All Other Things Being Equal, Have Some Fruit

I recommend that my patients eat fruit for snacks because they're delicious and have lots of fiber, so they're satisfying. They're also low energy density foods: they have comparatively few calories for their weight. This idea of energy density is really important to keep in mind when you're trying to lose weight, because you can eat more of a low-energy-density food and still eat the same number of calories as those in a high-energy-density food like cookies or potato chips.

On the other hand, weight loss is basically burning more calories than you consume. So you'd think that it wouldn't matter what, exactly, you eat, as long as you eat fewer calories than you burn. Right?

Maybe not. A small study recently appearing in the journal Appetite (2008;51(2):291-295) examines the effects of three different snacks on weight loss. Thirty-four overweight and otherwise healthy women received counseling from a dietitian on following a reduced-calorie diet. For two weeks the participants followed their low-calorie diet, then were randomly assigned to receive one of three types of snacks: either apples, pears, or oatmeal cookies.

The oatmeal cookies were created specifically to contain about the same number of calories as the apples or pears, and also contained about the same amount of fiber. The oatmeal cookies were, however, more energy-dense than the apples or pears.

Each subject was instructed to eat three of their assigned foods each day as snacks: between meals and as dessert. Their basic low-calorie diet was adjusted to allow for the addition of the snacks, so that the participants continued to eat the same number of calories each day, regardless of what their assigned snacks were.

After ten weeks of following a reduced-calorie diet with their assigned snacks, those women eating fruit as snacks lost weight (an average of 2 pounds), while those women eating cookies actually gained a small amount of weight (about a pound, on average). This was true despite the fact that the number of calories all of the women ate were the appropriate amount for weight loss.

What this means for you

This is a small study and merits followup, but it's extremely interesting that lower-density foods seem to help with weight loss even when the number of calories eaten stay the same. Make fresh fruit your snack of choice!

First posted: February 4, 2009