One of the longer clinical trials to compare a low-carb diet with a low-fat, low-calorie weight-loss regimen reports that both were effective for losing weight-but the low-carb diet also delivered a heart-health bonus.Previous studies have shown that low-carbohydrate diets can jump-start weight loss, but long-term results have been mixed. So Gary D. Foster, PhD, of Temple University, and col-leagues randomly assigned 307 overweight and obese partici-pants to either a low-carb or a low-fat, calorie-restricted diet and followed their progress for two years. Initially, partici-pants weighed an average of 227 pounds and had a mean body mass index (BMI) of 36.Those assigned to the low-carb plan could eat as much fat and protein as they wanted, and had no set calorie goal. They focused on cutting down on carbohydrates, to 20 grams per day for the first 12 weeks and increasing by 5 grams daily per week thereafter. The low-fat group limited calories to 1,200-1,500 daily for women and 1,500-1,800 a day for men; car-bohydrates accounted for about 55% of their calorie intake, fat 30% and protein 15%.After one year, both diets had led to a similar average weight loss of 24 pounds. As is typical with weight-loss plans, however, participants put back on some pounds, winding up with an average loss of 15 pounds after two years.Foster and colleagues concluded in Annals of Internal Medicine, Both diet groups achieved clinically significant and nearly identical weight loss. These long-term data suggest that a low-carbohydrate approach is a viable option for obesity treatment for obese adults.But those on the low-carb regimen also saw some addi-tional benefits for heart health. They experienced more rapid early improvement in blood pressure, triglycerides and VLDL cholesterol. Although those differences evened out after two years, the low-carb group showed greater increases in HDL (good) cholesterol throughout the study, ending up 23% versus 12%.For a diet, thats pretty impressive, Foster said, likening the HDL changes for the low-carb group to improvements typically seen from a drug intervention.After two years, low-carb dieters also had small but statis-tically relevant greater reductions in total cholesterol.The findings, Foster commented, should allay concerns that low-carb, Atkins-style diets might boost the risk of heart disease because of their higher levels of fat.Other recent research suggests whats really important in low-carb diets is what you eat instead of carbohydrates, with vegetable protein a better choice than meat. See the next Healthletter for details.TO LEARN MORE: Annals of Internal Medicine, August 3, 2010; abstract atwww.annals.org/content/153/3/147.abstract
