In the study, plates were divided into sections for carbohydrates, proteins, cheese and sauce, and the rest was for fruits and vegetables. The plates provided 800-calorie meals for men and 650-calorie meals for women. Cereal bowls provided 200-calorie portions.

Half of the participants in the study used the plates and bowls, while the other half received advice and assessments from dietitians. At the end of the study, nearly 17 percent of those who used the plates and bowls lost 5 percent of their body weight, while only 4.5 percent of the other participants were able to lose the same amount of weight. Previous research has shown that people who are able to lose 5 percent of their body weight decrease their risk of developing conditions such as heart disease and cancer.

If you don't want to use plates and bowls that delineate your portions for you, you can simply read the labels on food packaging to determine just how big a portion should be. It can be quite surprising sometimes to read a label and find out that the box of food you're holding has eight servings, for example, when all along you thought it was only two.

Source:
Archives of Internal Medicine, 25 June 2007