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Dr. Ayala

Dr. Ayala
Philadelphia, Pennsylvania, USA
V.P. Product Development
Herbal Water
I’m a physician (Pediatrics and Medical Genetics), artist, and mother of 3 school age active kids. I recently co-founded Herbal Water Inc. (www.herbalwater.com) with my husband, Albert. I am a serious home cook, and love to entertain. My expertise is vegetarian food (I have been a vegetarian all my life). I strongly believe that eating healthy and enjoying good food go hand in hand. My main interests are science, nutrition and art, and I am overall a very curious person that tries to learn something new every day. Dr. Ayala (Ayala Laufer-Cahana M.D.)


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JUNE 29, 2011 8:24AM

Study suggests the best and worst foods for healthy weight

Rate: 7 Flag

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 withless 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


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Excellent tips and more for sound dietary control.
From recent personal experience, I can attest to the validity of the facts you present here. I lost 30 pounds last summer over a three-month period on an eating program that excluded fried foods of all kinds, processed meats, salt and all but a minimal amount of sugars. I have maintained the loss ONLY by continuing to avoid those same foods. Every time I wander away from portion control and lean meats, fruits and vegetables, my weight goes up enough to see it on the scale.

This makes perfect sense to me. I recently read a book called "The end of overeating" by David Kessler. He talks about this very thing, but his theory is that sugar/salt/fat laden foods are addictive because they're so super tasty. You body has a reaction to them much like a drug. I know for me, I never gorge on fruits, veggies and whole grains, I just eat enough to get full. But when it comes to chicken wings or macaroni and cheese, I often leave the table with a stuffed tummy and feeling very guilty.
I always thought nuts were fattening. The rest is a no brainer though. Potato's have always been the bane of anyone watching their weight and common sense should tell you that if you dump 300 calories into your body every time you hydrate it you are going to be a disgusting fat body in no time.
@Rw005g Oh, don’t get me started on food subsidies – they are a major culprit of why we’re eating so much highly processed foods.

There is a wonderful program in Philly called The Food Trust: http://www.thefoodtrust.org/. They are doing some great work in bringing healthy food to food-deserts and to people will fewer means.

The Food Trust and the Philadelphia Department of Public Health launched the Philly Food Bucks program, which encourages SNAP/food stamp recipients to use their benefits to purchase fresh, local ingredients at participating farmers’ markets throughout the city.

Is that the kind of initiative you're looking to see?
@bluestocking : I, too, enjoyed Kessler’s "The end of overeating". There’s gathering evidence that the sugar/fat/salt combo is indeed addictive and makes us to overeat and never be satisfied.
I'm wondering if wine or beer was part of the study?
@Lane Brooks
The study's findings related to alcohol were complex: Increases in alcohol use were associated with weight gain, but there were differences between alcoholic drinks and the sexes...overall the findings were inconsistent, and the authors suggested further research was needed.
Oh my word...you're reading my mail!
Nevertheless, I have no doubt that our obesity crisis is a result of overeating.

As a doctor, are you familiar with the work of Dr. Arya Sharma, a bariatric physician (i.e., someone who studies these issues intensely) from Canada? He has written several posts recently discussing two - of many - recent studies that show, in fact, that "calories in, calories out" is a false and outdated model of understanding obesity. To quote him: "Whoever said that treating obesity was simply a matter of ‘eating less and moving more’ (ELMM) probably also believes that they can live forever by simply breathing less."

For example, in a post entitled "Eating More Calories Increases Weight (In Some People - Sometimes - Maybe)," he describes several recent peer-reviewed and governmental studies:
- Austin et al. (2011, Am J Clin Nut) found that the increase in caloric intake between 1971-2006 was actually greater for "normal" vs. overweight or obese men, and was only slightly greater in obese vs. "normal" weight women - and further, those extra calories consumed were likely used due to the extra energy required to move heavier bodies.
- the extensive 2007-09 Canadian Health Measures Survey found that obese children and adults get very similar quantities of exercise (and, again, the slight differences seen are more than made up for by the extra calories burned on a per-minute basis by heavier individuals).
- Beyerlein et al. (2011 PlosOne) found that obese and thin children have similar levels of risk factors (e.g., hours watching TV), but that children at the upper levels of the BMI distribution (i.e., those most sensitive to obesogenic factors) are the only ones who gain weight in response. (see full summary here: http://www.drsharma.ca/obesity-overweight-kids-more-sensitive-to-obesogenic-environment.html)

In his post "Why Diet and Exercise is Not a Treatment for Obesity" (http://www.drsharma.ca/obesity-why-diet-and-exercise-is-not-a-treatment-for-obesity.html) he describes one of the many recent peer-reviewed studies (MacLean et al. 2011 Am. J. Physiol. RICP) showing the strong homeostatic pressure that forces weight-reduced individuals to regain via multiple metabolic pathways, most notably leptin. These factors ultimately increase hunger pangs and cravings, meanwhile reducing the metabolic rate by 20% or more.

Then there's the recent research into gut flora and viruses, both of which lead susceptible people to both extract more calories out of food than others, and to store more energy as fat - all summarized in this 2006 New York Times article: http://www.nytimes.com/2006/08/13/magazine/13obesity.html

I could go on, as there are many more studies with similar results, but I think you get the idea. Obesity is FAR more complicated than simply eating less and moving more. Yes, there certainly are people who ate themselves above their set weight and can easily lose those extra pounds by cutting a few calories and walking a bit more. These are the people you see trumpeted as success stories.

But for those people who have genetic susceptibility (and/or gut flora, and/or viruses) to obesity - and who, worse, have often further slowed their metabolisms over years of dieting and weight-cycling - it is by no means that easy. I say this as a woman who eats a primal (low calorie, low carb, low fat) diet of 1200-1400 calories, exercises intensely on a near-daily basis, yet still has a BMI of >35 - and I am far from alone in this situation.
Thank you Dr. Ayala I will keep this in mind while I work on my goal weight. It seems easy to get addicted to soda and other sugary substances as well as extremely difficult to stop consuming them. Is there any methods to stop the cravings?
A friend of mine once commented to me that nobody becomes obese from eating too much fruit. I was downing pounds of cherries in season and mildly concerned about it. I think she was right though. One may go broke from eating too many cherries at roughly $6 a pound, but when cherries-obsessed, I don't also crave french fries.
The epidemiology of overweight and obesity: public health crisis or moral panic?

1. Paul Campos1,*,
2. Abigail Saguy2,
3. Paul Ernsberger3,
4. Eric Oliver4 and
5. Glenn Gaesser5

+ Author Affiliations

1School of Law, University of Colorado, CO, USA
2Department of Sociology, University of California, Los Angeles, CA, USA
3Department of Nutrition, Case Western Reserve University School of Medicine, OH, USA
4Department of Political Science, University of Chicago, Chicago, IL, USA
5Curry School of Education, University of Virginia, VA, USA

1. *Corresponding author. E-mail: paul.campos@colorado.edu

National and international health organizations have focused increasingly on a perceived obesity epidemic said to pose drastic threats to public health. Indeed, some medical experts have gone so far as to predict that growing body mass will halt and perhaps even reverse the millennia-long trend of rising human life expectancy.1 In response to such concerns public health agencies across the world have sprung into action, searching for policies or incentives to mitigate the alleged ‘disease’ of obesity.

Yet even as the volume of alarm grows louder, a growing number of researchers, drawn from a broad array of academic disciplines, are calling these claims into question. The authors of this article come from this latter group. In our view the available scientific data neither support alarmist claims about obesity nor justify diverting scarce resources away from far more pressing public health issues. This article evaluates four central claims made by those who are calling for intensifying the war on fat: that obesity is an epidemic; that overweight and obesity are major contributors to mortality; that higher than average adiposity is pathological and a primary direct cause of disease; and that significant long-term weight loss is both medically beneficial and a practical goal. Given the limited scientific evidence for any of these claims, we suggest that the current rhetoric about an obesity-driven health crisis is being driven more by cultural and political factors than by any threat increasing body weight may pose to public health. "Claim #1: 'Almost all countries (high-income and low-income alike) are experiencing an obesity epidemic … WHO, 2003 (p. 61).2"

The claim that we are seeing an ‘epidemic’ of overweight and obesity implies an exponential pattern of growth typical of epidemics. The available data do not support this claim. Instead, what we have seen, in the US, is a relatively modest rightward skewing of average weight on the distribution curve, with people of lower weights gaining little or no weight, and the majority of people weighing ∼3–5 kg more than they did a generation ago.3 The average American's weight gain can be explained by 10 extra calories a day, or the equivalent of a Big Mac once every 2 months. Exercise equivalents would be a few minutes of walking every day. This is hardly the orgy of fast food binging and inactivity widely thought to be to blame for the supposed fat explosion.

While there has been significant weight gain among the heaviest individuals4 the vast majority of people in the ‘overweight’ and ‘obese’ categories are now at weight levels that are only slightly higher than those they or their predecessors were maintaining a generation ago. In other words we are seeing subtle shifts, rather than an alarming epidemic. Biologist Jeffery Friedman offers this analogy: ‘Imagine that the average IQ was 100 and that five percent of the population had an IQ of 140 and were considered to be geniuses. Now let's say that education improves and the average IQ increases to 107 and 10% of the population has an IQ of >140. You could present the data in two ways. You could say that average IQ is up seven points or you could say that because of improved education the number of geniuses has doubled. The whole obesity debate is equivalent to drawing conclusions about national education programmes by saying that the number of geniuses has doubled.’

In the US, to take a much-cited example, the so-called ‘obesity epidemic’ is almost wholly a product of tens of millions of people with BMIs formerly in the 23–25 range gaining a modest amount of weight and thus now being classified as ‘overweight’, and, similarly, tens of millions of people with BMIs formerly in the high 20s now having BMIs just >30. This movement of population cohorts from just below to just above the formal definitions of overweight and obesity is what public health officials are referring to when they point out that rates of obesity have exploded over the course of the last generation. (Furthermore, there is some evidence that adult and childhood BMI may have ceased to increase, as shown by comparison of NHANES data from 1999 to 2000 and from 2001 to 2002).5

In any case the real question is whether these developments represent some sort of genuine health crisis. This is true only if crossing the threshold of BMI 25 or 30 is analogous to contracting a life-threatening disease. But this analogy holds only to the extent that overweight and obesity actually cause increased mortality.
Sorry, didn't include that that long section is from the "International Journal of Epidemiology".

Enjoy and try to relax folks.
I think it's important to remember that junk food is created for no other reason than to be hard to resist and addictive once your resistance fails. A chip or a soda is a man-made work of genius designed to appeal to your ancient, animal brain and outwit our very modern ideas of not eating every bit of fat,sugar or salt when it comes within our vicinity. For thousands of years it was acutally a good idea to do that, it's only been relatively recently that we've had the opposite problem, and even more recent still that we've had industrial giants ploughing enormous scientific and marketing resources into convincing us to eat too much of the wrong thing.