Low-Fat Diet Does Little to Alter Cholesterol Levels
Such an eating regimen had almost no effect on cholesterol levels, according to a report in the April issue of the American Journal of Clinical Nutrition on the Womens Health Initiative (WHI), a national trial that gave some women intensive training and education on eating a low-fat diet and compared their health with women who didnt change their eating habits.
The best that study author Barbara V. Howard, a professor of medicine at Georgetown University, could say for a low-fat diet was that it didnt make things worse as far as affecting blood levels of good fats, such as HDL cholesterol, and bad fats, such as triglycerides.
quot;This diet did not raise triglycerides and didnt lower HDL cholesterol,quot; Howard said. quot;It didnt do any of the adverse things that high-fat people have claimed.quot;
In addition, women who lowered intake of specific kinds of fats -- saturated fats and trans fatty acids -- did have lower a lower rate of heart disease, she said.
And eating a low-fat diet might make it easier to lose weight, which is important because of the current American epidemic of obesity, Howard noted.
quot;If you start out eating too many calories and you cut fat, that automatically makes you eat a higher-carbohydrate diet,quot; she said. quot;If a person wants to reduce weight and is comfortable with cutting fat, that is a good strategy.quot;
Begun in 1991, the WHI was initially designed to determine the effect of a low-fat diet on cancer risk, with heart disease reduction a secondary goal. In 2006, the first results showed there was no effect on cancer risk.
In the trial, women who followed the low-fat regimen consumed 29.3 percent of their calories as fat, compared with 37 percent of those in the comparison group. But the low-fat diet did not affect blood triglyceride, HDL cholesterol or other lipoprotein levels.
quot;The main message here is that if you want to lose weight and cut fat to do it, you do not have adverse effects,quot; Howard said. Though the choice of diet can be influenced by many factors, including cultural background, quot;in my opinion, if you have to cut calories to lose weight, it is easier to cut fat because fat is denser,quot; she said.
So a recommended diet would quot;focus on vegetables, grains, healthy products that are not calorie-dense and that can fill you up more easily,quot; she said.
But Howards advice to switch to a high-carbohydrate diet is disputed by Jeff. S. Volek, an associate professor of kinesiology at the University of Connecticut and an expert in the field.
The study quot;does hint at the fact that people with insulin resistance, as shown by high triglycerides or being diabetic, tend to do worse when carbohydrates are increased,quot; Volek said. quot;Decreasing carbohydrates represents the preferred approach for people with insulin resistance.quot;
In the end, Volek said, quot;its difficult to make any firm conclusions from a study like Womens Health Initiative because, after years of being prescribed a diet, very few people are actually on the diet.quot; Self-reports of food intake quot;are notoriously inaccurate,quot; he said, and quot;even though the number of subjects is large, the noise is even greater so that these studies contribute very little to actual knowledge on the interaction of diet and health.quot;
quot;There is a distinct difference,quot; he pointed out, quot;in studying what happens when you assign a diet vs. what happens when people actually follow a diet.
(HealthDay News)