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.

 

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 

 

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. 

 

 

Cities Fighting Soda

Several city health departments are stepping up their anti-soda efforts in an attempt to curtail obesity and diabetes. Philly is now airing its own TV spot, which my kids had noticed and brought to my attention over the dinner table.

There's quite a wide range in the messaging tactics each city takes.  NYC's campaign certainly caused a stir, especially the "Are You Pouring On The Pounds" video, which was deemed too disgusting by some. Take a look at these different approaces.  Which works best in your opinion?

Philly:

 

New York: 

 

 

Boston:

 

See LA's media campaign here and Santa Clara's here.

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.

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!

Are low glycemic diets better for your heart?

How much we eat matters a whole lot, and the bottom line is that too many calories, no matter what their source, will lead to weight gain and the myriad of health consequences related to overweight, including increased risk of heart disease, diabetes, stroke and some cancers. 

But what we eat matters, too, and lots of study and experimentation addresses the issue of which foods and nutrients (fat varieties, protein, carbs) lead to better health and better chances of losing weight and keeping it off.  The connection between the fat in the diet -- more specifically the saturated fat component -- and heart health is a much-studied topic.  But could different carbs and protein matter just as much?

Low Glycemic eating pattern and heart disease risk

All carbohydrates are not created equal -- at least not by the way our body responds to them.

The glycemic index, developed initially for the treatment of diabetes, ranks carbohydrate-containing foods based on how they affect blood sugar levels when eaten in isolation. Carbs that break down quickly, like white bread and potatoes, have a high glycemic index, and those that release sugar into the blood stream more gradually, like fruit, have a low glycemic index. Foods are scored on a scale of 0 to 100.

Glycemic index’s proposed effect on both metabolism and health outcomes seems quite plausible: Blood glucose fluctuations elicit a cascade of hormonal reactions, which can potentially affect satiety, hunger, blood lipids and inflammation.

And indeed, a few short term studies show that a low glycemic diet can decrease hunger and control weight regain.  The glycemic index is taken into consideration in many popular weight management plans, including the South Beach Diet, Nutrisystem, the Zone diet and Sugar Busters.

And now, a new study in Circulation looks at how different weight maintenance diets -- differing in glycemic index and protein content -- affect heart disease risk.  The study group of about 500 overweight people first lost weight over 8 weeks on a low calorie diet.  After shedding about 8 percent of body weight the participants were randomly assigned to one of 5 diets, which they successfully maintained for 6 months:

• Low glycemic low protein
• High glycemic low protein
• Low glycemic high protein
• High glycemic high protein
• Control diet: healthy diet conforming to national standards

Heart disease develops over very long periods of time, so what the investigators studied were markers, known risk factors for heart disease, one of which was C-reactive protein (CRP), a protein found in the blood, and the levels of which indicate inflammation.  Low-level inflammation is believed to be the cause of many disease processes and to be prevalent in overweight people.

Here are the study’s main findings:

• During the 8 weeks of calorie restriction and rapid weight loss all the participants had a marked improvement in blood pressure, blood lipids (cholesterol profile) and CRP.
• During the 26 weeks of weight maintenance period only the two groups on a low glycemic diet experienced further reduction in CRP. Protein content and further weight loss didn’t affect the connection between low glycemic diets and lower CRP.
• Despite lower body weight, once the low-calorie diet was replaced by the maintenance diets, cholesterol and LDL (‘bad’ cholesterol) returned to baseline.
• And since I know you're wondering: The best diet for weight maintenance was the low glycemic/high protein one -- after 6 months the high glycemic/low protein group gained about 4.5 pounds more compared to the low glycemic/high protein group.

Could low glycemic diets affect inflammation?  The authors cite several studies that also found that low glycemic diets are associated with lower CRP, and suggest that high blood glucose after meals stimulates the expression of inflammatory genes.  

Is low glycemic the next Atkins?

I hope that after all these decades of going all-the-way with low carb, low fat and other simplistic, total sweeping rules – to no avail -- we’ve learned that nutrition is both exceedingly complex and at the same time practically quite simple.

Low glycemic eating patterns seem to have growing scientific support.  Low glycemic foods correspond quite often with the age-old understanding of what’s good to eat. Most highly processed grain products have a high glycemic index, whereas minimally processed grains, whole fruits, legumes, and non-starchy vegetables tend to have a moderate or low glycemic index.

On the other hand pure fructose and ice cream have a very low glycemic index, table sugar and high fructose corn syrup have only a moderate one, and potatoes and white rice are the root of all glycemic evil, with a glycemic index of about 100.

So clearly, glycemic index is only one of the parameters we need to think about when selecting carbs, but food choices cannot be made using glycemic index alone.

The glycemic index also has plenty of shortcoming: It’s difficult (and costly) to test the glycemic index of food, there’s inter-lab variability, the type and proportion of sugar or starch in a food affects glycemic index but so do a lot of other factors in the meal—the way the food’s been cooked, the presence of fiber, protein, fat, alcohol or acid all affect the glucose response—and there’s plenty of individual variability.  Finally, the glycemic index of the food matters much less than how much of that food you’re eating.   To really make the glycemic index useful you’ll need to calculate the glycemic load -- taking into account the glycemic index, the percentage of carbs in the food and the portion size – a better predictor of how your blood sugar will be affected by that certain meal component.

So while the glycemic index might be worth thinking about, especially for diabetics and overweight people, adhering to a healthy diet, rich in fruits, veggies and whole grains and avoiding highly processed junk is probably good enough practical advice for most of us –- and it has the added advantage of standing the test of time.

Dr. Ayala

 

Study shows a daily can of soda has measurable harmful effects

There is very little doubt that drinking sugary drinks regularly is associated with obesity, type 2 diabetes, hypertension and heart disease. 

Since sugary drinks are the leading source of added sugar in the American diet, and it’s quite easy to take in lots of calories in beverages without much effect on satiety, a lot of the harm done by consuming sugary drinks can be explained by the weight gain associated with their consumption.

But there’s another school of thought, and growing supporting research, that believes that sugars -- and especially the fructose component of sweeteners -- are especially harmful to our health, and have direct adverse effects on fat metabolism and inflammation. 

Our metabolism on sugary drinks 

A previous study from the University of California at Davis showed that drinking 25 percent of daily calories in fructose for 10 weeks increased triglycerides and cholesterol and caused insulin resistance in people, while drinking the same amounts in glucose didn’t. And while both the fructose and the glucose groups gained weight during the study, the fructose group gained more belly fat.

Indeed, a concerning finding, but drinking 25 percent of calories in fructose is something very few of us do (although many teens do take in about 20 percent of their calories in added sugars, and do so daily for many years).

Now, a new study, led by Isabelle Aeberli, and published in the American Journal of Clinical Nutrition, looked at 29, young, healthy, non-overweight men, who drank more reasonable amounts of sugary drinks containing different levels of fructose, glucose or sucrose (which is a glucose/fructose mix). 

(Quick reminder: Our foods and drinks are usually sweetened with sucrose (table sugar) or high fructose corn syrup (HFCS); both types of sweeteners are a combination of the simple sugars glucose and fructose.) 

Each participant spent 3 weeks on each of the following 6 beverage regimens, with a 4-week washout between interventions: 

• Medium fructose: 40 g of fructose a day

• High fructose: 80 g of fructose a day

• Medium glucose: 40 g of glucose a day

• High glucose: 80 g of glucose a day

• High sucrose: 80 g of sucrose a day

• Control: No sugary drinks at all

Just to put the sugar content in perspective: The medium sugar interventions are equivalent to drinking 1 can (12 oz.) of coke/day; the high sugar interventions are equivalent to drinking 2 cans (24 oz.) of coke/day. 

The experiment lasted about 44 weeks; here are some of the main findings:

• Waist-to-hip ratio increased in the medium fructose, high fructose and high sucrose interventions (higher waist-to-hip ratios indicate abdominal obesity, which is associated with an increased risk of heart disease and type 2 diabetes)

• Fasting glucose levels increased in all five sugary drink interventions

• C-reactive protein, a marker of inflammation, increased in all 5 sugary drink interventions, with the highest values seen in the high fructose intervention.  Inflammation is a key factor in the development of both heart disease and type 2 diabetes

• There was a reduction in large, buoyant LDL particles when participants were consuming fructose drinks (high and medium fructose and high sucrose interventions).  A regular lipid profile measures only total LDL, which didn’t change between interventions; we now know that there are subclasses of LDL, and the smaller LDL molecules pose more risk and have a higher tendency to block arteries.  The large buoyant LDL is, as the name implies, flexible and bouncy, and causes less lumps and blocks.

• All sugary drink interventions lead to some increase in caloric intake

• Leptin (a hormone that regulates appetite and metabolism) increased in the medium and high glucose interventions, but not in the fructose and sucrose interventions

What can we learn from this study?

The first conclusion we can draw from this study is that fructose does seem to cause more damage than glucose – fructose leads to lipid abnormalities and more belly fat accumulation.  On the other hand all sugary drink regimens, including the moderate glucose exposure, had pretty unhealthy results: all 5 interventions increased markers of inflammation and increased caloric intake.

The practical, real-life understanding is that all sugary drinks, even in what many would consider “moderate” amounts, seem to have a measurable undesirable effect after as little as 3 weeks. 

As far as I know there are no popular drinks in the market sweetened by glucose; practically all forms of caloric sweeteners used in food processing are a glucose/fructose mixture.  Cane or beet sugar are sucrose (table sugar), which is a two-sugar molecule with exactly 50 percent glucose, 50 percent fructose. HFCS is about 45 percent glucose, 55 percent fructose. Fruit juice concentrate's sugar composition will depend on the fruit source: Apple juice concentrate is about 30 percent glucose, 70 percent fructose, while orange juice concentrate is about 50 percent glucose 50 percent fructose.  Agave syrup is about 70-75 percent fructose.

All sugary drinks contain fructose, and if this study’s findings are confirmed in larger and repeated studies, there’s reason for worry.

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.

Do French fries and soda make you fat?

This may seem like a silly question, since all food provides calories, and you can potentially eat too much of anything and fatten up.

On the other hand certain foods and lifestyles do seem to be associated with overeating and weight gain.

And since weight loss is ever so difficult and once achieved even harder to maintain, figuring out which eating pattern is more likely to prevent weight gain over the years can offer a logical preventive plan for addressing our obesity crisis.

Which foods are linked with weight gain? To answer this question, a new study in the New England Journal of Medicine tracked changes in the eating habits of more than 120,000 professionals -- who all started out as non-obese -- while following their weight for about 20 years.  The study’s findings shed some light on weight gain over time.

Weight gain is slow and insidious

For most people, weight gain isn’t a dramatic event.  Weight, much like aging, changes so slowly that you don’t notice it at all; until one day enough change has taken place that your image in a photo puts you into a state of shock.

In this study the average weight gain was about 3.5 pounds every 4 years – just under 1 pound-a-year – which really isn’t that much, yet over the 20 years of follow-up participants gained an average of 17 pounds.

French fries and sugary drinks linked to weight gain; Fruits, veggies, nuts and yogurt linked to weight loss

Certain foods were independently related to weight gain.  The foods showing the largest effect were:

• Potato chips and French fries
• Sugar-sweetened beverages (soda and other sugary drinks)
• Unprocessed and processed meats 

Other foods were associated with weight loss:

• Vegetables
• Whole grains
• Fruit
• Nuts
• Yogurt 

Is a calorie not a calorie?

Is there something special about fried potatoes and sugary drinks that makes them especially fattening? Isn’t it surprising that adding nuts to your diet – nuts are some of the most caloric-dense foods on the planet – was associated with less weight gain?

The authors, led by Dariush Mozaffarian, from the Harvard School of Public Health, offer this explanation: Dietary quality (the types of foods and beverages consumed) influences dietary quantity.  Increasing the consumption of veggies, fruits and nuts probably reduced the intake of other, more caloric-dense foods, overall decreasing caloric intake.  Whole, unprocessed foods have more bulk, are digested slowly, and probably cause more satiety.  Drinks, other studies have shown, are less satiating than solid foods.  This study, too, showed that all caloric drinks except milk were associated with weight gain.

There’s another possible explanation: People who care about healthy weight tend to also care about healthy eating, therefore both weight maintenance and healthy eating just happen to go together, because people who are committed to not gain weight also eat healthy. Eating fruits, vegetables and nuts is also linked to being physically active, but definitely doesn’t cause it.  Good habits tend to cluster, and it’s very difficult to prove cause and effect with these kinds of things.  (It took quite a lot of research to figure out that while healthy people tend to take vitamins, taking vitamin supplements doesn’t make you any healthier.)

Nevertheless, I have no doubt that our obesity crisis is a result of overeating.  It’s a fact that most of the extra calories we’ve added over the past 30 years come from highly processed foods, refined carbs and starches and sugary drinks.  Is there something unique about these foods that makes overeating them more likely?  I think this study provides some support to the notion that the answer is yes!  There’s also plenty of evidence that these processed foods are bad for our health, and their overconsumption is linked with chronic disease.

Dietary quality probably does influence dietary quantity; it’s just easier to eat fewer calories when you’re eating well.

Dr. Ayala

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

The American Academy of Pediatrics Advises Against Energy and Sports Drinks

Energy and sports drinks are aggressively marketed to kids and teens. Not only is engaging in a sports activity – however casually and briefly – a reason to “rehydrate” with a sports drink, kids are now encouraged to consume sports drinks before, during and after thinking of moving a muscle. Sports drinks are sold in many school’s vending machines, and judging by ads for energy drinks our young ones couldn’t stay alert or study were it not for shot after shot of energy in liquid form.

Are these drinks of any benefit?

The American Academy of Pediatrics' (AAP) committee on nutrition and council on sports medicine and fitness reviewed the scientific literature and consulted with many experts for its new clinical report on sports and energy drinks. In order to clear some of the confusion around these products the report starts with a few definitions and ingredient lists:

• Sports Drinks - these contain sugars (2-20 grams of sugar per 8 oz serving, or 30-200 calories per bottle), electrolytes (sodium, potassium), minerals (calcium, magnesium), flavoring and sometimes vitamins. They are supposed rehydrate and replace water and electrolytes lost during exercise.

• Energy Drinks - these contain sugars (0-31 grams of sugar per 8 oz serving, or 10-270 calories per container) stimulants, such as taurine, guarana and caffeine, vitamins and other supplements. Energy drinks deliver stimulants, which supposedly improve performance.

Sports drinks: For serious athletes playing prolonged, vigorous sports in a the heat

For all non-prolonged less exhausting occasions the AAP report warns that the extra calories in sports drinks may lead to extra body weight, and the combined sugar and acid in them causes dental erosion.

As for the heavily marketed beneficial and functional ingredients in sports drinks: electrolytes are plentiful in food, protein and amino acids as well as vitamins are plentiful in food, and the specific amino acids added to sports and energy drinks to enhance performance (glutamine, arginine, taurine) have not been proven beneficial by good clinical trials.

Energy drinks: Totally unsuitable for kids and teens

The report stresses that energy drinks “pose potential health risks primarily because of stimulant content; therefore, they are not appropriate for children and adolescents and should never be consumed.”

Eliminate sugary drinks: Drink water!

The expert panel concludes:

“Given the current epidemic of childhood overweight and obesity, we recommend the elimination of calorie containing beverages from a well balanced diet, with the exception of low-fat or fat-free milk, because it contains calcium and vitamin D, which are particularly important for young people.”

We're very far off from the AAP's target: A recent CDC survey found that one in four high school kids drink soda every day and two in three drink a sugary drink every day. This is actually an improvement -- in previous surveys three-quarters of kids reported drinking a sugary drink each day.

When celebrity athletes drink sugary drinks in ads they do it because they’re paid handsomely to do just that. In real life star athletes usually treat their bodies like a temple. I’m pretty sure they watch what they eat quite carefully, and maximize their potential by eating well. An image that better reflects an athlete’s genuine eating habits is Rafael Nadal’s on-court water and banana combo (Nadal’s often seen snacking on a ripe banana between sets).

A sports drink with breakfast and lunch doesn’t make an athlete – it just makes kids poorly nourished and fat.

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.

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The sugar wars: Is fructose the main villain?

There is very little doubt that drinking sugary drinks regularly is associated with obesity, type 2 diabetes, hypertension and heart disease.

But does drinking sugar just make us consume too many empty calories, or is there something inherently unhealthy about sugar? Is high fructose corn syrup (HFCS) the villain? Is old fashioned sugar any better or just as bad? Will agave (with its low glycemic profile) save us? And what’s all this talk about fructose being toxic?

Food sugar 101

Our foods and drinks are usually sweetened with sugars that are a combination of the simple sugars glucose and fructose. Sucrose (table sugar) is a two-sugar molecule with one glucose and one fructose bound together, and is therefore exactly 50 percent glucose, 50 percent fructose. HFCS is about 45 percent glucose, 55 percent fructose. Fruit juice concentrate's sugar composition (stripped down concentrated fruit juice is really just sugar!) will depend on the fruit source: Apple juice concentrate is about 30 percent glucose, 70 percent fructose, while orange juice concentrate is about 50 percent glucose 50 percent fructose.

Agave syrup, favored by those adhering to a low glycemic diet, is about 70-75 percent fructose.

What you need to remember is that practically all forms of caloric sweeteners used in food processing are a glucose/fructose mixes. Although only HFCS has fructose in its name, all our commonly added sugars contain both fructose and glucose. Corn syrup stands apart as a pure glucose sweetener, but since pure glucose is less sweet than HFCS or sucrose, it isn’t economic – or tasty -- to use.

Is fructose more harmful than glucose?

A study from the University of California at Davis, led by Peter Havel, made headlines a couple of years ago when it showed that drinking 25 percent of daily calories in fructose for 10 weeks increased triglycerides and cholesterol and caused insulin resistance in people, while drinking the same amounts in glucose didn’t. And while both the fructose and the glucose groups gained weight during the study, the fructose group gained more belly fat.

The study concluded that drinking lots of fructose lead to unique adverse effects on lipid metabolism, insulin resistance and abdominal obesity, effects not seen when drinking the same amounts in glucose.

What explains our body’s different reaction to these two sugars? The authors hypothesized that since fructose is metabolized in the liver, fructose sweetened beverages affect the liver’s metabolism of fats; glucose is metabolized in every cell of the body, doesn’t need as much of the liver’s attention, and therefore the adverse metabolic effects weren’t seen in the glucose beverage drinkers.

But one question lingered: Could high levels of blood sugar and blood insulin explain fructose’s adverse metabolic outcomes?

To answer that question the authors went back to study the blood samples of the people enrolled in their initial study. They published the findings of their new research in the American Journal of Clinical Nutrition (published online ahead of print). Havel’s group found that the 17 people who were drinking 25 percent of their calories in fructose were actually consuming a diet with a lower glycemic index, and their blood glucose and insulin after meals were lower than the fluctuations seen in the 15 people consuming 25 percent of calories in glucose.

To conclude, in this 10 week study, drinking fructose caused dislipedimia and insulin insensitivity unrelated to blood sugar and insulin levels. On the other hand drinking glucose caused rollercoaster peaks and troughs of blood glucose and insulin, while not causing dislipedemia.

The dose makes the poison

Fructose is metabolized by the liver, and this study supports the notion that its excess consumption plays a part in causing insulin resistance (which leads to diabetes), high cholesterol and triglycerides (all risk factors for heart disease) and the tendency to accumulate belly fat (a risk factor for a myriad of diseases, including heart disease, high blood pressure and cancer).

While drinking glucose may not affect our fat metabolism in the same way fructose does, glucose causes spikes in blood sugar and blood insulin – which are not good either.

If you’re concerned with fructose, you should be concerned with the intake of all the sweeteners that contain fructose -- that includes not only HFCS, but also cane and beet sugar (table sugar), molasses, agave, brown sugar, fruit juice concentrates and honey.

I don’t personally believe glucose or even fructose are evil. Our body, especially our brain, runs on simple sugars, and sugars, including fructose, are a natural part of very healthy foods, such as fruits and veggies.

It is excess sugar – of any kind – that is harmful. The dose makes the poison.

Excess sugar is hard to come by in nature unless you run into a beehive and the bees are willing. It takes a lot of berry picking to hit your liver with the fructose dose that is anything similar to what’s in a can of soda. Only processed foods, and especially sugary drinks, hit your liver with that much fructose at such high speed. Fructose containing foods in nature have fiber (and much less sugar) and break down slowly. On the other hand processed foods and especially sugary drinks have no fiber – just lots of fructose – and we’ve shown a tremendous capacity to chug them down real quick.

Does the study’s experiment resemble real life? On one hand, the study group drank 25 percent of daily calories in sugar. We’re bad but not that bad: A recent study shows that our teens consume 21 percent of their daily calories from added sugar.

On the other hand, the study lasted for 10 weeks. Our kids are ingesting a large proportion of their daily calories as glucose/fructose mixtures for years and years.

Considering the current evidence, this is not an experiment we should be conducting.

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.

Further reading/viewing:
• Dr. Robert Lustig explores the damage caused by sugary food in this controversial & much viewed video: Sugar: The Bitter Truth.
• Gary Taubes’ New York Times Magazine article: Is Sugar Toxic?

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

Diet soda and the metabolic syndrome

Some foods seem like a lesser evil initially, only to reemerge as even worse than the food they replaced.

The big shock was when we found out that replacing butter (high in saturated fat) with margarine (polyunsaturated fat), was discovered many years later to not only decrease our joy in eating (in my opinion reason enough to reject margarine) , but introduced trans-fats to our body, which are apparently worse than saturated fat.

Are we now going to discover that diet soda is as damaging as regular soda?

Several reports have demonstrated that increased consumption of soft drinks is linked to the growing epidemic of obesity and type 2 diabetes in childhood and adolescence.

But a new study published this week in Circulation observes that “Western Diet” and diet soda specifically, promote the incidence of the Metabolic Syndrome.

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. It seems like wherever the Western dietary patterns of eating spread, obesity and the metabolic syndrome follow, with increased incidence of diabetes and heart disease not far behind.

The findings of this study, led by Lyn M Steffen, emerged from an analysis of dietary intake of 9,514 participants aged 45 to 64 years old followed for 9 years.

Researchers assessed food intake using a 66-item food frequency questionnaire. From those responses, they categorized people by their dietary preferences into a “Western-pattern” diet or a “prudent-pattern” diet.

In general, the “Western-pattern” diet was heavy on refined grains, processed meat, fried foods, red meat, eggs and soda, and light on fish, fruit, vegetables and whole grain products.

“Prudent” diet eating patterns, by contrast, favored cruciferous vegetables (e.g., cabbage, radish and broccoli), carotenoid vegetables (e.g., carrots, pumpkins, red pepper, cabbage, broccoli and spinach), fruit, fish and seafood, poultry and whole grains, along with low-fat dairy.

Researchers also assessed associations with individual food items: fried foods, sweetened beverages (regular soda and fruit drinks), diet soda, nuts and coffee.

After these nine years of follow-up, 3,782 (nearly 40 percent) of the participants developed the metabolic syndrome.
After adjusting for demographic factors, smoking, physical activity and energy intake, consumption of a “Western” dietary pattern was adversely associated with metabolic syndrome.

When Steffen and colleagues analyzed the results by specific foods, they found that meat, fried foods and diet soda were all significantly associated with increased risk of metabolic syndrome, but consumption of dairy products was beneficial.

The strong association between diet soda consumption and the metabolic syndrome was surprising to the authors. Diet soda has no sugar and no calories, so one would assume it does not contribute to poor glucose control or obesity. However, this is not the first time diet soda is implicated in the metabolic syndrome. Recent data from the Framingham Heart Study found a 56% increased risk for the Metabolic syndrome among those consuming 1 or more servings of diet soda per day.

The authors discuss this finding, and cite a study in rats, that suggests that artificial sweetener consumption impairs the body’s ability to predict the caloric content of food, and may lead to increased intake and weight gain.

Further studies will hopefully help elucidate why diet sodas don’t seem to be the answer to the growing waist line.
Dr. Ayala