Thursday, June 18, 2009

Weight Loss Is More About Less Calories And Exercise

I just ran across some interesting information from a new study sponsored by the NIH. The conclusion was that any heart healthy diet that cuts calories can help overweight and obese adults achieve and maintain weight loss. This is no matter how you count the proportions of fat, protein or carbohydrates.

Researchers funded by NIH’s National Heart, Lung and Blood Institute (NHLBI) used 811 overweight and obese adults, aged 30 to 70, and assigned them to 1 of 4 diets. The participants didn’t have diabetes or severe heart disease but may have had other risk factors like high blood pressure or cholesterol.

The 4 diets all had the same calorie reduction goals and were heart-healthy, (low in saturated fat and cholesterol and high in fiber). They varied the levels of fat, protein and carbohydrates. The 4 diets were: 1) low-fat (20% of calories), average protein (15% of calories); 2) low-fat, high-protein (25% of calories); 3) high-fat (40% of calories), average protein; and 4) high-fat, high-protein. Carbohydrates ranged from 35% to 65% of calories.

The participants recorded their food intake for 2 years, had diet counseling sessions, and were also asked to do moderate-intensity physical activity like brisk walking, for at least 90 minutes per week.

The report was published by the researchers on February 26, 2009, in the New England Journal of Medicine.

They saw about the same weight loss in all 4 diet groups after 6 months and also after 2 years. On average, participants lost 13 pounds at 6 months and maintained a 9 pound loss at 2 years. The participants also reduced their waistlines by 1 to 3 inches by the end of the study. Craving, fullness, hunger and diet satisfaction were similar across the 4 diets.

Other studies showed that a loss of 5-10% of body weight will help reduce risk factors for heart disease and other medical conditions. In this study, 15% of patients achieved a 10% weight loss after 2 years. Consistent with previous studies, the diets all improved several known risk factors for cardiovascular disease.

"This new information should focus weight loss approaches on reducing calorie intake rather than any particular proportions of fat, protein or carbohydrate," says principal investigator Dr. Frank M. Sacks of the Harvard School of Public Health.

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