Also see This thread on livejournal. (No-S is mentioned)
Date: April 3, 2007
Contact: Stuart Wolpert ( swolpert@support.ucla.edu )
Phone: 310-206-0511
Dieting Does Not Work, UCLA Researchers Report
Will you lose weight and keep it off if you diet? No, probably not, UCLA researchers report in the April issue of American Psychologist, the journal of the American Psychological Association.
"You can initially lose 5 to 10 percent of your weight on any number of diets, but then the weight comes back," said Traci Mann, UCLA associate professor of psychology and lead author of the study. "We found that the majority of people regained all the weight, plus more. Sustained weight loss was found only in a small minority of participants, while complete weight regain was found in the majority. Diets do not lead to sustained weight loss or health benefits for the majority of people."
Mann and her co-authors conducted the most comprehensive and rigorous analysis of diet studies, analyzing 31 long-term studies.
"What happens to people on diets in the long run?" Mann asked. "Would they have been better off to not go on a diet at all? We decided to dig up and analyze every study that followed people on diets for two to five years. We concluded most of them would have been better off not going on the diet at all. Their weight would be pretty much the same, and their bodies would not suffer the wear and tear from losing weight and gaining it all back."
People on diets typically lose 5 to 10 percent of their starting weight in the first six months, the researchers found. However, at least one-third to two-thirds of people on diets regain more weight than they lost within four or five years, and the true number may well be significantly higher, they said.
"Although the findings reported give a bleak picture of the effectiveness of diets, there are reasons why the actual effectiveness of diets is even worse," Mann said.
Mann said that certain factors biased the diet studies to make them appear more effective than they really were. For one, many participants self-reported their weight by phone or mail rather than having their weight measured on a scale by an impartial source. Also, the studies have very low follow-up rates — eight of the studies had follow-up rates lower than 50 percent, and those who responded may not have been representative of the entire group, since people who gain back large amounts of weight are generally unlikely to show up for follow-up tests, Mann said.
"Several studies indicate that dieting is actually a consistent predictor of future weight gain," said Janet Tomiyama, a UCLA graduate student of psychology and co-author of the study. One study found that both men and women who participated in formal weight-loss programs gained significantly more weight over a two-year period than those who had not participated in a weight-loss program, she said.
Another study, which examined a variety of lifestyle factors and their relationship to changes in weight in more than 19,000 healthy older men over a four-year period, found that "one of the best predictors of weight gain over the four years was having lost weight on a diet at some point during the years before the study started," Tomiyama said. In several studies, people in control groups who did not diet were not that much worse off — and in many cases were better off — than those who did diet, she said.
If dieting doesn't work, what does?
"Eating in moderation is a good idea for everybody, and so is regular exercise," Mann said. "That is not what we looked at in this study. Exercise may well be the key factor leading to sustained weight loss. Studies consistently find that people who reported the most exercise also had the most weight loss."
Diet studies of less than two years are too short to show whether dieters have regained the weight they lost, Mann said.
"Even when you follow dieters four years, they're still regaining weight," she said.
One study of dieting obese patients followed them for varying lengths of time. Among those who were followed for fewer than two years, 23 percent gained back more weight than they had lost, while of those who were followed for at least two years, 83 percent gained back more weight than they had lost, Mann said. One study found that 50 percent of dieters weighed more than 11 pounds over their starting weight five years after the diet, she said.
Evidence suggests that repeatedly losing and gaining weight is linked to cardiovascular disease, stroke, diabetes and altered immune function. Mann and Tomiyama recommend that more research be conducted on the health effects of losing and gaining weight, noting that scientists do not fully understand how such weight cycling leads to adverse health effects.
Mann notes that her mother has tried different diets, and has not succeeded in keeping the weight off. "My mother has been on diets and says what we are saying is obvious," she said.
While the researchers analyzed 31 dieting studies, they have not evaluated specific diets.
Medicare raised the issue of whether obesity is an illness, deleting the words "Obesity is not considered an illness" from its coverage regulations in 2004. The move may open the door for Medicare to consider funding treatments for obesity, Mann noted.
"Diets are not effective in treating obesity," said Mann. "We are recommending that Medicare should not fund weight-loss programs as a treatment for obesity. The benefits of dieting are too small and the potential harm is too large for dieting to be recommended as a safe, effective treatment for obesity."
From 1980 to 2000, the percentage of Americans who were obese more than doubled, from 15 percent to 31 percent of the population, Mann noted.
A social psychologist, Mann, taught a UCLA graduate seminar on the psychology of eating four years ago. She and her students continued the research when the course ended. Mann's co-authors are Erika Westling, Ann-Marie Lew, Barbra Samuels and Jason Chatman.
"We asked what evidence is there that dieting works in the long term, and found that the evidence shows the opposite" Tomiyama said.
The research was partially supported by the National Institute of Mental Health.
In future research, Mann is interested in studying whether a combination of diet and exercise is more effective than exercise alone.
UCLA is California's largest university, with an enrollment of nearly 37,000 undergraduate and graduate students. The UCLA College of Letters and Science and the university's 11 professional schools feature renowned faculty and offer more than 300 degree programs and majors. UCLA is a national and international leader in the breadth and quality of its academic, research, health care, cultural, continuing education and athletic programs. Four alumni and five faculty have been awarded the Nobel Prize.
Dieting Does not work
Moderators: Soprano, automatedeating
Interesting... but not a big surprise. I think I quote some similarly dismal statistic on the home page. I guess the really bad news is that dieting isn't just non-productive, but that it's actually harmful.
One point of confusion is the definition of "diet." Any kind of eating is a diet. Animals have a diet. And of course, I stuck the word "diet" in this system as well. I think we all understand what the difference is between the historically unprecedented and obtrusive eating systems examined in this study and "eating in moderation" (which the authors advise, and is all no-s amounts to, with a bit of clarification), but it's confusing to see the same term used for both. Instead of coming up with some new weirdo term for the old good (or at least neutral) sense of diet, I think it makes more sense to give the bad, novel concept a bad, sounding novel term. Just haven't thought of one yet...
Reinhard
One point of confusion is the definition of "diet." Any kind of eating is a diet. Animals have a diet. And of course, I stuck the word "diet" in this system as well. I think we all understand what the difference is between the historically unprecedented and obtrusive eating systems examined in this study and "eating in moderation" (which the authors advise, and is all no-s amounts to, with a bit of clarification), but it's confusing to see the same term used for both. Instead of coming up with some new weirdo term for the old good (or at least neutral) sense of diet, I think it makes more sense to give the bad, novel concept a bad, sounding novel term. Just haven't thought of one yet...
Reinhard
Just a point to nit-pick:
From 1980 to 2000, the percentage of Americans who were obese more than doubled, from 15 percent to 31 percent of the population, Mann noted.
I feel vidicated here. I think I was in 12th grade when they changed the classification of "obese" to 20+ pounds overweight (forget what it was before). That was 96 or 97. Do I think 20# overweight is healthy? Hell no! My point is that this is sneaky. By just saying "obese" they get to write about the "shocking increase" and better grab attention/make fat people feel worse without really helping. Further, this means they don't have to mention that their metric has changed by a significant amount, and this may or may not be reflected in actual trends in overweight/obesity in the actual population over time.
I would love to see this country fix its collective weight problem. But let's fix it with honesty from all angles. No sneaky crap allowed!
I do, however, agree with the article's conclusions that the only long-term successful diet is overall moderation of one's eating.
Other interesting studies lately have been looking at fatness and its relationship to socioeconomic class. These are very interesting, as the farther down one is situated in terms of socioeconomic class, the more likely one is to be obese. This is a trend. People always like to fight me on things like this, "I know fat rich people!" Yeah, but that is not the overwhelming trend all the evidence points to, those are merely outliers or are insignificant in number.
So it becomes a chicken/egg question: Does being fat cost more money and leave you poor? Or do the various stressors of poverty somehow lead to overeating? Or do overweight people experience so much discrimination that the cards of success are stacked against them, so to speak?
Regardless, the best, and from this perhaps the only real solution, is to moderate one's eating habits and exercise regularly.
Hell, it's sure easier than Atkins, vegan, low fat, zone, etc. I only wish I'd "gotten it" sooner.
From 1980 to 2000, the percentage of Americans who were obese more than doubled, from 15 percent to 31 percent of the population, Mann noted.
I feel vidicated here. I think I was in 12th grade when they changed the classification of "obese" to 20+ pounds overweight (forget what it was before). That was 96 or 97. Do I think 20# overweight is healthy? Hell no! My point is that this is sneaky. By just saying "obese" they get to write about the "shocking increase" and better grab attention/make fat people feel worse without really helping. Further, this means they don't have to mention that their metric has changed by a significant amount, and this may or may not be reflected in actual trends in overweight/obesity in the actual population over time.
I would love to see this country fix its collective weight problem. But let's fix it with honesty from all angles. No sneaky crap allowed!
I do, however, agree with the article's conclusions that the only long-term successful diet is overall moderation of one's eating.
Other interesting studies lately have been looking at fatness and its relationship to socioeconomic class. These are very interesting, as the farther down one is situated in terms of socioeconomic class, the more likely one is to be obese. This is a trend. People always like to fight me on things like this, "I know fat rich people!" Yeah, but that is not the overwhelming trend all the evidence points to, those are merely outliers or are insignificant in number.
So it becomes a chicken/egg question: Does being fat cost more money and leave you poor? Or do the various stressors of poverty somehow lead to overeating? Or do overweight people experience so much discrimination that the cards of success are stacked against them, so to speak?
Regardless, the best, and from this perhaps the only real solution, is to moderate one's eating habits and exercise regularly.
Hell, it's sure easier than Atkins, vegan, low fat, zone, etc. I only wish I'd "gotten it" sooner.
Poor =obese
I think there are a lot of reasons this equation is valid. When we were first married and money was incredibly tight, if I made spaghetti and meat sauce for supper, guess what it was long on? Not meat. Mac and cheese was 3 boxes for a dollar. We ate a lot of oatmeal and pancakes. Fluffy white bread was also a real bargain,as was boxed pasta. Applesauce was cheaper than most kinds of fresh fruit. Rice was also a bargain. I could stretch a pound of hamburger (not ground sirloin) quite far. Was this a healthy way to eat, no. But on a not-for-profit organization salary, that is what our diet consisted of. My husband and I were really into gardening and during the warm months we never lacked for fresh vegetables. I hit every store for every bargain on the planet. But by and large, highly refined carbs were the cheapest things there were.
We are doing much better now and we enjoy eating almost totally organic and healthy but a lot of the US is not so lucky. (Also, the county lost a wonderful social worker because only one of us could follow our heart and stay in this line of work if we ever wanted to own a home. But I digress). Check out the cheap food at Walmart? There isn't much nutrition there but there is fat, corn syrup and other sugars and the ever faithful presevatives and fillers.
I usually organize our social events at work and recently, because everyone there is always into some kind of diet or other (for 2 or 3 days), I suggested we have a welcome spring pot luck and everyone bring their favorite healthy dish to pass. You would have thought I asked them to eat spiders!!! I was deluged with emails saying "what do mean healthy?" "What fun is that?" "I don't like that kind of food, count me out." "No desserts?" Email after email I sat there, dumbfounded, thinking, what is the worst that could happen? You try it, you don't like it, you don't eat any more. It is only ONE meal, guys. I finally sent out an email and cancelled the pot luck. One person responded, "well, that'll teach you to try and make this group healthy." I responded, "No, that will cure me of listening to anymore talk about diet and health. Obviously, it is just talk." I only mention this because it doesn't matter if the perfect diet is ever discovered , if people are unwilling to follow it. Most of us want to eat everything we like, as much of it as we want, and as often as we want it. AND, we want to be a healthy weight and have a healthy body too. We are genuinely upset that we can't have both. We are willing to do almost no suffering to get there and stay there. I think that is why we, as a nation, are obese. We are insatiable consumers. (Actually. of more than just food.)
Let's move on to restaurants. What is cheapest? Fast food and even that isn't cheap. If you eat somewhere on a buffet, if it is cheap, the food almost doesn't qualify as food. Again, the mainstays are chips, potatoes, rice, cheese food, corn, sugar and grease. Now that we have moved up the scale of restaurants we go to, I am amazed at the high quality and good taste that is out there. So, if you are looking for a healthy eating lifestyle, health=$.
I think there are a lot of reasons this equation is valid. When we were first married and money was incredibly tight, if I made spaghetti and meat sauce for supper, guess what it was long on? Not meat. Mac and cheese was 3 boxes for a dollar. We ate a lot of oatmeal and pancakes. Fluffy white bread was also a real bargain,as was boxed pasta. Applesauce was cheaper than most kinds of fresh fruit. Rice was also a bargain. I could stretch a pound of hamburger (not ground sirloin) quite far. Was this a healthy way to eat, no. But on a not-for-profit organization salary, that is what our diet consisted of. My husband and I were really into gardening and during the warm months we never lacked for fresh vegetables. I hit every store for every bargain on the planet. But by and large, highly refined carbs were the cheapest things there were.
We are doing much better now and we enjoy eating almost totally organic and healthy but a lot of the US is not so lucky. (Also, the county lost a wonderful social worker because only one of us could follow our heart and stay in this line of work if we ever wanted to own a home. But I digress). Check out the cheap food at Walmart? There isn't much nutrition there but there is fat, corn syrup and other sugars and the ever faithful presevatives and fillers.
I usually organize our social events at work and recently, because everyone there is always into some kind of diet or other (for 2 or 3 days), I suggested we have a welcome spring pot luck and everyone bring their favorite healthy dish to pass. You would have thought I asked them to eat spiders!!! I was deluged with emails saying "what do mean healthy?" "What fun is that?" "I don't like that kind of food, count me out." "No desserts?" Email after email I sat there, dumbfounded, thinking, what is the worst that could happen? You try it, you don't like it, you don't eat any more. It is only ONE meal, guys. I finally sent out an email and cancelled the pot luck. One person responded, "well, that'll teach you to try and make this group healthy." I responded, "No, that will cure me of listening to anymore talk about diet and health. Obviously, it is just talk." I only mention this because it doesn't matter if the perfect diet is ever discovered , if people are unwilling to follow it. Most of us want to eat everything we like, as much of it as we want, and as often as we want it. AND, we want to be a healthy weight and have a healthy body too. We are genuinely upset that we can't have both. We are willing to do almost no suffering to get there and stay there. I think that is why we, as a nation, are obese. We are insatiable consumers. (Actually. of more than just food.)
Let's move on to restaurants. What is cheapest? Fast food and even that isn't cheap. If you eat somewhere on a buffet, if it is cheap, the food almost doesn't qualify as food. Again, the mainstays are chips, potatoes, rice, cheese food, corn, sugar and grease. Now that we have moved up the scale of restaurants we go to, I am amazed at the high quality and good taste that is out there. So, if you are looking for a healthy eating lifestyle, health=$.
A lot of growing up happens between "it fell" and "I dropped it."