Jeff Volek and colleagues, from the University of Connecticut, also show for the first time that a low carbohydrate diet is much more effective in losing fat from the stomach and chest. Upper body fat carries "a greater health risk than fat stored in other regions of the body," say the authors. They found that fat loss in men was three-times greater in the trunk area, when they were on a low-carbohydrate regime compared to the low-fat diet. Nearly all participants in the study (12 of 15 men and 12 of 13 women) lost more fat on their upper body on the low- carbohydrate diet.
Fifteen overweight or obese men, and thirteen women, were randomly assigned to a very low carbohydrate diet or a low fat diet. After fifty days, they were switched to the other diet. 11 of the 15 men did better on the low carbohydrate diet, six lost greater than 10 lbs more on the low carbohydrate diet, and one subject lost almost 25 pounds more. Similar results were found for women although the results were less dramatic.
Volek and colleagues also looked at whether weight and fat loss were affected by what order the diets were done in. Their data seem to favour undertaking a low carbohydrate first, suggesting that those who have concerns about long term 'low carb' diets could follow a low carb diet first followed by a low fat diet.
There is much debate about the health implications of long-term use of low carbohydrate diets. Volek's lab, whose work is the first-ever to be funded in part by the Robert C. Atkins Foundation, has previously shown that low carbohydrate diets improve cardiovascular risk factors.