Provision of foods differing in energy density affects long-term weight loss

The energy density (kilocalories per gram) of foods influences short-term energy intake. This 1-year clinical trial tested the effect on weight loss of a diet incorporating one or two servings per day of foods equal in energy but differing in energy density.

Dietitians instructed 200 overweight and obese women and men to follow an exchange-based energy-restricted diet. Additionally, subjects were randomized to consume daily either one or two servings of low energy-dense soup, two servings of high energy-dense snack foods, or no special food (comparison group).

All four groups showed significant weight loss at 6 months that was well maintained at 12 months. The magnitude of weight loss, however, differed by group (p=0.006). At 1 year, weight loss in the comparison (8.1+/-1.1 kg) and two-soup (7.2+/-0.9 kg) groups was significantly greater than that in the two-snack group (4.8+/-0.7 kg); weight loss in the one-soup group (6.1+/-1.1 kg) did not differ significantly from other groups. Weight loss was significantly correlated with the decrease in dietary energy density from baseline at 1 and 2 months (p=0.0001) but not at 6 and 12 months.

On an energy-restricted diet, consuming two servings of low energy-dense soup daily led to 50% greater weight loss than consuming the same amount of energy as high energy-dense snack food. Regularly consuming foods that are low in energy density can be an effective strategy for weight management.