

Reposted as part of Food Renegade's Fight back Fridays. 

Flat Belly Tip: Eat More Fiber

Not all body fat is created equal.  Some people accumulate fat predominantly in the belly, while in others fat deposits are spread all around, and it does matter, because belly fat presents a higher risk for chronic diseases.  Think of belly fat as a big, active endocrine gland secreting risky substances — abdominal or visceral fat is especially active metabolically and plays a part in insulin resistance and diabetes, lipid abnormalities, hypertension and cardiovascular disease. 

And here’s another piece of worrying news: The majority of Americans are now overweight or obese, and the extra padding we’ve added as a population has accumulated preferentially in the worst location for our health — our belly — and even people with normal weight seem to be getting wider waistlines.

Why are bellies getting disproportionately bigger? Some ethnic groups — such as Asians, Indians and Hispanics — have a higher tendency to accumulate abdominal fat. Other factors suggested to affect belly fat buildup include lack of exercise.

But does our diet affect where we deposit our fat stores?  Does the kind of food we eat determine body shape?

Lifestyle and belly fat

Several studies suggest that sugary drinks and fructose increase fat accumulation in the worst possible locations of our anatomy.

A new study in the journal Obesity followed 1,114 people over 5 years, looking to see if lifestyle factors directed fat preferentially to the belly.

The study population included 339 African Americans (African Americans tend to have lower belly fat than whites or Hispanics) and 775 Hispanic Americans, aged 18-81 years.   Participants were asked about their dietary and exercise habits, weight and height were measured at baseline and follow-up visits, and belly fat was measured with an abdominal CT scan.  A CT scan is a rather invasive way to measure belly fat, but a very accurate one.

Of all the foods and nutrients considered in the study one single nutrient was most significantly associated with belly fat: Fiber.  For every 10 grams of soluble fiber eaten per day, belly fat was reduced by about 4 percent after 5 years -- irrespective of total weight or BMI. 

Other studies have shown that reduced fiber diets are associated with weight gain, but this study actually showed that soluble fiber makes fat “choose” a depot that’s healthier for us — if you overeat, but eat more soluble fiber, the fat will go under the skin, rather than into the belly.

Oh, and here’s one more important finding: Vigorous exercise was also associated with less belly fat. 

Fiber: soluble, insoluble, and where to find it

Dietary fiber is a part of plant food that we humans cannot digest, but it nevertheless has many health benefits.

Soluble fiber is fermented by bacteria in the gut and has physiologically active byproducts; insoluble fiber is metabolically inactive, and just absorbs water and creates bulk as it moves through the gut, thus speeding food’s passage in the gut and preventing constipation.

Both soluble and insoluble fiber may help in making us feel full on less food, because they add to food bulk while adding no calories.  Soluble fiber has shown promise in lowering LDL (bad) cholesterol, regulating blood sugar and prevention of heart disease.  Insoluble fiber aids regular bowel movement.

Good sources for soluble fiber include fruits such as apples, bananas, plums, and berries, vegetables such as broccoli and carrots, sweet potatoes and onions, legumes such as soy, peas and other beans, and grains such as oats and barley.

Good sources of insoluble fiber include whole grain foods, bran, nuts and seeds, vegetables such as celery and zucchini, and the skins of many fruits and veggies.

Most Americans get only about 15 grams of fiber per day in their diet, which is half the minimum 25-30 grams recommended.

What about fiber supplements and foods with fiber added to them? It’s unclear if added fiber provides the benefits of naturally occurring fiber and the benefits of supplements have not been studied as extensively as those of dietary fibers – the food plant as a whole is usually more than the sum of its known parts.

Fiber for a flat belly

All fruits, veggies whole grains and nuts contribute fiber to our diet.  I don’t participate in the fiber wars, and wouldn’t favor one fruit over another for its fiber quantity or quality.  If you eat your fruits and veggies you’ll get plenty of fiber – but do try to leave the peel on where appropriate.

Eating fruits and veggies reduces the risk of obesity, but this new study suggests that eating them also enables us to direct where were we deposit our fat even if we do gain weight — dietary fiber may funnel that fat to a more favorable storage area.

Dr. Ayala 

 

Moms oversharing their kids’ most personal stories

The mommysphere was abuzz over Dara-Lynn Weiss's Vogue article that detailed her effort to get her 7-year-old daughter to lose weight.

Criticism of Weiss spread like wildfire, especially after Katie J. M. Baker posted her scorn in Jezebel and described Weiss’ self-reported intense regimen of calorie restriction and public shaming as “abrasive, often irrational weight-loss strategies” and accused Weiss of projecting her hatred of her own body onto her child, and of writing the “worst Vogue article ever”.

Was Weiss wrong to put her daughter on a diet? Was the diet regimen inappropriate? Was its message misguided? Is being tough on your kid a parenting mistake?

There are situations in which action needs to be taken to prevent kids from further weight gain, and it’s definitely a parent’s job to educate kids about healthy eating and active lifestyle, and to provide for healthy food. There’s more than one way to obesity prevention and treatment in kids, and the discussion about what to do when a kid is diagnosed with overweight or obesity is an important one.

But here’s why I’m absolutely appalled by Dara-Lynn Weiss's piece: the Vogue article not only gave the child’s full name, it also displayed her photos.

A few days after witnessing the media party around the 7-year-old-on-a-diet, I read Elizabeth Weil’s Puberty Before Age 10: A New ‘Normal’? in the New York Times. This article opens with a story told by another mother, Tracee Sioux, whose daughter started growing pubic hair at the age of 6. Again, full name of the child, hometown and picture all included.

Outing kids

Reality TV seems to have dampened our instinct for privacy.

Adults willing to share tears and fears and humiliation with strangers are one thing, but dragging your kids exposed into the village square is an entirely different story.

Could anyone really imagine that a girl could benefit from the world knowing when her breasts budded?

So here’s an easy trick for moms with oversharing tendencies: Ask yourself this: if someone else revealed the information about your kid, would you feel comfortable? If your kid wanted to expose the information on the Internet, would you advise him to go ahead?

I’m sure most parents would be outraged if their kid's weight struggles, breast budding or pubic hair appearance were exposed by a reporter or a friend. They’d sue them!

Why did these moms do it? Weiss’ diet might have been designed to help her kid. Sioux might be thinking that she has an important story to tell.

But revealing the names and images served only mom’s interest – and was done for publicity and financial gain. Apparently, Weiss scored a book contract with Random House following her article. Sioux got to plug her “No Craptastic Ingredients” cosmetic line in the Times article as the solution to early puberty.

Every parent will make mistakes. I believe that kids are pretty resilient, and usually turn out fine despite the fact that perfect parents don’t exist. Our kids might be angry with us over what they see as our wrongdoing, but will forgive us – because most kids realize their parents do the best they can, and mean well.

I really can’t see exposing your kids’ private life for financial or any other gain as an act done in the kids’ best interest.

Dr. Ayala

 

Do nutrition labels confuse you?

 

Nutritional labels have been around for well over a decade, and the familiar panel — which provides some key nutrition information, an ingredient list and nutrition declarations — enables more informed food decisions.

Do people make good use of the information? The first step is for people to bother looking at it -- and they do. Women more than men, health conscious and exercise enthusiasts more than couch potatoes, but most people report they do consult with the label, at least when they’re buying a product for the first time. A recent review of 120 studies of nutrition label usage in Public Health Nutrition finds that 75% of Americans check the label.

Eyeing the label is a good start, but do consumers get what they need from it?

A recent paper in Nutrition Reviews found that of the 60 percent of consumers who said they use the Nutrition Facts Panel, only a quarter found it easy to use. The calorie information on the Nutritional Facts Panel gets a glance from 75 percent of consumers, but most consumers cannot put the calorie count in context since they have no idea how many calories they should consume, and about half of the people overestimate their suggested daily caloric intake. The percent daily values, typically located above the actual ingredients, were either ignored or poorly understood by most surveyed.

A ‘D’ in label comprehension

A new study in the journal Appetite studied 120 young Israeli adults’ understanding of the various parts of the nutrition label. The study was performed in a travellers’ immunization clinic, so it’s by no means a representative sample of the population, but rather a group of highly schooled, mid to upper socio-economic class individuals.

People were presented with several common food products, and were asked about their attention to and understanding of the nutrition facts on the label.

Most of the people (almost 80 percent) reported that they looked at nutrition labels when selecting foods.

But when given a label comprehension evaluation, the average score was a ‘D’ – 60 percent correct answers.

The nutritional table was understood much better than the ingredient list or the nutrition declaration information. For instance, when asked about red “Bamba”, most participants replied it did not contain food coloring, although the ingredient list says it does -- Bamba uses natural food color. (Bamba, a corn peanut snack, is perhaps the strongest food brand in Israel. It’s perceived almost as a weaning food, and is said to be the third word an Israeli baby attains – right after “mom” and “dad”.) The nutrition declaration piece, with its “without”, “contains no” and “less” assertions was least understood. When a bottle of canola oil declares it contains “no cholesterol” does it mean there’s naturally no cholesterol, or that this manufacturer kindly removed the cholesterol for added nutrition value?

Figuring out food labels

The nutritional label is an important tool for promoting healthy eating. Reading the label helps consumers decide if, and how much, of that packaged food they should eat.

Some of the nutrition confusion can be solved by nutrition education – of which there currently is very little. Not all people know that ingredient lists, by law, have to list ingredients by their relative amount in the product, from high to low, so fruit as the first ingredient is very different from fruit at no. 5, and that added sugar comes has so many different names. The people in the Israeli study thought they understood the label much better than they actually did – they didn’t know they didn’t know – and that overconfidence hinders further learning.

The nutrition label could also be more consumer friendly. Most studies suggest that readability (larger fonts please!) and clarity could be much improved. There are many suggested simple, visual symbols such as the traffic light symbol, that attempt to give a nutrition-in-a-nutshell view on the front of the panel. Each system has its supporters and detractors. Recently, the Institute of Medicine advocated that the front of the package panel display only four nutrition facts: calories, saturated and trans fat, sodium and sugars. It recommends that the FDA develop a point system -- much like the energy star® program used for assessing electronics’ energy efficiency – which takes into account just saturated and trans fats, sodium, and added sugars, since these nutrients pose the most pressing diet-related health concerns.

To increase the mix-up, manufacturers introduce some more confusion in an effort to better market their product. The declaration “no cholesterol” on a vegetable oil is redundant – no vegetable oil has any cholesterol, as cholesterol is present only in animal derived foods. Likewise, package health claims promising “immunity” “antioxidants” "heart-health" “strong bones” and “lower cholesterol” don’t mean the food is healthy.  They practically don’t mean a thing.

So how to read the label? For an FDA tutorial on how to read the Nutrition Facts label go here, and I’d love to hear your personal approach.

Dr. Ayala

 

Can fruits and veggies make your skin glow?

I used to chuckle when I heard moms urge their daughters to eat tomatoes for rosy cheeks. Old wives' tale, so, I thought, and by that logic would I turn greener with kale? I was a little less sure of my dismissiveness when my own palms turned an orangey tint when I went heavy on my carrots, and was totally humbled when I met my first pink flamingoes.

Beauty from the garden’s bounty 

A new study in the scientific journal PLoS ONE followed 35 students for 6 weeks looking at how fruit and veggie intake affects skin tone, as measured by a spectrophotometer (an instrument that measures the spectrum and photometric intensity of each wavelength present, and in this case of visible light). 

The researchers, led by Ross Whitehead, found that measured skin tone correlated with reported changes in the diet: eating more fruits and veggies increased skin redness and yellowness, and these skin color changes where achieved with a relatively modest increase of fruit and veggie intake – adding about 4 servings did the trick.

In a second part of the study, the researchers asked 24 students to rank face’s health appearance and attractiveness when these faces were manipulated to take on the hue change seen under low fruit and veggie diet as opposed to a fruit and veggie rich one.  The experiments showed that the faces with the skin color associated with high fruits and veggie intake were perceived as more appealing and vibrant.

Carotenoids and blood perfusion

This study, and others before it, show that we prefer rosy, slightly flushed, lightly yellow-toned skin -- perhaps because it sends a signal of healthfulness -- and pigments from the fruit and vegetables in our diet seem to impart just the right tone to our complexion.

Fruit and veggie pigments, such as lycopene and carotenoids, make their way into the skin and change its hue. Fruits and veggies may also change skin’s blood perfusion. 

Skeptical of this small study’s results? We are what we eat, and food affects health in a profound way. There are many reasons to eat your veggies, but if you find the beauty-from-a-tomato argument effective, I’d consider this study support to use it as needed.

Dr. Ayala

Hot peppers, brown fat and weight loss

A new chili pepper was recently crowned the hottest of the hot. It’s called the Trinidad Moruga Scorpion and has a measured spiciness of 2,000,000 Scoville heat units, which brings it to the level of law enforcement grade pepper spray.  Care for a bite?

Hot peppers and weight loss 

Hot peppers have many culinary and nutritional benefits, and have also been used for topical pain relief. One of the interesting research areas of hot chili peppers is their alleged capacity to aid in weight loss.

A few studies showed that eating good amounts of hot peppers might increase energy production as heat temporarily in rats and in people. Increasing energy expenditure’s a good thing – we’d love to burn extra calories without hard work.

The active ingredient in hot peppers is capsaicin. Capsaicin also gives peppers their pungency, which limits the amounts people can comfortably eat without hitting the ceiling.

Brown fat and spicy peppers

Hot pepper’s capsaicin weight loss effect on rats and mice can be explained by the rodents’ elevated temperature after ingestion. Rodents’ brown fat, which usually burns energy and creates heat during cold exposure, showed elevated activity and temperature after eating capsaicin.

Scientists once thought that brown fat was only present in babies. We now know that brown fat can also be detected in about 50 percent of healthy adults, that the human body is capable of creating new brown fat cells throughout life, and that the amount of brown fat in the body may affect the likelihood of obesity.

Might brown fat activity explain hot peppers’ metabolic effect on humans too? 

A new study published in the American Journal of Clinical Nutrition started by measuring the brown fat activity of 18 healthy young men. The men underwent a special PET scan exposed to a temperature of 66 °F, while intermittently placing their feet on a block of ice. Ten of the 18 men had brown fat activity, and 8 had no such activity.

Next, the researchers exposed both the men with brown fat and the men without brown fat to capsinoids. Capsinoids are similar to capsaicin in formula, but aren’t that spicy. They come from a unique variety of non-spicy chili peppers, CH-19 Sweet, and have been shown to have effects similar to capsaicin. The energy expenditure of both groups was similar before ingesting the capsinoids. The brown fat positive group’s energy expenditure increased after capsinoids ingestion, but not after ingesting placebo. On the other hand, the men who had no detectable brown fat showed no increase in energy expenditure after capsinoids ingestion or after ingesting placebo.

How much increase in energy burning are we talking about? The brown fat endowed's extra energy burn in the hour after ingesting their hot pepper analog was an average of about 15 kilojoule an hour.

To put this number in more understandable terms, 15 kilojoules are about 4 of our familiar calories. All this hot pepper earned eaters an extra piece of chewing gum.

Spiciness is a nice add-on

Hot pepper weight-loss research, though exciting, brings one down to earth regarding the possibility of a magic remedy soon replacing the true but unpleasant advice of “eat fewer calories and exercise more”. Under the best of circumstances, adding palatable level of spiciness will result in very modest weight loss, and we’re not at all sure about the long-term effects of hot peppers, as people may adapt to the effects of capsaicin over time.

If you enjoy spicy food, look at hot pepper as a nice add-on. It has shown some activity, similar to that of green tea and caffeine. But by all means don’t see hot sauce as an excuse to eat more, or hope that it can help you lose weight without decreasing overall caloric intake.

I happen to love spicy food, and tiny amounts of hot pepper flakes make it into many of the dishes I cook, but I’ve come to realize that what I perceive as tingling pleasure, others feel as pain and embarrassment, so I serve the hot sauce on the side.

Dr. Ayala

reposted as Food Renegade's Fight Back Friday.

Diet Soda and Metabolic Syndrome Linked in New Study

We’ve developed a national sweet tooth problem. Enjoying sweet foods is the most natural, inborn tendency – it used to get us excited about mother’s milk and ripe fruit -- but our level of added sugar consumption has reached such absurd heights that it’s clear that these mountains sugar are fueling the obesity epidemic.

To our alleged rescue came non-caloric sweeteners, offering the same intense sweetness without the caloric price tag.

Alas, diet drinks may not assist with weight loss. A few long-term studies surprisingly showed a dose-response correlation between consuming diet drinks and the development of obesity.

What was even more alarming was the emergence of studies showing a connection between the consumption of diet drinks and chronic disease: diet drinks were linked with the metabolic syndrome* and type 2 diabetes, and a recent study published in the Journal of General Internal Medicine showed that people who drink diet soft drinks on a daily basis may be at increased risk of stroke, heart attack, and vascular death.

The study of nutrition is a very tricky thing, as people don’t eat at researchers’ will, and the effects of many lifestyle choices – not limited to food – over a lifetime affect the measured health outcome. That’s why a good study looking at nutrition and heart health, for instance, controls for obvious confounders such as obesity, smoking, exercise and lipid profile.

The question always remains: Is it possible that the metabolic and heart problems experienced by diet soda drinkers come from some other behavior they share, one that has nothing to do with diet soda? Specifically, could diet soda drinkers have a tendency for a less healthy diet, which is the real (and already known) cause for the increased risk of disease observed?

Do those eating a less healthy diet prefer diet soda?

A new study, published online ahead of press in the American Journal of Clinical Nutrition tries to tease out the specific role that diet beverages play on metabolic health when the general healthfulness of the diet is considered at the same time.

The researchers, led by Kiyah Duffey, looked at the data of more than 4000 young adults, who were followed for 20 years for signs of heart disease, and analysis showed that their dietary practice can be broadly defined as fitting a “Prudent Diet” – emphasizing more fish, fruit, nuts and whole grains -- and “Western Diet” – highlighting meat, poultry, fast foods, refined grains, snacks and sugar sweetened drinks. Diet beverages consumption was considered separately, and the study population was classified as  “Consumers” vs. “Nonconsumers”. The study looked for development of the components of the metabolic syndrome: abdominal obesity (measured by weight circumference), elevated blood glucose, high blood pressure and high cholesterol.

Here are the main findings:

• People who ate a Prudent diet had a lower incidence of the metabolic syndrome and each of its components, compared with those who eat a Western diet.
• People who didn’t drink diet beverages (Non-consumers) had 19% lower risk of the metabolic syndrome compared with those who drank diet beverages, although the effect was not on all components of the metabolic syndrome: being a non-consumer lowered the risk of abdominal obesity the most.
• People on a Prudent diet were more likely to consume diet beverages than people on a Western diet; in other words, drinking diet soda is mainly a habit of those eating healthier diets.
• Eating a Prudent diet and not consuming diet drinks put people at the lowest risk.
• The combination of a Western diet and diet drinks put people at the highest risk for cardiometabolic outcomes.

So at least by the findings of this study, diet beverages aren’t the typical drink paired with a Western diet -- quite the opposite -- and they're associated with greater risk independently of diet quality.

Why would diet drinks lead to obesity?

The authors conclude that both dietary pattern and diet beverage intake are independently associated with the development of the metabolic syndrome and the development of abdominal obesity.

On the other hand, the study suggests that being a consumer of diet beverages in the context of a Western diet increases the risk of a metabolic outcome even more, so it very well may be that there’s an interaction between these two things.

This study didn’t go into proposed mechanisms that may explain how diet beverages might affect obesity or metabolic outcomes. Artificially sweetened beverages may habituate our taste receptors to prefer intense sweetness, leading us to reject less-sweet foods (such as veggies and fruit) and seek intensely sweetened foods. Diet drinks may also trick our hormonal and neurobehavioral pathways –- sweetness signifies to our body that energy and nutritious food are on the way, enacting a cascade of reactions, yet with diet drinks no calories are actually consumed. The outcome of this disconnect isn’t yet clear.

I’d still pick a diet drink over a full calorie one, but is seems like the more we study diet drinks the more we realize that they’re not an effective way to improve heart and metabolic health, or even lose weight.

Dr. Ayala

Full disclosure: I’m vice president of product development for Herbal Water, where we make organic herb-infused waters that have zero calories and no sugar or artificial ingredients. I’m also a pediatrician and have been promoting good nutrition and healthy lifestyle for many years.

*The metabolic syndrome is a group of risk factors including abdominal obesity, high blood pressure, elevated triglycerides, low levels of high-density lipoprotein (HDL or “good”) cholesterol and high fasting glucose levels. The presence of three or more of the factors increases a person’s risk of developing diabetes and cardiovascular disease. The metabolic syndrome has become increasingly common in the United States. It is estimated that over 50 million Americans have it. 

 

 

Kids aren’t getting enough sleep (and they never have)

Sleep’s a mysterious thing. We’re not sure what sleep is or why we need it, but we do know sleep is critical to our health and wellbeing. Lack of sleep has been associated with pretty much all that ails humans, and recently it has been also blamed for rising obesity rates.

Parents loose sleep worrying about sleep. Most parents believe their kids don’t get enough of it. We blame it on overscheduling, iPads, YouTube or our busy state of mind, but whatever it is, sleep’s always insufficient.

Sleep concerns are nothing new

A new study in the March issue of the journal Pediatrics finds concerns over kids’ sleep from the early 1900s were much similar to our concerns today. The researchers, led by Lisa Anne Matricciani, tracked more than a century’s worth of advice in more than 200 articles regarding children’s sleep, and compared it to data on how much kids actually slept over the years.

Kids always slept less that what health professionals thought they should -- about 37 minutes less than recommendations.

With the passing century sleep recommendations have also shrunk by a rate of about 0.71 minutes per year.

Our kids are indeed sleeping less: Sleep has declined about 0.73 minutes per year in the past century. That amounts to our kids slumbering about 20 minutes less than we did, and 40 minutes less than their grandparents. 

“Modern Living” robs kids’ dreams

Our great grandparents shared our perception of life going faster and faster, and a British Medical Journal editorial from 1894, titled “Sleeplessness”, cited in the article, states “The hurry and excitement of modern life is quite correctly held to be responsible for much of the insomnia of which we hear.” 

The novel preoccupation of the day has always been charged with keeping kids away from shuteye: first it was books, then the radio, and later TV, the Internet and social media.

How much sleep do kids need?

Despite finding 35 sets of recommendations about optimal sleep duration, the study discovers that the sleep need of kids remains a big unknown. Recommendations were based largely on opinions, which were based on, well, nothing really.  We have no scientific clue how much sleep kids need.

But in case you’re curious about current recommendations take a look here; these, too, I assume are based on observations and very little evidence. If your kid is tired and cranky, he’s not getting enough sleep. 

The kids are all right 

There was something comforting about reading this research. It suggests we’re just a link in a generational chain of worrying parents.

When my kids ask why I worry about them so much I say it’s mom’s job to worry. I guess it used to served our species well to be cautious and protective of our young. 

We may long for bygone, simpler times, but the kids never slept enough, whatever that enough might be, and nevertheless, they’re probably going to turn out just fine. 

Dr. Ayala

 

Halftime in the school cafeteria

Last month Michelle Obama and Agriculture Secretary Tom Vilsack announced some very welcome and long awaited changes to the government subsidized school meals. These are the first changes made in the program -- which feeds 32 million kids each day – in 15 years. Under the new guidelines kids will be doubling their fruit and veggie intake, will be eating more whole grains, all milk will be low fat, and there’ll be upper limits to salt, trans-fat and calories in the school meal.

Yes, the program is far from perfect, kids will continue to eat lots of highly processed foods – very few schools actually cook food from scratch – and tomato paste on pizza counts as a vegetable. But it’s a laudable change in the right direction, and considering the mighty fight the food industry wages against any proposed change, and the fact that the new rules will add 3.2 billion to the yearly cost of the program it’s reason for a mini celebration.

The next critical change is yet to come 

Competing with the subsidized school lunch are the foods sold in schools, which make a big part of what kids actually eat while they’re in school. These are foods and beverages sold in the cafeteria or in a school store, from a vending machine or in fundraising events. The lunch money parents give their kids may very well be spent on these offerings rather than on the school lunch.

Kids love the vending machines and the school stores, but that’s not the only reason these outlets exist. Schools depend on the revenues that vendors bring in to fund much-needed programs. This creates an unusual and worrying conflict of interest.

The USDA administers and regulates the school lunch program, and is developing nutrition guidelines for the foods and drinks available at schools. (The Healthy, Hunger-Free Kids Act, passed in 2010, gives the Agriculture Department authority to set health standards for all foods sold on school property — including those in vending machines). Right now, the only existing federal restriction is that foods of “minimal nutritional values”, such as candy and soda, won’t be sold in the cafeteria during meal times. That of course doesn’t mean they can’t be sold right outside the cafeteria doors.

Vending junk 

A new study published in the Archives of Pediatrics & Adolescent Medicine showed that even in elementary school half of the students could buy potato chips, ice cream or similar snacks from vending machines and at snack bars during school.

Other studies show that a la carte foods sold in the cafeteria are common in all school levels. Vending machines are available in 87 percent of middle schools and virtually all high schools. Forty percent of kids consume competitive foods on any given day, eating 280 calories daily in mostly junk food (the most commonly consumed competitive foods are desserts, snacks and sweetened beverages.

The new age of vending

Getting rid of the vending machines is perhaps a fancy aspiration and a non-starter, especially during tight budget times.

Instead, states and schools have put in place policies guiding the nutritional content in schools’ vending machines, and now offer healthier vending options.  Several vending companies specialize in healthy vending. 

But the neatest idea I’ve seen yet is the LiVe vending machine Intermountain Healthcare installed at Rose Park Elementary School in Salt Lake City. The talking machine will make its rounds in Utah schools spending a few weeks at each. 

 

I want one of these in my kids’ school!

Let’s hope the upcoming USDA regulations for competitive foods in schools will be sensible and have teeth. 

Dr. Ayala

 

Reposted as part of Food Renegade's Fight Back Fridays.

Study shows liquid calories trick body and mind to overeat

A calorie’s a calorie, isn't it?  Well, accumulating evidence shows that our body has a hard time registering calories from beverages in the tally towards satiety; unfortunately, these beverage's calories still count in our energy balance.  That’s why the extra calories in beverages are just extra—much like items that didn’t go into the budget, but will nevertheless have to be paid for.

There are numerous studies to prove this point; here are just a few:

Nutritionist Barbara Rolls from Penn State served women water, diet soda, regular soda, orange juice, milk or no drink before lunch. Those given caloric beverages consumed about 100 calories more than those given diet soda, water or no beverage at the meal, without significantly affecting satiety ratings.

In the cute jellybean study, researchers gave men and women 450 calories a day of either soda or jellybeans for a month, then switched them for the next month and kept track of total consumption. Candy eaters ate less food -- compensating for the extra calories. Soda drinkers did not, so they ate more calories than usual.

A study by Richard Mattes and Wayne Campbell of Perdue University looked at the effects of food form (solid, semi-solid or liquid) on appetite.  Participants consumed either a whole apple, applesauce or apple juice of equivalent caloric value. The apple juice reduced hunger the least, the whole apple reduced hunger the most and the applesauce response was intermediate.  The participants that had the beverage apple where ready for their next meal almost an hour earlier than those that had a bitable apple.

Is satiety in our senses or in our heads?

Previous research suggests that a fluid consistency leads to less satiety.  Beverages require less chewing, and travel faster through the stomach and the intestine, explaining the lower satiety effect.

But we also eat and get full in our mind.  Could it be that it’s our mind that doesn’t see fluids as food, and therefore fails to register beverage’s calories?

To try and tease apart the physiological from the psychological a new study led by Bridget Cassady and published ahead of print in the American Journal of Clinical Nutrition devised an interesting experiment.  Fifty-two healthy adults were treated to a pre-lunch “appetizer”, consisting of 10 percent of their daily caloric needs.  Each participant experienced 4 different pre-lunch settings, all containing exactly the same amount of calories:

• Liquid to liquid: participants consumed a clear, cherry flavored drink.  Study administrators demonstrated what happens in the body by mixing the drink with what they called “gastric acid”, but was really ordinary tap water.  The mix didn’t change the liquidity of the pre-meal, therefore participants drank a liquid, and believed it remained liquid in their stomach.

• Liquid to solid: participants consumed the same clear, cherry flavored drink.  Study administrators demonstrated what happens in the body by mixing the drink with what they called “gastric acid”, but this time it was calcium chloride, which formed a solid mass upon mixing, therefore participants drank a liquid, but believed it turned solid in their stomach.

• Solid to liquid: Participants consumed cherry flavored gelatin cubes.  The study administrator imitated what happens in the stomach by mixing the gelatin cubes with “gastric acid” which in this setting was warm water, which melted the cubes, leading participants to believe that although they swallowed a solid, their stomach experienced a liquid.

• Solid to solid: Participants consumed cherry flavored gelatin cubes.  The study administrator imitated what happens in the stomach by mixing the gelatin cubes with “gastric acid” which in this setting was cold water, which didn’t affect the cubes’ solidity, leading participants to believe that they swallowed a solid, and their stomach is digesting a solid.

Hunger, fullness and appetite were assessed after each pre-meal, as well as objective measures such as blood glucose, insulin and ghrelin, stomach emptying and intestinal transit time and caloric intake in the meal following the test pre-meals.

And the results:

Liquid meals and perceived liquid meals were followed by greater hunger and less fullness.  Participants’ responses to liquid to liquid and solid to liquid pre-meals included: ”this didn’t fill me up at all” and “it hardly feels I ate anything”.  On the other hand, the solid meal (solid to solid) and perceived solid meal (liquid to solid) elicited responses such as “ I can’t remember ever being so full” and “it feels like I swallowed a rock”.

Participants ate more (in the post-test meal) when they thought they’re eating liquids – 22 percent more, which amounted to about 160 additional calories.

Stomach emptying and transit time in the colon were faster when taking in liquid or when believing the solid turned into liquid.

Insulin and other hormones signaling satiety had an attenuated rise when consuming liquids. Ghrelin, a hormone, which is suppressed after meals, was less suppressed by the liquid pre-meals.

Thinking about liquids is enough to diminish satiety

This study confirms that liquid calories cause less satiety, and also shows that just thinking about food in liquid form increases not only hunger levels but also measurable physiologic responses such as the rate in which the stomach empties and the levels of hormones that affect appetite.

Why does our body seem oblivious to the calories in drinks? Perhaps it can be explained by looking at human history: Throughout most of human times people ate food when they were hungry, and drank water when they were thirsty. Beverages with calories were rare.

Nowadays, sugary beverages constitute about a fifth of the daily caloric intake and are probably the most ubiquitous food item, available for purchase practically everywhere. These liquids calories don't seem to satisfy hunger and are therefore a source for calories that just sneak up on us.

Dr. Ayala

Full disclosure: I’m vice president of product development for Herbal Water, where we make organic herb-infused waters that have zero calories and no sugar or artificial ingredients. I’m also a pediatrician and have been promoting good nutrition and healthy lifestyle for many years.

Reposted as part of Food Renegate's Fight Back Fridays -- join the food fight!