Healthy Food & Healthy Living by Dr. Ayala

Battle of the diets: Which is best for your heart?

Misinformation is a common problem when it comes to diet advice – it spreads through diet books, blogs and social media outlets such as TikTok, Instagram and Twitter. According to Christopher D. Gardner, the director of nutrition studies at the Stanford Prevention Research Center, misinformation has reached critical levels, leading to widespread confusion about what we should eat to prevent disease and promote health.

To help us make sense of the barrage of diet messages we receive, a team of scientists, cardiologists, health experts and dietitians headed by Gardner evaluated common diet plans to determine how they comply with evidence-based guidelines for promoting heart health. Their findings appear in the journal Circulation.

So let’s start with what we know promotes heart and metabolic health: We should eat plenty of vegetables and fruit, prefer whole to refined grains, choose healthy proteins, mostly from plants, but also from fish and seafood, and if consuming meat and poultry avoid processed and fatty forms, prefer plant oils to animal and tropical oils, limit ultra processed foods, minimize sugary drinks and foods with added sugars, and moderate alcohol intake.

The best and the worst

The panel identified 10 popular diet plans. These include (1)  DASH  (Dietary  Approaches  to  Stop  Hypertension)-style, (2) Mediterranean-style, (3) pescetarian,  (4)  ovo/lacto-vegetarian,  (5)  vegan,  (6)  low-fat,  (7)  very low-fat, (8) low-carbohydrate (including Zone, South Beach, low glycemic), (9) Paleolithic (Paleo), and (10) very low-carbohydrate/ketogenic patterns (which includes Atkins and the ketogenic diet). For the several vegetarian style diets the researchers considered optimal versions of the diets – chips and soda are vegan, yet don’t represent a plant-based diet, as eating more plants is a central tenet of this food philosophy. Same applies to the other diet plans.

They then compared these popular diets to the ideal diet as defined by the American Heart Association’s dietary guidelines. Diets were ranked using a 0-100 point system.

And the results: 

The best diets are Mediterranean, DASH-Style, pescetarian, and ovo/lacto-vegetarian diets. They score high (above 85 points) because they emphasize vegetables, fruit, whole grain, healthy oils and moderate alcohol intake. They are also flexible, providing a wide range of choices. They also score high on sustainability, and have a lower environmental impact.

The lowest scoring diets: Paleo diets and very low carb/ketogenic diets with a score of under 55 points. Following these diets doesn’t align as well with dietary guidelines. These diets are promoted for weight loss and the notion that carbs are bad is widespread, but painting carbs with a broad brush eliminates healthy carbs, such as fruits, vegetables, legumes and whole grains, the cornerstone of a healthy diet. So although the Atkins and keto diet restrict some foods that should be limited, such as added sugar and refined grains, they miss the point on many other healthy, whole, fiber-rich plant based carbs, and introduce lots of animal products and fatty meats.

Taking the long view

Although the ketogenic and low carb diet may curb appetite and lead to short term weight loss, they’re not a good long-term plan. These diets often increase “bad” cholesterol levels, which can elevate the risk of heart disease, they impose a strain on the kidneys, and they’re difficult to maintain long term due to their restrictiveness. “A diet that’s effective at helping an individual maintain weight loss goals, from a practical perspective, needs to be sustainable,” says Gardner.

The Keto and paleo diets not only have a lower dietary quality, they also have a higher carbon footprint according to a recent study in the American Journal of Clinical Nutrition. The keto diet, which is a high-fat low-carb diet, is estimated to produce almost 3 kg of carbon dioxide for every 1,000 calories of food. The paleo diet, which prioritizes meats, nuts and vegetables, emits 2.6 kg of carbon dioxide for every 1,000 calories. A vegan diet, on the other hand, generates 0.7 kg of carbon dioxide per 1,000 calories – less than a fourth of a keto diet.

Common sense would suggest that it’s moderation that’s key to a sustainable, healthy diet. 

The sensible, practical, socially acceptable diet plan you can keep long term is the most promising plan for weight control and for wellness. 

Dr. Ayala

 

Can we really blame diabetes on diet choices?

Many chronic diseases are attributable, at least in part, to diet, among them are type 2 diabetes, heart disease and several forms of cancer. 

Type 2 diabetes is an enormous burden on human health and longevity worldwide, It’s has wide consequences for the people suffering from it, and on healthcare systems, as type 2 diabetes affects most organ systems including the heart, kidney, eye, brain, and liver, it increases the chances of cancers, infections, and dementia. 

Type 2 diabetes may run in families, but its rapid rise makes it clear that there’s much more than genetics at play. In the last 40 years type 2 diabetes incidence has risen 5 fold, 1 in 10 adults live with the disease and this is occurring worldwide. It’s clear that diet plays a big role, whether through weight gain and obesity or directly: by affecting sugar metabolism, inflammation, and changes in the gut. 

To what extent does your diet drive the incidence of diabetes, and which foods are most to blame?

To assess that researchers from Tufts University looked at data from 184 countries from 1990-2018. They looked at diet components, as well as age, sex, education, and where people lived. Their model relies on information from the Global Dietary Database, population demographics, global type 2 diabetes incidence estimations, and published research on how food choices impact type 2 diabetes. The findings appeared recently in Nature Medicine.

And the conclusions: about 70 percent of new cases of type 2 diabetes are attributable to a suboptimal diet and could have been avoided with a better diet. Eating too much of the wrong foods – such as refined rice and wheat, sugary drinks, processed and unprocessed meats – can explain 60 percent of the harm. Not eating enough of the protective foods – such as fruits, vegetables, nuts, seeds and whole grains – explains the 40 percent rest of the risk.

Poor diet drives type 2 diabetes in men more than in women, according to the study, in younger people more than in older ones, and in city dwellers more than in rural ones. And although men and city-dwellers with higher education tended to have a greater burden of type 2 diabetes caused by their diet, the opposite was seen in wealthier countries where living in urban areas and a higher education was predictive of a healthier diet. Interestingly, the link between a country's economic development and its diet-attributable type 2 diabetes burden has become weaker over the years – which suggests that as highly processed foods spread worldwide and expand so does type 2 diabetes.

The assessment that 70 percent of type 2 diabetes is diet related is astounding. It’s higher than previously assessed: Another study estimates 40 percent of cases are due to a suboptimal diet. This study, however, looks at 11 dietary factors instead of just six in other studies. Either way, many people could change the trajectory of their health by making healthier food choices and the biggest culprit is refined/highly processed foods – and especially refined carbs.

The diet to prevent diabetes

To lower your risk of type 2 diabetes it's important to control weight gain, which is a major risk factor for the disease. Other important lifestyle risk factors include inactivity and smoking.

Pay special attention to these diet principles to lower your risk:

Skip the sugary drinks: Excess added sugar is an established risk for diabetes, sugary drinks are the leading source of added sugar in our diet, and many studies show a clear link between soda consumption and the development of type 2 diabetes. These include randomized controlled studies that showed that sugary drinks aren’t just associated with diabetes – they cause obesity, insulin resistance and chronic inflammation, which are the harbingers of type 2 diabetes. 

Choose whole, unprocessed foods: Select whole grain over refined grains, eat nuts, beans, legumes, make sure you eat plenty of fruits and veggies (non-starchy vegetables, a potato isn’t in this category).Limit meat, especially processed meat.

Dr. Ayala

Why cooking helps with weight loss and wellness

There’s a clear link between eating home cooked meals and diet quality. Eating more home-cooked meals is also associated with lower risk of obesity.

Teaching cooking skills is an important method for improving eating habits, and is more effective than just instructing people about nutrition, but what kind of cooking should be emphasized in these lessons? 

The healthfulness of cooking practices depends on both ingredients and techniques. Health promoting cooking methods include using whole grains, adding herbs and spices, using healthy oils such as olive oil, incorporating fruits and vegetables, using onion and garlic, and using lower amounts of fat. On the other hand are health compromising cooking methods such as deep frying, use of processed foods, animal fat, processed meat, and adding sugar and sweeteners in cooking. A method for quantifying healthy cooking has been established – the Healthy Cooking Index applies a point for each health promoting behavior, and deducts a point for health compromising actions. 

A new study in Appetite looks at about 150 overweight or obese people undergoing a weight loss program. The participants were assessed for cooking practices after the weight loss intervention.

And the results: those who had a higher healthy cooking score achieved more weight loss and ate healthier.

Next, the researchers attempted to identify cooking patterns and came up with three types of cooking: Red Meat Simple, Vegetarian Simple, and Health and Taste Enhancing. 

Red Meat Simple cooks used fewer healthful additions, such as whole grains, fruit, and vegetables, or olive oil while using more red meat and animal fat and cooked meat to high temperatures. 

Vegetarian Simple cooks cooked less meat, were more likely to add fruit and vegetables, to cook with herbs and spices, use healthy cooking techniques (baking, boiling, or steaming), moderate salt and oil use, and to avoid deep frying and cooking meats to high temperatures or charring. 

The Health and Taste Enhancing cooking is characterized by higher use of taste enhancers including herbs,  spices and alliums, as well as healthful use of oils such as olive oil, fruits, vegetables, and whole grains. These kind of cooks were more likely to marinade meat prior to cooking, and to use low-fat cooking methods and moderate the salt and oil when cooking. 

The researchers found that The Red Meat Simple cooking pattern was associated with less weight loss compared to the other patterns.

Why would that be? Healthier cooking habits translate diet advice into everyday life, and make guidelines into meals. Eat-more-veggies is an abstract aspiration, while a tasty salad bowl is an adoptable habit.

Other studies have shown that hands-on cooking lessons resulted in weight loss compared to guidance followed by demonstration only.

The cooking patterns analysis hints at what's most important to impart in cooking classes: “complexity is not a necessary aspect of healthy cooking,” the authors write. “Having more advanced technical cooking skills and, in turn, making more complex dishes does not necessarily yield healthier food consumption. Promoting cooking practices that are likely to positively impact the nutritional content of the foods prepared and deterring the use of practices that are likely to negatively impact the nutritional content of foods we prepare may be more important than trying to achieve advanced levels of culinary expertise.”

Cooking plants 

Since what’s missing most from the American diet is plant based foods and whole foods, practicing kitchen skills on these ingredients is the most valuable.

A study looking at the veggie consumption and cooking skills of university students in Brazil found that less than half the students ate vegetables regularly, but knowing how to cook was significantly associated with eating veggies daily. These results are in agreement with another study of more than 1000 freshmen in the US that found that confidence in the ability to cook from basic ingredients and to follow a recipe was associated with eating more fruits and vegetables and better weight status. 

The basic skills we all need as cooks should include salads knowhow, what to make with whole grains, and a few basic cooking techniques that incorporate vegetables with grains and with protein sources, such as making a stir fry, cooking a soup, and oven roasting.

Knowing how to make healthy, tasty, simple and affordable meals is key to health and weight control, it’s a practice that’s central to wellbeing.

Dr. Ayala

Is soda bad for your brain?

One of the biggest fears we face – especially if we’re lucky enough to live a long life – is dementia. Despite great efforts to treat Alzheimer's and other dementia forms, there is no cure for this malady. Prevention is crucial.

Important modifiable risk factors for dementia are poor nutrition, binge drinking, lack of physical activity and mental stimulation and smoking.

A new study in the American Journal of Clinical Nutrition looks at a large population of almost 180,000 people in England, with no signs of dementia at the start of the study, and follows them for an average of almost 10 years. The diet of the participants was reported, and their sugary drink consumption tallied. The genetic risk of dementia was assessed for each participant looking at common genetic variants related to the risk of Alzheimer’s disease. 

During follow-up almost 1300 of the participants developed dementia. After adjusting for socioeconomic status, lifestyle factors, such as alcohol intake, smoking, exercise and weight status, and underlying health conditions that may affect dementia risk, the researchers found that those who consumed more than 2 sugary drinks a day had greater odds of developing dementia: their risk rose by some 35 percent. Excessive intake of added sugar was also linked with dementia risk.

The added risk was seen with sugary drinks, but also with artificially sweetened ones. On the other hand, those consuming moderate amounts of fruit juices did not have a higher risk of dementia. These links were not modified by genetic predisposition.

A similar study of almost 3000 people over the age of 60 years showed almost doubling of dementia risk among those with high intake of artificially sweetened drinks, and another study of 1865 people showed greatly increased risk of dementia with an intake of on average 7 sugary drinks a week.

How could sugary drinks impair the brain? It might be that the excessive sugar and rapid rise in insulin impair the brian, and for artificially sweetened drinks the authors suggest that aspartame could disrupt energy production and increase oxidative stress.

Why are sugary drinks singled out?

The western diet contains plenty of added sugar, but while sugar’s added to many foods, most of the added sugar hides in drinks – soda, sports drinks, energy drinks, flavored milks and fruit juices – the sheer amount of sugar in sugary drinks can explain why they are linked so tightly with obesity.

But studies show that there is something distinctive about getting calories in liquid form. Solid sugars suppress hunger somewhat, while liquid sugar – in sugary drinks – doesn’t affect satiety.  Sugary drinks’ calories are just added, and the meals eaten with them will be just as large, if not larger. And several studies have suggested that sugary drinks are an independent risk factor for diabetes and hypertension irrespective of obesity. 

Liquid sugar lends itself to overconsumption, and it might very well be that sugar in liquid form poses an especially tough burden on our body’s metabolism and on our brain’s function.

Dr. Ayala 

Does when and how you exercise affect your appetite?

Exercise is a cornerstone of wellness, and is independently important. Exercise is also used as a tool to control weight, but it isn’t a very effective weight loss plan when applied without a weight-loss diet. Exercise’s less than expected influence on weight loss is attributed to our body’s tendency to compensate for energy loss by increasing appetite and intake, or energy conservation and a reduction in energy expenditure. But although exercise by itself (without calorie control) doesn’t result in significant weight loss, regular exercise is linked with lower risk of gaining weight over the years. 

Does when you exercise matter?

Does the timing of exercise matter? The study of our circadian rhythm – our internal clocks that run a ~24 hour cycle related to the sun’s activity – is showing that many of our processes, including hormonal secretion, appetite, and metabolic pathways, fluctuate with the time of day. 

A new study in the current issue of the journal Appetite looks at the effect of morning vs. evening exercise on appetite, food intake and voluntary performance.

The healthy volunteers undertook two trials, in one they exercised at 10:30 am, and in the other at 10:30 pm. They ate a standardized meal 2 hours before exercise (intense cycling), and were offered a meal after exercise in which they could eat as much as they wished.

And the results: Although the participants reported similar appetite regardless of the time of day they exercised, they ate on average 150 calories more when they exercised in the evening.

This is a small study, and bear in mind that many people, especially in the US and in Europe, tend to eat more food in the evening as it is. Also, when to exercise isn’t necessarily a choice – time constraints arise throughout the day, and it’s hard enough to fit exercise as it is.

If you do have the flexibility you can experiment with timing your exercise and seeing if it helps you better control your appetite and intake. 

High or low intensity

Another method that could supposedly help with appetite control through exercise is increasing the intensity of the workout. High intensity exercise may suppress hunger more than low intensity exercise.

High intensity interval training – short intermissions of high effort sprints, interspersed with recovery periods – is rising in popularity and is sold as a time-saving and more efficient way to train than moderate intensity continuous exercise.

A new review study in Appetite collected 13 randomized controlled studies compares high and medium intensity exercise.

The researchers found that both types of exercise suppressed appetite for a period of about ½- 1½  hours, high intensity exercise to a greater extent. Which makes sense: during times of acute exercise the body diverts its resources to muscles, and puts the digestive system on hold. We also know that appetite hormones like ghrelin are suppressed during exercise.

The diminished appetite does not last however. Hunger bounces back and the post-exercise disinterest in food is short lived, regardless of exercise intensity.

The habit you can keep

The most important thing is to exercise – time and type of exercise matter less – and even if there’s no effect on weight whatsoever.

The best exercise is the one you can do, the activity that you enjoy, that’s accessible to you, that fits your schedule, that doesn’t cause you discomfort, the one that doesn’t require equipment you don’t readily have or an ill-afforded membership. 

If you still haven’t mastered an exercise habit the most important parameter is sustainability – pick a plan that you could keep and adopt as second nature, one that you can stick to.

To an active and healthy 2023!

Dr. Ayala

Is honey really better than sugar?

We’re encouraged to limit sugar and sweeteners in our diet. The American Heart Association advises no more than 6 teaspoons a day for women, 9 for men, and for added sugar to provide no more than 5-10 percent of daily calories. Excess added sugar is linked with obesity, and many chronic diseases such as type 2 diabetes, metabolic syndrome and heart disease.

And since we like sweet food –  to prefer sweet foods is to be human – are there healthier ways to sweeten food? Are honey, maple syrup, agave and date syrup any better?

Sugar is sugar?

Honey is made by honeybees from the nectar of flowers, and contains, besides sugars, a whole array of organic acids, enzymes, proteins, amino acids, minerals, vitamins, and bioactive substances. It has been shown that honey has beneficial effects on sugar control, weight maintenance, inflammation, lipid profile, and as a common cold remedy.

A new systematic review published in Nutrition Reviews including 18 controlled clinical trials set to examine honey’s health effects.

It found that a median dose of 40 grams (about 2 tablespoons) daily over 8 weeks reduced blood fasting sugar, cholesterol, and triglycerides levels. Raw honey was more effective than honey that was heat treated – most of the benefits demonstrated are from studies that use raw honey.

This review is in line with animal studies: several studies in rats show that regular honey intake results in better sugar control and lipid profiles.

Honey’s wellness benefits are plausible: Honey is 80 percent sugar, mostly fructose and glucose, but there are also “rare sugars” in honey, those include monosaccharides and their derivatives (such as isomaltulose), which have effects on fats on gut microbes. Honey contains phenolic compounds and flavonoids and other important antioxidants. Raw honey contains probiotic beneficial bacteria that are known to regulate the immune system and improve lipid profiles.

The flower source of the honey also matters – clover honey, and robinia honey were especially beneficial for fasting blood sugar control and cholesterol reduction.

Swapping sugar with honey

Honey is still in the “added sugar” category, and as such, should be enjoyed in moderation. Replacing sugar with honey can help with moderation, as you’ll be skipping most processed foods – which are made with refined sugar and high fructose corn syrup. Honey’s price point and nuisance value can help limit your consumption.

A “no refined added sugar” principal that allows for natural sweeteners can make sense if it helps you keep a lid on your sweet tooth. 

The added nutrients in honey can also add a bit of wellness.

The authors of the study also suggest that honey should not be lumped with the other refined added sugars which provide nothing but energy (empty calories): “as honey, when taken in moderation, may offer a variety of benefits for glycemic control and lipid levels.”

The key is moderation. I do believe that sweets and dessert have a place in a healthy diet. But a cake doesn't become “health food” because it’s sweetened by honey – cake is still cake.

Dr. Ayala

Why is the world getting fatter (and what we can do about it)

Barbara Corkey, PhD, has been the editor in chief of the journal Obesity for the past 20 years, so you can trust that she’s immersed in research of the causes, consequences and treatment of obesity. 

In these 20 years obesity rates in the US increased from 30 to 42 percent, and the rates of extreme obesity doubled (rising from 4.7 to 9.2 percent). Diseases for which obesity is a risk factor – such as type 2 diabetes, heart disease, stroke and some cancers – are correlated with the severity and duration of diabetes, therefore the appearance of obesity at younger and younger ages suggest a tsunami of these chronic diseases.

Corkey writes, in a recent editorial, that we humans “have developed a method to feed the billions of people on the planet, by developing processing of food with preservatives and other chemicals that can make food last longer and make it cheaper to increase calorie density in small packages.”

The cause of obesity, according to the editorial, is the foods that we make, and society overfeeding on them. 

The most consumed foods in the US are highly processed foods, topping the list are things like grain-based desserts (cakes, cookies, donuts, granola bars), chicken dishes, soda and other sugary drinks, pizza, alcoholic beverages, pasta, and beef dishes. Notably missing are fruits and vegetables and whole, unprocessed foods.

We’re now fighting for our health in a world that we humans have changed.

Surgery, drugs and the promise of culinary medicine

What does medicine offer to treat obesity? Key developments, according to Corkey, include bariatric surgery, which according to a recent study in the New England Journal of Medicine increases life expectancy by 3 years compared to the control group – but it's still 5.5 years shorter than the general population's. As to medications, there’s hope: “Novel drug combinations are beginning to close the gap with bariatric surgery and they appear to be very powerful new tools to treat obesity as a disease.”

The great hope, however: Culinary medicine. This is a new evidence based field, that combines nutrition and cooking know-how, in order to help people prevent disease and maintain health by promoting good eating habits. Culinary medicine has been added to the curricula of more than 55 medical schools, residency programs and nursing schools. The advantage of these kinds of interventions is that they can – and should – be started early, really early, before obesity sets in, and not just when illness manifests itself, and that there are no negative side effects.

Health meets food

Turning to your doctor to address obesity and diet-related afflictions is of course just one of the options at hand. 

Physicians used to get only rudimentary nutrition education as part of their training, and if they do have culinary skills it’s due to personal interests and pursuits, and not their medical education or the hospital lifestyle. Culinary skills can be gained in any number of ways: from friends and relatives, from videos and TV, from books and websites. The only way to get food that’s inexpensive, and that’s healthy for humans and for the planet is by getting cooking and preparing meals.

Much like in dentistry, where a visit with the clinician includes guidance on how to brush, floss, and strengthen your teeth, the visit with health professionals should include wellness counseling, especially nutrition education.

And cooking can also provide comfort and lots of joy. There are too many barriers to simple home food preparation, but to reverse the trend we're on, we'll have to overcome those.

Dr. Ayala

Do babies naturally hate Kale?

A new study about kale-hating fetuses captured the imagination in popular media recently. The research, published in Psychological Science, scanned about 100 pregnant women using 4D (3D made into a video) ultrasound after exposing them to vegetables, and showed more smiling fetuses after exposure to carrots, and more “cry-faces” after mom-to-be ate kale. The ability to code 4D ultrasounds and visualize the curve direction of the corner of a fetus’ mouth in the third trimester results in stunning images – cuteness factors in to make these findings more shareable, and that’s perhaps why this study made it into the Today show.

These aren’t surprising findings though. 

Many pregnant women say that their fetus reacted to certain foods they ate, perked up soon after they had a dose of their favorite flavor, and also liked the same food as a baby.

These anecdotes are supported by theoretical plausibility and some evidence. We know that a fetus develops taste buds early on in pregnancy, that the nose passages (where the organ of smell resides) are open, and inhale amniotic fluid by the end of the second trimester.  Even though the flavor and aroma receptors are not fully developed, and the fetal brain interpretations of the senses are immature, exposure to the content of the amniotic fluid does occur. We have evidence that flavor molecules, originating from mom’s diet, are present in amniotic fluid. There are also studies that show that exposure to certain flavors in pregnancy increases the chance the baby will like these flavors better once they’re introduced to new foods, in the second half of their first year of life.

As to the babies displeased with mom’s food choice: prenatal exposure may lead to better acceptance of kale later in life, and that’s something on which "future studies need to follow up,” the researchers conclude.

It’s never too early

Humans are innately fond of sweet food. But natural preference is just a starting point, as we’re creatures of instinct, but also of habituation and learning. As with many natural tendencies, a parent’s role is to modulate these in order to form healthy, adaptable behaviors in their kid. And since when it comes to food only 1 in 10 kids eat enough veggies, focusing on acquiring a flavor preference for veggies could be very beneficial.

These smiling and frowning 4D ultrasound babies are a reminder that it’s never too early: Mom’s diet during pregnancy, and if she’s breastfeeding, after birth, exposes the baby to the flavor of veggies from the very beginning, well before they eat their first pureed tomato. 

Food habits are one of these things in which timing really matters, as there’s a window of greatest opportunity to take advantage of. Generally, a baby’s first 20 months are the time they’re most open to new flavors and textures – bear in mind that babies are usually fed nothing but milk until age 6 months. Acceptance of new foods decreases after that, food neophobia (dislike of the unfamiliar) peaks at age 5 years, after which interest in new flavors and textures usually recovers.

Say yes to vegetables

Taking advantage of the high adaptability of the very young makes for a good head start with loving your veggies. 

A review, in Appetite, looked at 46 relevant scientific studies – 25 interventional studies and 21 observational ones – on promoting intake of vegetables in kids under 3 years of age. 

Repeated exposure (for 8-10 repeats) was the focus of 27 studies. All 21 experimental studies find that recurrent exposure increases intake, usually by at least about an ounce a day, and that the younger the baby, the greater the gains in veggie consumption. The 6 observational studies confirm the same trends. Some of these studies had up to 6-month follow up, demonstrating that repeated exposure led to a stable uptick in veggies.

Pay attention to the amount of repeats in these studies: Although there is a chance of success by the third exposure, it usually takes many repeats to change a baby’s mind and by the eighth exposure about 70 percent of babies will like a veggie they previously disliked. The persuasive power of repetition works on a baby the way it works on us – hence the repetitive messages and ads we shown.

And bear in mind that many things we eventually love to eat are an acquired taste – think coffee, cheese that smells like sweaty feet, garlic, hot sauce  and wine.

Exposure to a variety of veggies also seems to increase veggie intake in young kids in the 15 studies examining this strategy. When variety is piled on to repeated exposure the advantages are magnified.

Setting a veggie-loving example also helps. Parents who eat vegetables in the presence of their kids tend to have kids that eat vegetables. Three observational studies in the above review confirm that setting a good example of eating and enjoying vegetables is associated with higher frequency and intake in their young kids. And that makes sense: Most kids eventually eat their parents’ diet.

It’s never too late to fall for veggies. Try to do so yourself if it hasn’t happened to you yet; there’s lots of flavor and beauty to explore in the veggie kingdom. The finest chefs in the world are demonstrating their newly found veggie infatuation through vegetable tasting menus – why, Eleven Madison Park recently retained its 3 Michelin star status after going plant-based. Serve veggies in a positive, calm, fun, no pressure way. It also follows common sense that better-tasting, nicely prepared veggies will be better liked.

Soon enough, your kids may like kale.

Dr. Ayala

Does the microbiome affect diabetes risk?

Type 2 diabetes is a global epidemic and one of the most common conditions impacting people's health. The incidence of this chronic disease and its many consequences is rising, as type 2 diabetes now presents at younger and younger ages. It is estimated that as many as 9.3 percent of the world population had diabetes in 2019, and that by 2030 the rates will surpass 10 percent.

The risk of developing type 2 diabetes is clearly related to obesity and to genetic predisposition. Diet is also a major contributor, but not by the simplistic way people may imagine: People with no sweet tooth at all can also be at increased risk of type 2 diabetes due to poor diets; it’s not just about eating sweets and added sugars. Diabetes is an impairment of sugar metabolism, leading to too much sugar in the bloodstream instead of our cells. Diet and exercise habits affect our body’s sugar metabolism in profound ways, and the fiber and fat that you eat, and how much you move, change how your body deals with glucose, the body’s main fuel, regardless of how much candy and soda you ingest.

Partners in sugar metabolism

But it’s not just the cell's metabolic machinery, pancreatic hormones and the liver that take part in metabolizing our sugars.

Each of us is home to a whole universe of microorganisms: trillions of bacteria, fungi and viruses. Microbial life outnumbers our own cells 9 to 1, and its genetic material outweighs our own 150 to 1. Our inhabitants, our microbiome, we’re finding out, play a role in our immune system, our endocrine system, our propensity for weight gain, our risk of several diseases, our energy levels, our mental state and our mood.  

Do the microbes living in our gut affect how our body deals with sugars and our susceptibility to type 2 diabetes?

A new study in the American Journal of Clinical Nutrition looks at the evidence connecting gut microbes to insulin resistance and glucose intolerance. The researchers identified 45 relevant studies tying specific gut bacteria to sugar metabolism. 

The researchers found that several types, 6 especially, were linked with sugar and insulin metabolism. Some of these bacteria are protective and their presence is associated with lower risk, yet the presence of other bacteria is inversely correlated with diabetes risk. These links seem to be independent of weight status and of diabetes drugs.

One of the mechanisms in which gut bacteria affect health outcomes may be their production of short chain fatty acids. Short chain fatty acids are produced by bacteria when they break down and ferment dietary fiber and resistant starch. 

And indeed, the presence of short chain fatty acids and other metabolites produced by gut bacteria seems to correlate with sugar control, suggesting that short chain fatty acids may be mediating the microbiome’s effect.

Our microbiome probably plays a role in the development of diabetes. But we also, in turn, affect our microbiome to a great extent. A study in Nature finds that just 2 percent of our gut microbiome profile is genetically determined, and the rest is affected by the environment and by lifestyle.

Helping your helpers

The gut microbial community is dynamic, and depends on many factors, including age, medications, genes, exercise,  and especially diet.

Boosting a healthy microbiome doesn’t require any probiotics, nor are any lab tests, supplements or special foods needed. To improve the gut population it’s recommended you eat whole plant foods (including many types of fruit, veggies, legumes, beans, grains etc.,) lots of fiber, embrace variety in your diet, and reduce refined and highly processed foods.

Dr. Ayala

Exercise for the diet resistant

Exercise is a fundamental and super important key to wellness. Physical activity helps prevent diseases, it slows aging, and boosts mental function. It makes you look and feel better. 

But despite what junk and fast food manufacturers suggest in their clever marketing, tying sugary drinks to athletes and the olympic games, exercise will not enable you to burn off all that many extra calories, and on its own – without a reduction on caloric intake – exercise yields less than expected weight loss. 

An exercise deficit issue?

We can’t really outrun the fork and out-exercise a poor diet. 

Obesity isn’t an exercise deficit problem, it’s mostly an overeating and poor diet problem, Americans aren’t that much less active than they were a few decades ago, and exercise alone isn’t a weight loss plan, studies have shown. The calories burnt by exercise are at least partly compensated for, through energy conservation during the rest of the day and by a vigorous appetite and post-workout eating.

Most overweight people who try to lose weight don’t respond to exercise alone that much, but that doesn’t mean that exercise doesn’t help you lose weight. Exercise not only helps burn calories and keep muscle mass during weight loss, it also helps with improving your diet, as people who pursue fitness often find it easier to eat better – exercise often starts and perpetuates a virtuous wellness cycle. 

And now, a new study in eBiomedicine, part of the Lancet, finds that exercise may play a pivotal role in weight loss for a subset of people. For these people, exercise isn’t just a few more “calories out” in the energy balance sheet – exercise actually changes their metabolism.

Most people lose weight when they reduce their caloric intake, but a subset of people lose much less than expected despite adhering to diet programs. The researchers looked at the clinical records of 5000 women, and identified the 20 percentile who were most and least sensitive to diet, based on their weight loss on a 6-week 900 calorie/day supervised diet. They then studied 10 diet-resistant and 10 diet-sensitive obese women among them. These 20 women were put on a closely supervised exercise regimen. Exercise included weight lifting and treadmills, and was done 3 times a week for 6 weeks. The women were followed by weight and body composition measurements, as well as blood and muscle function tests, and muscle composition studies, using a muscle biopsy.

Flawed one size fits all 

The exercise training had minimal effect on the diet-sensitive women, but among the diet resistant women it changed body composition and muscle metabolism – it increased the mitochondrial content and metabolism in their muscle – and enhanced fat loss.

Besides offering hope for the people who find weight loss especially challenging, this study emphasizes that a personalized approach to obesity is warranted. “In cases in which diet-adherent individuals fail to achieve successful weight loss through caloric restriction, exercise may preferentially enhance their weight loss capacity by reprogramming skeletal muscle metabolism to enhance oxidative processes, consistent with our findings in biopsied muscle and derived primary muscle cells,” the authors write. 

Exercise is recommended for every human out there, for fitness’ sake, and definitely for people trying to lose weight. It may play an especially crucial role for a subset of us, whose positive and weight-altering reaction to exercise is uniquely greater, and in which physical activity over-performs.

Dr. Ayala

The rise and rise of tempting flavor and calorie bombs

Obesity rates have doubled in the US over the past three decades, and are now at about 42 percent. This rise follows a dramatic change in our food environment and our eating habits. Over the last few decades food technologists and food manufacturers have increased and popularized food products that are abundant, relatively inexpensive, calorically dense, and are what’s called “highly palatable”.

What’s highly palatable? A winning formula is one that combines sugars, fat and salt in a way that pleases our reward systems, giving us pleasure. The food industry has been busy making highly processed products from low-cost raw ingredients, and formulating them into super pleasing things to eat. They’re so pleasing that it’s hard to stop eating them – and we’re encouraged to never forget an opportunity to snack on them by massive and ever present marketing efforts.

A new study in the journal Public Health Nutrition examines just how much reformulation occurred in the past decades. While other studies focused on the rise in sugar in the American diet, the authors say theirs is the first longitudinal study of the spread of hyper palatable foods.

The researchers looked at the prevalence of hyperpalatable foods in a statistically representative US food system between 1988 and 2018 using three USDA and CDC food databases. Hyperpalatable foods were identified by criteria that look at the content and proportion of sugars, fat and salt in processed foods.

And the results: Hyperpalatable foods rose by 20 percent in three decades. Hyperpalatable foods now make up 70 percent of available foods in the US! The same grain food items were 50 times more likely to be hyperpalatable in 2018 compared to 1988. Foods in categories such as dairy and meats also went through reformulation, making them more exciting to the palate.

The authors suggest that this reformulation may be one key factor contributing to the rise in obesity: “Our findings indicate that the practices introduced to the food companies in the 1980s focused on product reformulation and enhancement may have had ongoing deleterious effects on our food system, contributing to the current obesogenic food environment in the US.”

An interesting finding is that the biggest rise in hyperpalatable foods was in ones with extra fat and salt – these are meal items and savory foods, rather than desserts and sweets. This may represent the expansion in frozen and ready to heat meals.

Resisting temptation

The authors call for public health policies limiting the addition of fat, sugar and salt to processed foods to below the threshold of hyper-palatability. 

Since that’s unlikely to happen anytime soon, the personal health solution is to minimize highly processed foods and prepared meals as much as possible. There’s a reason it’s so hard to stop eating highly processed foods – they’re designed to entice and to leave you wanting more, while at the same time giving you little nourishment. 

In this food environment it’s no wonder vegetables and fruit find it so hard to compete for attention.

Dr. Ayala

Is our love affair with protein healthy?

Americans are obsessed with protein. Fat and carbs have been vilified – for unjustified reasons for the most part; there’s nothing inherently wrong with these two macronutrients, even though some fats and refined carbs are foods to limit.

Protein on the other hand has gained a health halo, as many people think that eating more of it will build muscle and help them eat less – hence the popularity of protein shakes and powders.

The body requires protein for its upkeep – from 10-35 percent of daily calories should come from protein, or about 0.8 gram of protein per kg of weight. Athletes, children, pregnant and breastfeeding women, and older adults need more protein than the average adult. 

Protein malnutrition plagued the world in the past, and is still an issue in some parts of the world. The American diet, however, has abundant sources of protein from plants (nuts, seeds, legumes, soy, grains etc.) and from animal sources (meat, fish, seafood, cheese, eggs etc.). Pair this abundance with our appetite for protein, which drives people to pack a protein bar and jerky in their bag just in case, and most Americans get twice as much as they need.

Too much of a good thing?

What happens with excessive protein? 

It does not, as some believe, turn into extra muscle. 

If that extra protein replaces other food (perceived as having a macronutrient that’s out of favor, such as carbs), and caloric intake is adequate, you might be missing out on other nutrients that come from foods not as famous for their protein content. Focusing on protein may turn you away from vegetables, many of which also contain protein, among their very many other important micronutrients: 1 cup of broccoli has 3 grams of protein, a third of its dry weight is in fact protein. 

If that extra protein makes you exceed your caloric expenditure, its energy will be stored as fat, and you’ll gain weight. 

Excess protein is metabolized, its extra energy is stored as fat, other components are broken down and excreted. Protein's amino acids break down into nitrogen, which is excreted through the urine mainly as urea.

A high protein diet may put extra strain on the kidneys.  This is especially worrisome if there’s an underlying kidney disorder – which is not uncommon, as up to a third of Americans are at risk of kidney disease due to conditions such as diabetes and hypertension. 

A new study in Frontiers in Ecology and the Environment looks at how our excessive protein intake affects the environment, especially our waterways.

As mentioned above, the more protein you take in, the more nitrogen you excrete. Multiply that by the US population, and this makes for a significant flow of nitrogen to our waterways. Sewage actually makes 15 percent of the total nitrogen flux from land to ocean in North America. The technology that removes most nitrogen from sewage exists, but it’s expensive, and used on only 1 percent of sewage.

This human contribution of nitrogen to rivers, oceans and lakes results in excessive nutrients in the water, which lead to plant material overgrowth, toxic algal blooms, and hypoxic dead zones. It can make water unsafe to drink. “For most healthy individuals, greater protein consumption has negligible positive health benefits but is potentially deleterious to the environment,” the authors write.

The researchers analysis suggests that if Americans ate the recommended protein amounts it would reduce nitrogen losses into waterways by 12 percent. 

If you also take into account the production of our excess protein food – 60 percent of US protein intake is from animal sources – eating the recommended protein allotment will improve environmental stability much further, as the meat industry is a major contributor to greenhouse gasses and nutrient runoff.

Thinking of food as nutrients isn’t serving our health, as protein isn’t in and of itself better than fat or carbs – they’re all necessary, and can come from healthy – or less healthy – sources. Our focus should be on healthy foods and portion control. If, to increase protein intake, you replace a sugary drink with nuts or legumes this is an improvement. But opting for whey and casein protein powders and processed meat instead of whole foods is clearly a nutrition downgrade, regardless of the macronutrients involved. And this protein-overload trend has environmental costs, too.

Dr. Ayala

Are you in denial about overeating and your weight?

Denial is a powerful coping mechanism. When it comes to eating and weight issues many of us seem to be living in ignorant bliss. 

In much the same way many of us believe ourselves to be above average drivers, studies show that weight misperception is widespread. People don’t recognize overweight in themselves or in their loved ones, and even health professionals fail to identify overweight and obesity when just observing a patient. 

About 48 percent of overweight men and 23 percent overweight women considered themselves about the right weight in a study including about 16,000 people, and even among obese people only about 10 percent were aware of the extent of the extra weight they carried. About 8% of obese adults considered themselves to be "about the right weight” in another study.

We often don’t see the expanding weight on ourselves, and we don’t see it in our own kids: A meta analysis of more than 64,000 kids shows that 50 percent of parents did not identify that their kids were overweight or obese, and seriously underestimated their kids' weight status.

It may be that our eyes have acclimated to heavier bodies because so many of us are now overweight. Looking at mid 20th century footage of the movie-star-thin general public from that era surprises us, and contrasts clearly with our two-thirds-overweight/obese population. 

We’re unaware of how much we eat

We not only see ourselves as smaller than we actually are, we also underestimate how much we eat. Intake tends to be underreported by 10-40 percent according to a recent review of 59 studies, which compares people’s reports of intake to objective measures of the calories people need to eat to maintain weight (energy expenditure measured by doubly labeled water, which is the gold standard for assessing how many calories are spent).

Calorie undercounts are widespread, but studies show that overweight and obese people undercount to a greater extent.

Calories expenditure, however, is related to body mass – the larger you are the more calories you need, regardless of physical activity.

A new study including 221 people compared reported caloric intake with objective measures of energy expenditure using doubly labeled water, and also compared it to body size.

Overall, underreporting was very significant, and by as much as 1000 calories a day – had that been true people would be losing weight rather than staying the same weight or gaining some.

Obese people underreported caloric intake by as much as 42 percent. More active people also tended to underreport by almost as much: 41 percent. In comparison, thinner and more active people underreported – but by less.

But when you take into consideration body size and therefore resting energy expenditure, the absolute discrepancy between reported caloric intake and expenditure was equal: thinner people under-reported calorie intake less, but their caloric need is lower, therefore the absolute discrepancy between actual intake and caloric need was about the same.

Dietary patterns rather than calorie counts

Given the tediousness of counting calories, and the inaccuracy our self-assessed intakes, eating while counting perhaps isn’t serving us well. Regardless of the reasons why we tend to imagine we’re eating less and better than we actually are, our self deception allows us to gain weight over time.

The authors suggest that perhaps focusing on obesity-risky foods, such as high energy density foods, ultra-processed foods, foods with low fiber that cause little satiety, and sugary beverages, might better serve as dietary guidelines. Recommending a dietary pattern rather that focusing on specific foods and quantities can help curb overeating, especially since most of us are only partially aware of ourselves doing it.

Denial, again, is a natural coping mechanism, but it’s especially un-useful when interventions such as healthier eating and activity habits could have helped turn the tide.

Dr. Ayala

Eating together is a wellness tool

The family meal institution is an endangered species. Losing this important practice is worrisome, since family meals are linked with better nutrition, improved social skills, healthier eating habits, improved family connections and with lower obesity rates.

A meta-analysis in Pediatrics including 17 studies found that shared meals are linked with better nutritional health in kids – healthier weight, healthier choices and fewer eating disorders. Another meta-analysis, published in Obesity Reviews, including 57 studies with over 200,000 participants, finds that family meals are associated with lower risk of overweight, a healthier diet, and fewer unhealthy diet habits.

These pooled studies are correlational, but one can intuitively see why family meals could actually cause better habits: Family meals are usually composed of more nutritious foods, eating together enables role modeling of good habits by caregivers, it nurtures spending time and interacting with others, and it encourages slower, more mindful eating.

Frequent family meals, however, are likely more common in more organized homes, in homes with a higher socioeconomic status – homes with better eating habits and less obesity anyway.

The researchers therefore controlled for socioeconomic status in the meta-analysis, and even when controlling for socioeconomic status, more frequent family meals were correlated with better nutrition and weight status.

But whether eating together conclusively causes better nutrition or not, eating in company is a very good idea. The family meal offers a great opportunity to lead by example, communicate good habits and to bond.

Yet only about half of US households with two or more people eat meals together regularly.

Bringing families together – what works?

With busy and demanding schedules and the availability of processed and prepared foods increasing family meal frequency is challenging.

Which interventions support family meals? 

A new study in the journal Appetite looks at which interventions work best to improve the frequency and healthfulness of family meals especially among low-income families. Six different interventions were put to the test in different combinations, with 2 of the 6 intervention components tested together in each experiment, which makes for 64 different combinations. The interventions were:

• Cooking/Serving Resources: All the tools you need for cooking and serving a meal, including pots, pans, utensils, dishes etc.
• Meal Delivery: Prepared meals once a week , ready to warm up and serve.
• Ingredient Delivery: Delivery of ingredients to supply one meal a week.
• Community Kitchen: Participants were invited to a weekly group session in which you prepare one main dish to take home.
• Nutrition Education Classes: Participants were invited to attend a weekly group nutrition class that included food prep and tastings.
• Cooking Demos: Participants were invited to attend weekly group cooking lessons that included tastings.

These were tried with about 400 families recruited through Head Start, the age of children at the start of the trial was 3-4 years, and the interventions were tested for 8 weeks each.

The families were asked: “How many nights a week out of 7 did you and your child eat dinner together in the same place at home (such as around the table) for most of the meal?”. Families were also asked how many evening a week dinner was made mostly from scratch, how many nights a week dinner was cooked mostly or only from ready made foods (such as canned soup or boxed macaroni), how many nights food was from ready made dinners (such as frozen meals), and how many nights the parent/s or kid/s ate fast food (such as KFC, McDonalds) either at home or on premise.

The combination of Cooking/Serving Resources and Meal Delivery performed best and increased family meal frequency, cooking dinner from scratch, and prioritization of family meals; it also decreased the use of ready made and fast foods.

As you might imagine, supplying cooking and serving utensils, and supplying meals or ingredients garnered good participation. But getting busy parents to take part in weekly nutrition and cooking classes and demos was more challenging, and only 13-15 percent attended. Participation was so low that the researchers couldn’t even test the effectiveness of this intervention.

Eat with pleasure

Gathering around the table works even better to foster normal weight and health benefits when the atmosphere is positive. A study published in Pediatrics looks at key risk and protective factors for childhood obesity in the home, and includes 120 low–income kids and families from the Minneapolis/St Paul area, recording family meals at home for 8 days. These were all families that regularly shared meals, and told that the study focuses on “modern day” dinner, and to just eat as they always do. The video recordings were analyzed for interpersonal and food related behaviors. 

The researchers found that the atmosphere around the table matters: Families that enjoyed the meal, had warm, calm and positive conversations around the meal, had a higher frequency of normal weight. These results held true even after they were adjusted for parental weight.

On the other hand, hostility, frequent criticism, yelling, food lecturing (“children in other countries are starving”) and indulgent and inconsistent parenting were associated with heavier kids. Overweight kids also sat at the table for significantly shorter times.

Sharing meals with the people in your life depends on physical preconditions, such as arranging the time, space, utensils and food. These are barriers that may not be trivial, but well worth overcoming.

A virtuous cycle in which family members await this time to connect, talk and enjoy food and company – and reap the benefits – depends on making mealtimes as pleasurable as possible. 

Dr. Ayala

How much junk food is too much?

There’s a place for everything that’s tasty and enjoyable to eat in a healthy diet, that’s what I believe. I can also support this declaration with plenty of scientific literature showing that long lived communities as well as large cohorts in studies maintained health and avoided excessive weight gain without abstaining from dessert – traditional diets don’t declare abstinence from sweet or fried foods.

It’s the proportions that matter. If 90 percent of what you eat is nutritious you can play with the rest. If 80 percent of your days are reasonably active, hibernating couch-potato style on a lazy day will do no harm.

But here’s the problem: Our proportions have turned upside down, completely. 

Junk all around

A new study in the Journal of Nutrition assesses the amounts of junk food in the American diet using two nationally representative data sources, including more than 10,000 people.

What is junk food? The academic literature struggles with this question. Salty snacks, candy and soda are the hallmark representatives, but there are many other products – such as bakery products, sweet breakfast cereals, fast-food and processed meats – that should be in the eat-less/junk category.

This study uses the 2016 Chilean law for food labeling and advertising definitions of junk food. This law identifies foods with high caloric density, high added saturated fat, sugar and salt, and imposes marketing and advertising regulations upon them, including warnings on the front label and a ban from sales in schools.

And the results: Between 2015-2018 almost half of daily calories US adults consumed were derived from junk food. Sugary drinks composed almost half of the sugar from these junk food.

This study paints a picture concordant with another study in kids, that finds that 56 percent of the calories US kids consume come from junk food.

This current study also found that there are disparities in junk food intake among ethnic groups, with non-Hispanic black adults consuming more junk food, and with the highest income group consuming the lowest amount of sugary drinks.

You are what you eat 

Obesity, type 2 diabetes, hypertension and many other chronic conditions are nutrition associated diseases – they could be avoided or ameliorated by a healthy diet and lifestyle.

We know that the more junk food in a society’s diet the greater the obesity rates. A recent large prospective study found that a 10 percent increase in ultra-processed food is associated with a 10 percent increased risk in overall cancer and breast cancer rates. A study following 12,000 Americans with no underlying illnesses for more than two decades found a 30 percent higher risk of dying in the group consuming more junk food.

If people just replaced junk foods they’d likely gain less weight and perhaps shed some.

A study in the BMJ simulated what would happen if kids reduced their junk food intake, and estimated that childhood obesity rates would drop from 20 to 11 percent, and there’s be 16 percent fewer overweight kids. This simulation extrapolates from a randomized controlled trial in which people alternated between highly processed and less processed diets which were matched for total calories, energy density, carbs, protein and fat, fiber, sugars and salt and instructed to eat as much as they wanted. People on a junk food diet consumed on average an additional 500 calories daily than they did on an unprocessed diet.

You know it when you see it

As to the definition of junk food, no system of categorizing food will be perfect, and we can debate whether warnings on the front of the package are the best way to reduce the intake of what’s inside.

Although academics may struggle with the definition of junk food, for the most part, we know junk food when we see it. The problem is that we see so much junk that it's normalized. Mainstream supermarket’s shelves sell more highly processed and junk food than wholesome ones, pharmacy and convenience store shelves stock almost nothing but junk, and advertising efforts focus almost only on these products. 

It’s really no surprise that half of what Americans eat is junk when so much of what’s offered to them in reality and digitally is these highly processed sugary drinks, candy, fast food, mass produced chips, highly sweetened cereals and cured meats.

Dr. Ayala