For their study, researchers at University Hospital in South Manchester in Britain put 115 women volunteers on one of three diets.
The first involved sticking to just 650 calories a day for two days of the week, including cutting out carbohydrates such as pasta, bread and potatoes and all fatty foods. For the other five days they could eat as much as they liked, although they were encouraged to stick to healthy foods.
Women on the second diet were also banned from carbohydrates for two days of the week but they did not have a specific calorie limit. They could also eat as much as they wanted the rest of the week.
The third group followed a standard weight-loss diet which involved sticking to about 1,500 calories every day and avoiding high-fat foods and alcohol, ‘Daily Mail’ reported.
They found that women who stuck to fruit, vegetables and lean meat for two days a week while being allowed to eat as much as they liked on the other days lost nearly twice as much weight than those on the full-time diet, who lost just 2.4 kg.
Dr Michelle Harvie of the Genesis Breast Cancer Prevention Centre at the hospital said there seemed to be a “carry over effect” on the two-day diet, meaning the benefits continued on the days when the women ate normally.
She also said women seemed to continue eating healthily even on the five days when there were no restrictions. “What we found was that they naturally ate less,” she added.