Most people cannot stick to a diet, because of the hunger it causes: how the heck can you detain, when you have already lost your minds due to your empty stomach? That's why a new research shows how smart eating, not less food, is the secret for losing weight.

A year-long clinical trial made by a Penn State team revealed that diets based on foods that are low in calorie density are the most effective in losing weight as they do not torture people because of hunger.

Foods rich in water and low in fat, like fruits, vegetables, soup, lean meat, and low-fat dairy products, are also low in calorie density while offering few calories per bite.

"Eating a diet that is low in calorie density allows people to eat satisfying portions of food, and this may decrease feelings of hunger and deprivation while reducing calories" said Dr. Julia A. Ello-Martin, from the College of Health and Human Development at Penn State.

"Such diets are known to reduce the intake of calories in the short term, but their role in promoting weight loss over the long term was not clear," said lead researcher Dr. Barbara J. Rolls, holder of Helen A. Guthrie Chair of Nutritional Sciences at Penn State.

"We have now shown that choosing foods that are low in calorie density helps in losing weight, without the restrictive messages of other weight loss diets," explained Ello-Martin.

The team compared two diets: one made of fat-low food items and another made of fat-low but water-rich foods items, in a pool of 71 obese women aged 22 to 60.

Unlike in most diets, the subjects were permitted to eat how much they wanted to.
After one year, the subjects in both groups displayed visible weight loss as well as a drop in the calorie density of their diets.
But those who followed the diet based on water-rich food items lost during the first six months of the research 19.6 pounds (9 kg) compared to 14.7 pounds (6.7 kg) for the other category.

The weight loss was easily maintained in both groups during the second six months of the trial. The subjects that ate water-rich foods consumed 25 % more food by weight and experienced less hunger than women on the other diet.

"By eating more fruits and vegetables they were able to eat more food, and this probably helped them to stick to their diet and lose more weight," said Ello-Martin.