Atkins-style low carbohydrate diets are more effective for men than women, US researchers say.
The Atkins diet involves cutting down on carbohydrates
A third of the 15 men on the diet lost more than 10lbs with one participant shedding 25lbs while the weight loss among the 13 women was not as dramatic.
The University of Connecticut study, partly funded by the Atkins Foundation, also compared different types of diet.
A low carbohydrate diet was up to three times more effective at losing weight from the trunk area than a low fat one.
About 10m Britons are believed to be following a diet at any one time, a third of them choosing Atkins-style, high-protein regimes.
The Atkins diet involves restricting carbohydrates, such as potatoes, and concentrating on eating meat and other high protein food.
But critics claim it can have consequences such as kidney damage, thin bones and high cholesterol.
During the study, featured in the Nutrition and Metabolism journal, participants followed each diet for 50 days.
Report co-author Jeff Volek, assistant professor of kinesiology at the University of Connecticut, said: "The results of this study demonstrate that short-term carbohydrate diets outperform low fat diets in terms of weight loss and fat loss."
And he added while the difference was clearest for men, women also lost more weight on low carbohydrate diets.
Low fat diet
But previous research has suggested in the long-term there is little difference between the two types of diet.
A study of 132 patients by doctors in Denmark found that people on Atkins-style low carbohydrate diets tended to lose more weight in the first six months.
However, after 12 months, the weight loss was similar, a team from RVA University in Copenhagen said in September.
Dr Ian Banks, president of the Men's Health Forum, said he would not recommend the Atkins diet as it was "too severe".
"Men tend to put weight on around the stomach which is relatively easy to lose so some of the other low carbohydrate diets are effective.
"But if men want to lose weight, they should live balanced lifestyles and that means doing exercise, eating healthily and not just dieting."