The results of a major review of popular diets by the US federal government shows that only traditional moderate-fat, high-carbohydrate diets seem to keep dieters slim. The Agriculture Department study found that any dietthat limits food to about 1,500 calories per day produces short-term weight loss, The Washington Post reported Friday. Those programs that have put more demands on dieters - like those recommended by groups such as the American Heart Association and Weight Watchers - have the best scientific evidence to back up their success rates and health claims. They recommend consuming no more than 30 per cent of calories as fat, limiting protein to about 20 per cent of the diet and consuming more fruits, vegetables and complex carbohydrates to help satisfy hunger with fewer calories. They are the most nutritionally adequate and showed some of the best improvements in blood levels of the dangerous cholesterol and blood fats and in blood sugar control, the study found. The study is to be released publicly on Wednesday, the Post said.