4.05.2008

what i'm reading: rethinking thin

I just finished Rethinking Thin: The New Science of Weight Loss - and the Myths and Realities of Dieting, by Gina Kolata, who is a science writer for the New York Times.

The book is framed around a university-sponsored weight loss study, a highly controlled and supported experiment to see which of two diets results in more weight loss. Around this framework, Kolata takes you through the history of the diet and weight loss industry (it's much older than I thought!), and an examination of the available scientific evidence about weight loss.

Kolata's examination of the data brings her to these conclusions:

  • Humans have very little control over their weight. Your weight is about 80% genetically determined. You can affect your weight only within a small range.

  • Being overweight is not a serious health risk. Other than the morbidly obese, being fat in itself has very little effect on your health. In fact, being what society considers slightly overweight appears to extend life span and promote good health. (Note that this is a separate issue from exercising and eating healthfully. You can do both and still be overweight.)

  • No diet works better than any other diet. As every chronic dieter knows, you can lose some weight on almost any diet, and you will always gain it back, and then some. This is not merely observational and anecdotal. It is fact.

  • People are becoming fatter, but it's not their fault, and may not even be bad, except, of course, socially. An analogy can be drawn to height. In the last century, people in first-world countries have become taller. This is not because humans have changed genetically, but because, for the first time in history, changes in medicine and nutrition has enabled humans to fulfill their genetic potential for height. According to the data, the same goes for weight. It appears that humans have an enormous potential to store fat, and only now, as a large segment of the population has access to unlimited nutrition, are we seeing that.

  • Data that supports the above conclusion - no matter how rigorous the study, no matter how clear the evidence - are attacked, ignored or dismissed. Studies that support socially acceptable conclusions - no matter how flawed the study or flimsy the evidence - are promoted. This is a running theme of Rethinking Thin, and alone makes the book worth reading, for the general comment on the uses of science in society.

    When I wrote about eating disorders, experts were beginning to see data that supported these ideas. I waited for the news to filter down to the general public - and kept waiting. It never happened. Rethinking Thin explains why.

    It's a short book and easy to read. Some of the science was a bit beyond me, but that was a minor part, and didn't affect my overall understanding.

    The conclusions of Rethinking Thin are certainly controversial. But before anyone dismisses them as hocus-pocus, I would read this.
  • 19 comments:

    Nigel Patel said...

    I had always assumed the height thing came from the high concentration of meat in the English and then North American diet.
    All that protien in the growing years.

    And I'm a bit afraid to say so in such a health consious city as this but a lot of the eating-right/healthy-living looks a little fettish'y to my eyes.

    L-girl said...

    It is fettishy, for sure. But so is the whole weight loss thing.

    Re height, access to protein does figure in. But people in first-world countries are (on average) taller now than they were 100 years ago.

    M. Yass said...

    Data that supports the above conclusion - no matter how rigorous the study, no matter how clear the evidence - are attacked, ignored or dismissed. Studies that support socially acceptable conclusions - no matter how flawed the study or flimsy the evidence - are promoted.

    Not just socially acceptable conclusions, but those supported by - you guessed it - the diet and pharmaceutical industries.

    Personally, I agree with Penn & Teller that the obesity epidemic is bullshit. Personal example: By the widely accepted Body Mass Index chart, my maximum "healthy" weight is 173.75 pounds. But get this: I could weight up to 189 pounds and still be qualified for U.S. Army Ranger School.

    I really think the BMI standard is set to a level that is impossible for most people, especially those who work desk jobs, to achieve and sustain. 'Course, that's good for the economy because that means Big Pharma gets even richer.

    I also shudder to think how much this is affecting young girls who have body image issues.

    L-girl said...

    Not just socially acceptable conclusions, but those supported by - you guessed it - the diet and pharmaceutical industries.

    Yes indeed. And, Kolata shows, the academic scientific community as well. Gazillions of dollars in grants depend upon it.

    I really think the BMI standard is set to a level that is impossible for most people, especially those who work desk jobs, to achieve and sustain.

    BMI is supposed to be a big improvement over simple weight, because it takes height into account. But it doesn't measure fat vs muscle. For example, I am very muscular. I am not thin, but my weight on the scale is deceptive, because muscle is very dense. So would I be healthier if I my BMI was lower, but I had no muscle tone?

    Well, according to Kolata - and she has a huge amount of excellent evidence to prove her case - the obesity "epidemic" is definitely bullshit.

    I also shudder to think how much this is affecting young girls who have body image issues.

    Me too. It's awful. Young girls - and not-so-young girls and women, too.

    Nancy said...

    Actually, much of the weight gain in the American population can be tied to the following developments over the past forty years:

    1. Larger portion sizes in restaurants. A restaurant in France will serve an entree that is about half the size of an American one.

    2. Increased consumption of junk food, high fructose corn syrup, etc.

    3. Less exercise, coincident with the rise of computer culture and home entertainment.

    This doesn't mean it's healthy or natural. But it's been my experience that most people (including myself) will do anything to lose weight except close their mouths.

    Nancy said...

    Oh, and the BMI is crap. It doesn't take into account that people have different sized skeletons/body frames. My ideal BMI would put me at what I weighed when I was 18 years old. The ONE time I was at my ideal weight, I was about 20 pounds over the 'BMI'. This after diet and exercise and a total detox...
    so I know what should be the right weight. It just won't be on some chart.

    L-girl said...

    1. Larger portion sizes in restaurants. A restaurant in France will serve an entree that is about half the size of an American one.

    Americans who only eat at home and never eat in restaurants show the same weight gain as those who eat only in restaurants.

    It's also been shown that people who eat more in one sitting - such as a large restaurant meal - eat less the next day without even trying. The amounts we eat stay very stable over the course of a week, no matter how they fluctuate on a daily basis.

    Both of these have been proven many times over.

    2. Increased consumption of junk food, high fructose corn syrup, etc.

    Again, no evidence shows that junk food consumption is up as compared to 20 or 30 years ago, or that families who eat more junk food are heavier. Many people eat a lot of junk food and stay slim.

    3. Less exercise, coincident with the rise of computer culture and home entertainment.

    Americans are actually more active now than they ever have been. Actual *evidence* shows that.

    You are repeating the accepted wisdom, but there is actually no evidence to support it.

    Americans are actually eating less and dieting more than ever before, because of the endless repetition and exhortations of what you have written here. They are losing weight - and gaining it back.

    most people (including myself) will do anything to lose weight except close their mouths.

    This is simply not true.

    If you believe "all you have to do is eat less" then you are subscribing to an outdated, disproven, and even dangerous myth. Eating less slows down your metabolism and makes it even more difficult to lose weight.

    Dieters *do* eat less. They do it strictly for days, weeks, months, even years. Millions of Americans do this. They lose some weight, and they gain it back. That also has been proven over and over and over again.

    And it's not because they didn't "close their mouths".

    You might want to get some more information about these myths that you, like so many people, cling to.

    Nigel Patel said...

    Travelers have been reporting the largess of American portions VS Western Europe, and the relatively lower prices of food, since the nineteenth century.
    If Gore Vidal can be trusted.

    L-girl said...

    Nige, you're right. It's also a myth that Europeans aren't getting heavier. It's something everyone hears and repeats, but the facts don't bear it out. People in all first-world countries have gotten heavier. They've also gotten healthier!

    FatLady said...

    I will probably run to the library for this one. I've been reading everything I can get my hands on on the subject.

    If you believe "all you have to do is eat less" then you are subscribing to an outdated, disproven, and even dangerous myth. Eating less slows down your metabolism and makes it even more difficult to lose weight.

    Boy have I learned that the hard way. Years of yo-yo dieting, fasting, severe calorie restricted diets have ruined my metabolism.

    Once upon a time I was the poster child for the diet/weight loss industry. I bought every diet book, tried every diet, bought every piece of gimmick-y exercise junk--not to mention $100 pairs of walking shoes. Until I mangled my knee a few years ago, I walked everywhere. Since then, I've been losing the battle in a "Big" way.

    I weigh more now that I ever have --and in fact I'm on the fast track to a gastric bypass now. As BARBARIC a procedure as I think it is, I probably need to go through with it to save my own life.

    I've been beating myself up for years--feeling like a failure and like victim of my own weaknesses. Why? Because I can't live on 1000 calories a day for more than a week before I freak out.

    Some day the scientists will figure this all out but meanwhile I'm on my way to surgically enforced anorexia--which has its own irony because I was actually "normal" weight when I started dieting as a teen. I just thought I was fat--and saw a fat girl in the mirror. Now they recognize that as an eating disorder.

    a lot of the eating-right/healthy-living looks a little fettish'y to my eyes.

    Yes, I agree. Nevertheless, I need to be a bit "fettish'y." (I like your word.) I need to read labels in the grocery store--or avoid all prepared foods entirely. I need to not eat any refined sugar, simple carbs, yada yada yada. Life would be so much simpler if I could eat what everyone else does--but I can't.

    Humans have very little control over their weight...Being overweight is not a serious health risk...No diet works better than any other diet.

    These are the things being said in the fat acceptance movement. Oh how I wish there had been FA people around me when I was in high school and beyond--when I was still "normal" weight or only slightly "obese" by the old weight/height charts.

    I also shudder to think how much this is affecting young girls who have body image issues.

    Oh but while we're handing out "demon awards" let's not forget the fashion industry! Size ZERO indeed!

    Nancy said...

    l-girl, you're the one offering absolutely no proof of your arguments.

    I've lived in France, and know that the French eat a higher fat diet than Americans. They have no junk food, do NOT eat between meals, and portions are minute compared to the ones Americans eat in restaurants. And at home. Happy now?

    And Americans TALK a lot about exercise. I don't know too many people who are doing it.

    I can offer proof that the portion size, corn syrup, and rise of the computer (inactivity) have a lot to do with the fattening of the American public. You might want to try doing the same, and not dismiss my points out of hand with no proof at all.

    L-girl said...

    I will probably run to the library for this one. I've been reading everything I can get my hands on on the subject.

    It's really good. You'll get a lot out of it.

    Boy have I learned that the hard way. Years of yo-yo dieting, fasting, severe calorie restricted diets have ruined my metabolism.

    Same here. I was a chronic dieter for years (and years and years...), until my metabolism was completely effed up. It's healthy again, but it took a lot of hard work to get it that way - and to keep myself from dieting now.

    Once upon a time I was the poster child for the diet/weight loss industry. I bought every diet book, tried every diet, bought every piece of gimmick-y exercise junk--not to mention $100 pairs of walking shoes.

    Me too.

    For me it's been a matter of accepting myself as weighing more than I'd like to, appearance-wise, but realizing I am healthy and ok anyway.

    I've been beating myself up for years--feeling like a failure and like victim of my own weaknesses. Why? Because I can't live on 1000 calories a day for more than a week before I freak out.

    Just like individual appetites for everything else in life vary, the need to eat, and how much we eat, varies too. Some of us have bigger appetities than others. It's not your *fault*. It's just *you*.

    I was actually "normal" weight when I started dieting as a teen. I just thought I was fat--and saw a fat girl in the mirror. Now they recognize that as an eating disorder.

    I'm so sorry to hear that. After I wrote about eating disorders, I started recognizing them in so many people, including myself and my sister.

    I need to read labels in the grocery store--or avoid all prepared foods entirely. I need to not eat any refined sugar, simple carbs, yada yada yada. Life would be so much simpler if I could eat what everyone else does--but I can't.

    If I may... two things here.

    One, I don't think that caring about what goes in your body is fettishy at all. I think of it as self-care and self-respect. I am a voracious label reader, because I don't want to eat chemicals and processed sugar and HFCS and tons of sodium - because it's not healthy. I think of that as a very positive step towards caring about myself.

    Two, don't assume that "everyone else" can eat whatever they want. There's a world of people out there struggling with their weight. You are not alone.

    You're healthier because you read labels and choose food wisely. That's a good thing.

    Oh but while we're handing out "demon awards" let's not forget the fashion industry! Size ZERO indeed!

    Fashion industry, retail industry, television, movies, magazines, Barbie dolls...

    I know when we meet IRL, you might compare our relative sizes and say that I'm not fat. But I am *way* over any size I ever dreamed I'd be comfortable with, and it's been a loooong struggle to accept myself this way.

    Good luck with your surgery. I know several people who've been very happy since theirs.

    L-girl said...

    l-girl, you're the one offering absolutely no proof of your arguments.

    Read the book that this post is about. It's chock full of proof. I'm not about to recreate all Kolata's research here.

    L-girl said...

    I don't know too many people who are doing it.

    Your personal knowledge - of people in France, of how many Americans exercise, of people's computer use - is not considered proof. Nor is mine.

    I'm referring to rigorous, controlled studies that go beyond the scope of any one person's experience. Adoption studies, twin studies, longevity studies, studies that track food intake and exercise, studies of the effectiveness of dieting, and so forth.

    If the subject really interests you, I invite you to read this book and come back and tell me what you think.

    If you prefer to believe you already know everything there is to know on the subject, then conversation is pointless.

    Nancy said...

    Watch SUPER SIZE ME, the film about McDonalds' made by Morgan Spurlock. He eats an extreme version of the American fast food diet and winds up with a liver that nearly fails, and gains a tremendous amount of weight.

    I don't need to use my opinions, just my eyes.

    L-girl said...

    Nancy, I have seen Super Size Me, I loved it. Nowhere in this post do I say a fast food diet is healthy. Nowhere in her book does Kolata say that.

    However, it is still a fact that our weight is about 80% genetically determined. This is not something either you or I can see with our eyes. It's a fact.

    You know, it was once believed that rotten meat gave rise to maggots. Everyone knew it was true because they saw it with their eyes.

    It was believed the sun revolved around the earth.

    It was believed the earth was flat.

    All those things were seen with people's eyes. So of course they had to be true.

    Like I said, if you are interested in learning more about this topic, I recommend this book, Rethinking Thin. It pulls together dozens of sources.

    redsock said...

    I've lived in France ... They have no junk food...

    Really? Are you sure?

    I don't need to use my opinions, just my eyes.

    You might want to schedule an appointment with an optometrist.

    P.S. Anecdotes are not evidence.

    M@ said...

    Well, it's been on my mind lately for some reason...

    McDonald's was surprisingly pervasive in France. There was a "McDrive" at almost every highway exit we passed last week in Brittany, Normandy, and especially in Ile-de-France. Not to mention Quick and many other burger and pizza places. There was a fast food or pizza place in every little town we visited -- including the town we stayed in, with its population of about 3000. Presumably someone's eating the stuff.

    The highway rest stops (which were a necessity for us as we were travelling some longish distances and wanted to minimize our time on the road) were filled with various kinds of junk food. We saw Pringles being eaten a lot as well -- both by children and adults. It seems to be a common snack food.

    Boulangeries always stock an array of cakes and pastries (mon dieu, les pains chocolats!) which, I feel safe in assuming, are also eaten between meals from time to time.

    It seems to me that the prevailing ideas about French eating habits are either out of date or completely mythical.

    L-girl said...

    It seems to me that the prevailing ideas about French eating habits are either out of date or completely mythical.

    That's interesting to hear.

    One thing that is easily forgotten, comparing (eg) US body weights to weights in France is that the US is very mixed genetically. If African-American and Latina women are genetically more prone to being overweight than white Europeans, it could easily appear that Americans are simply fatter than the French. But that difference is not necessarily behavioural.

    * * * *

    The assumptions people make are very interesting, too.

    I eat an incredibly healthy diet. I eat no fast food whatsoever. I don't overeat and I get prodigious amounts of exercise. And I am overweight.

    One of my co-workers who lives on McDonald's and similar crap is thin as a rail.

    Now those are two "with my own eyes" anecdotes. But they don't figure in to the assumptions. I am overweight, therefore I don't control my eating and I am lazy. She is skinny so she must be doing everything right.