In the past decade, technology for modifying the fat content of foods has progressed and led to the development of highly palatable low-fat foods. Many Americans believe that weight loss can be accomplished by eating an ad libitum low-fat diet, and the development of highly palatable foods that are low in fat provides welcome additions to the food supply. However, in order to maintain high palatability, some of these foods have added sugars and other energy-bearing substances resulting in some low-fat foods which remain high in energy content and are energy-dense. Using such products as substitutes for higher-fat versions of foods is likely to bring about only small reductions in energy intake. A better strategy to reduce energy intake is to consume a low-fat diet made up of low-energy density foods such as fruits, vegetables, and other foods high in fiber and complex carbohydrates. Such a diet may include fat-replaced foods which are also reduced in energy since, for weight loss, a sustained reduction in energy intake is necessary. This can be best accomplished by eating a balanced diet not only low in fat content but also lower in energy.