John Nguyen
04-11-2007, 05:24 PM
This is the message a group of researchers is sending, saying that not only does dieting not work in the long term, but it is also potentially dangerous for your health.
The study is published in the April edition of American Psychologist, the journal of the American Psychological Association and details the work of researchers from the University of California, Los Angeles, who reviewed 31 long-term studies lasting between 2 to 5 years.
UCLA associate professor of psychology and lead author of the study, Traci Mann said: “You can initially lose 5 to 10 percent of your weight on any number of diets, but then the weight comes back. We found that the majority of people regained all the weight, plus more,” she added.
“Diets do not lead to sustained weight loss or health benefits for the majority of people,” said Dr Mann, shattering an age-long belief that restraining from food for a period of time will help a person lose weight – and keep it that way.
The study suggests that whatever benefits there are to be obtained through dieting, in the long run, negative side effects outweigh advantages. Dr Mann and her team analyzed every study they could find that followed people on diets for 2 to 5 years.
Studies that take less than 2 years are “too short to show whether dieters have regained the weight they lost,” they said. They found that it would have been better for most of them if they had not gone on a 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,” explained Dr Mann. Repeatedly losing and gaining weight has been linked, in previous studies, to cardiovascular disease, stroke, diabetes and altered immune function.
While people on diets lose an average of 5 to 10 per cent of their weight in the first 6 months, 33 to 66 per cent of these persons regain more than what they lose within 4 to 5 years.
And this is not a complete picture either. The figures do not reflect reality because participants phone or mail their results in themselves, without an impartial assessor. Also, many studies have a below 50 per cent follow up rate; and the people who put on a lot of weight are less likely to stay in touch.
UCLA graduate student of psychology and co-author of the study, Janet Tomiyama said that “Several studies indicate that dieting is actually a consistent predictor of future weight gain.”
She referred to a study that studied links between lifestyle and weight in 19,000 healthy older men over four years. This study 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,” she said.
Dr Mann said: “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.”
The study did not name any diets in particular, but looked at a broad spectrum of approaches. Professor Mann said in her opinion eating in moderation was a good idea for everybody as was regular exercise.
The study is published in the April edition of American Psychologist, the journal of the American Psychological Association and details the work of researchers from the University of California, Los Angeles, who reviewed 31 long-term studies lasting between 2 to 5 years.
UCLA associate professor of psychology and lead author of the study, Traci Mann said: “You can initially lose 5 to 10 percent of your weight on any number of diets, but then the weight comes back. We found that the majority of people regained all the weight, plus more,” she added.
“Diets do not lead to sustained weight loss or health benefits for the majority of people,” said Dr Mann, shattering an age-long belief that restraining from food for a period of time will help a person lose weight – and keep it that way.
The study suggests that whatever benefits there are to be obtained through dieting, in the long run, negative side effects outweigh advantages. Dr Mann and her team analyzed every study they could find that followed people on diets for 2 to 5 years.
Studies that take less than 2 years are “too short to show whether dieters have regained the weight they lost,” they said. They found that it would have been better for most of them if they had not gone on a 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,” explained Dr Mann. Repeatedly losing and gaining weight has been linked, in previous studies, to cardiovascular disease, stroke, diabetes and altered immune function.
While people on diets lose an average of 5 to 10 per cent of their weight in the first 6 months, 33 to 66 per cent of these persons regain more than what they lose within 4 to 5 years.
And this is not a complete picture either. The figures do not reflect reality because participants phone or mail their results in themselves, without an impartial assessor. Also, many studies have a below 50 per cent follow up rate; and the people who put on a lot of weight are less likely to stay in touch.
UCLA graduate student of psychology and co-author of the study, Janet Tomiyama said that “Several studies indicate that dieting is actually a consistent predictor of future weight gain.”
She referred to a study that studied links between lifestyle and weight in 19,000 healthy older men over four years. This study 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,” she said.
Dr Mann said: “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.”
The study did not name any diets in particular, but looked at a broad spectrum of approaches. Professor Mann said in her opinion eating in moderation was a good idea for everybody as was regular exercise.