A recent study (funded by the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health) conducted in the recent years has drawn the attention of physicians, dieticians, and individuals to focus on calorie reduction rather than choosing a specific diet to lose weight. Regardless of the kind of diet you choose (carbohydrate, protein, or low fat), you can lose weight if you manage to reduce your calorie intake somehow.
To testify that reducing calorie is the key to losing weight whichever way you achieve it, researchers from the Harvard School of Public Health (HSPH) and Pennington Biomedical Research Center of the Louisiana State University System conducted a randomized clinical trial. Here overweight participants were assigned four different diets for a two-year period and their performance was monitored at the end, where the results revealed that regardless of the choice of the diet, all the four groups could achieve weight loss through calorie reduction. This study appears in the February 26, 2009 issue of The New England Journal of Medicine.
Frank Sacks, lead author of this study and a professor of cardiovascular disease prevention at HSPH, said “This is important information for physicians, dieticians and adults, who should focus weight loss approaches on reducing calorie intake.”
The clinical trial involved 811 men and women who were randomly divided into different diet groups with different nutritional components:
- Low-fat, average protein: 20% of calories from fat, 15% of calories from protein, 65% of calories from carbohydrate
- Low-fat, high-protein: 20% fat, 25% protein, 55% carbohydrate
- High-fat, average protein: 40% fat, 15% protein, 45% carbohydrate
- High-fat, high-protein: 40% fat, 25% protein, 35% carbohydrate
These participants differed largely in terms of age, background, income, and geography. The diets administered to all these participants were carefully chosen to ensure heart-friendly principles; use of unsaturated fat instead of saturated fat; and included whole cereal grains, fruits, and vegetables. Every participant was given an individual prescription that encouraged a calorie reduction of 750 per day. All the participants were made to do 90 minute workout in terms of moderate exercises, which their daily food and drink intake were recorded both in a food diary and in a web-based program to evaluate how closely they meet their dieting targets. In the span of two-years, all these participants were provided counseling session at periodical intervals (in every eight week and three group discussions during the first six months, which got reduced to two discussions after six months till 2 years.)
The results when evaluated after 2 years revealed that all the participants lost an average of 13 pounds at six months and could maintain a 9 pound loss at the end of two years. The efficient weight loss was actually achieved during the first six months and after about a year, all participants started to regain their weight which is normally the case even with other diet studies. Here however the weight gain was much less about 20 % when compared to other studies. Further participants could lose about two inches from their waistline at the end of the two-year timeframe. The main finding of this study, in the words of Elizabeth G. Nabel, M.D., Director, NHLBI, “These results show that, as long as people follow a heart-healthy, reduced-calorie diet, there is more than one nutritional approach to achieving and maintaining a healthy weight.”