Sherrie
03-10-2006, 04:24 PM
I was reading this, this morning and thought it was a good read:
Vol. 12 No. 4 ~ July/August 1998
Rethinking Low-Fat Advice
In April 1986, we published our first article linking high-fat diets to obesity. It was our first scoop, then barely reported in a few scientific journals.
It was a shocking idea -- that eating fat could increase body fat.
For over two decades Americans had been eating a high-fat diet, reportedly up to 45 percent of total calories. Nutritionists, physicists, and biochemists were telling their students, "a calorie is a calorie is a calorie," -- calories do not differ in fuel value or effect on fat storage.
We reviewed the then little-known work of Wayne C. MIller, Elliot Danforth, Jr., J.P. Flatt, and their colleagues at the University of Illinois, the University of Vermont, the University of Massachusetts, and the University of Lausanne in Switzerland. The evidence from those early studies was overwhelming and convincing.
Before long the public was being advised to cut down on fat to ward off obesity and for heart health. People responded, slowly at first, and then in a rush that has taken on a terrible momentum of its own. Our fat intakes is now 34 percent of total calories, with a further drop to 30 percent being urged.
We have long championed the advice to reduce fat in the diet. But in recent years we have backed off somewhat, watching in horror the havoc wreaked by dire warnings that dietary fat "causes" obesity, aligned with the most severe pressure ever seen from the health community and the media to be extremely thin.
Americans have taken the antifat message to heart. College women strive to eat "zero" fat, according to university nutritionists, who evaluate some of their diets at only 4 percent fat. Up to 81 percent of 10-year-old girls in a California study have disturbed eating; they are afraid to eat fat and feel guilty when they do. Health-anxious, thin-obsessed parents wean their babies on skim milk, and stunt their growth. Many teenage girls, already the most poorly nourished of any group in America, have stopped drinking milk or eating meat in their extreme fear of fat. Dysfunctional eating, eating disorders, size prejudice, nutrient deficiencies, malnutrition, and deaths and injuries from weight loss attempts are apparently increasing. And obesity rates have not dropped, but mushroomed.
Many scientists, pediatricians, and nutritionists are having second thoughts about the low-fat advice.
In this issue of Healthy Weight Journal, scientists debate the question: Is dietary fat responsible for rising obesity rates? The answers are not at all simple. In humans it is difficult to separate the effects of fat from other features of modernization: sedentary lifestyles, abundance of cheap food, the appeal of sweet, highly-processed foods, and the role of advertising in promoting overeating. Further, genetics clearly plays a role, especially the "thrifty genotype." Animal research reveals individual and strain differences in response to high-fat diets.
Health problems related to low dietary fat also are beginning to surface. Low-fat diets lower the "good" HDL cholesterol levels. There are concerns about the lack of essential fats; children especially may suffer nutrient deficiencies. Low-fat diets may harm some individuals, benefit others. Ronald Krauss, head of the American Heart Association's nutrition committee, reports findings that one third of people increase their risk of heart disease on a low-fat diet, while one third benefit and another third are unaffected.
Further, lowering fat intake often means lowering diet quality, when people turn to more high-sugar, calorie-dense, low-fiber, highly-processed foods. While trying to lower fat, Americans have increased their daily energy intake by about 200 calories in 5 years.
Adding to the confusion are the health effects of different kinds of fats. New findings about transfatty acids (as in vegetable oils made solid in shortening and margarine) and an overbalance of omega-6 polyunsaturated fats linked to heart disease and breast cancer complicate the once-simple advice to reduce saturated fats.
Should we then decrease some fats, increase others? Or suspend judgment for a time?
Especially interesting and reassuring is Andrew Prentice's research (page 55) suggesting that if people do not overeat, it does not make much difference whether fat is 10 or 80 percent of calories. A high-fat diet, then, may promote obesity only when we overeat.
This supports the position of nutritionists who believe the widespread disruption of normal eating and mealtimes, the high levels of dieting and disordered eating, the overriding of hunger and satiety signals, that have occurred in the last two or three decades, bear some responsibility for increased obesity rates.
What today's consumers seem to need most is a break from the overemphasis on fat. It has diverted them from key health messages, such as the benefits of eating in moderation, balance, and variety, and of eating normally and living actively.
Frances M. Berg,
Healthy Weight Journal Editor
http://www.healthyweight.net/editor.htm#98-4
Vol. 12 No. 4 ~ July/August 1998
Rethinking Low-Fat Advice
In April 1986, we published our first article linking high-fat diets to obesity. It was our first scoop, then barely reported in a few scientific journals.
It was a shocking idea -- that eating fat could increase body fat.
For over two decades Americans had been eating a high-fat diet, reportedly up to 45 percent of total calories. Nutritionists, physicists, and biochemists were telling their students, "a calorie is a calorie is a calorie," -- calories do not differ in fuel value or effect on fat storage.
We reviewed the then little-known work of Wayne C. MIller, Elliot Danforth, Jr., J.P. Flatt, and their colleagues at the University of Illinois, the University of Vermont, the University of Massachusetts, and the University of Lausanne in Switzerland. The evidence from those early studies was overwhelming and convincing.
Before long the public was being advised to cut down on fat to ward off obesity and for heart health. People responded, slowly at first, and then in a rush that has taken on a terrible momentum of its own. Our fat intakes is now 34 percent of total calories, with a further drop to 30 percent being urged.
We have long championed the advice to reduce fat in the diet. But in recent years we have backed off somewhat, watching in horror the havoc wreaked by dire warnings that dietary fat "causes" obesity, aligned with the most severe pressure ever seen from the health community and the media to be extremely thin.
Americans have taken the antifat message to heart. College women strive to eat "zero" fat, according to university nutritionists, who evaluate some of their diets at only 4 percent fat. Up to 81 percent of 10-year-old girls in a California study have disturbed eating; they are afraid to eat fat and feel guilty when they do. Health-anxious, thin-obsessed parents wean their babies on skim milk, and stunt their growth. Many teenage girls, already the most poorly nourished of any group in America, have stopped drinking milk or eating meat in their extreme fear of fat. Dysfunctional eating, eating disorders, size prejudice, nutrient deficiencies, malnutrition, and deaths and injuries from weight loss attempts are apparently increasing. And obesity rates have not dropped, but mushroomed.
Many scientists, pediatricians, and nutritionists are having second thoughts about the low-fat advice.
In this issue of Healthy Weight Journal, scientists debate the question: Is dietary fat responsible for rising obesity rates? The answers are not at all simple. In humans it is difficult to separate the effects of fat from other features of modernization: sedentary lifestyles, abundance of cheap food, the appeal of sweet, highly-processed foods, and the role of advertising in promoting overeating. Further, genetics clearly plays a role, especially the "thrifty genotype." Animal research reveals individual and strain differences in response to high-fat diets.
Health problems related to low dietary fat also are beginning to surface. Low-fat diets lower the "good" HDL cholesterol levels. There are concerns about the lack of essential fats; children especially may suffer nutrient deficiencies. Low-fat diets may harm some individuals, benefit others. Ronald Krauss, head of the American Heart Association's nutrition committee, reports findings that one third of people increase their risk of heart disease on a low-fat diet, while one third benefit and another third are unaffected.
Further, lowering fat intake often means lowering diet quality, when people turn to more high-sugar, calorie-dense, low-fiber, highly-processed foods. While trying to lower fat, Americans have increased their daily energy intake by about 200 calories in 5 years.
Adding to the confusion are the health effects of different kinds of fats. New findings about transfatty acids (as in vegetable oils made solid in shortening and margarine) and an overbalance of omega-6 polyunsaturated fats linked to heart disease and breast cancer complicate the once-simple advice to reduce saturated fats.
Should we then decrease some fats, increase others? Or suspend judgment for a time?
Especially interesting and reassuring is Andrew Prentice's research (page 55) suggesting that if people do not overeat, it does not make much difference whether fat is 10 or 80 percent of calories. A high-fat diet, then, may promote obesity only when we overeat.
This supports the position of nutritionists who believe the widespread disruption of normal eating and mealtimes, the high levels of dieting and disordered eating, the overriding of hunger and satiety signals, that have occurred in the last two or three decades, bear some responsibility for increased obesity rates.
What today's consumers seem to need most is a break from the overemphasis on fat. It has diverted them from key health messages, such as the benefits of eating in moderation, balance, and variety, and of eating normally and living actively.
Frances M. Berg,
Healthy Weight Journal Editor
http://www.healthyweight.net/editor.htm#98-4