High-carbohydrate, high-protein, high-fat—regardless of which of these three macronutrients is emphasized in a diet, the person will lose weight as long as calories are being reduced. This was the conclusion drawn by a team of researchers led by Frank M. Sachs, MD, of the Harvard School of Public Health in Boston (N Engl J Med. 2009;360:859-873).
The two-year study funded by the National Heart, Lung, and Blood Institute assigned 811 overweight adults to one of four diets with various balances of carbohydrate, protein, and fat. The regimens amounted to at least 1,200 heart-healthy calories per day.
Weight loss was similar across the groups, with 14%-15% of participants losing at least 10% of their baseline body weight. (Average weight loss at study’s end was 9 lb.) All the interventions improved lipid-related risk factors and fasting insulin levels.
Whatever diet for weight loss is followed, clinicians should remind patients to watch their sodium intake. The CDC recently announced that more than 70% of U.S. adults are overdoing it in terms of sodium intake. The recommended daily goal of <1,500 mg is stricter than the <2,300 mg/day limit of sodium (approximately 1 teaspoon of salt) put forth by the 2005 Dietary Guidelines for Americans.
Kirsten Bibbins-Domingo, PhD, MD, assistant professor in residence at the University of California at San Francisco School of Medicine, estimated that 250,000 fewer new cases of heart disease and more than 200,000 fewer deaths would occur over the course of a decade for every 1-g reduction in daily salt intake among Americans. She presented her findings at the American Heart Association’s 49th Cardiovascular Disease Epidemiology and Prevention Conference 2009 in Palm Harbor, Fla.