Snack Smartly to Fight Weight Gain

Source: Tufts University
December 20, 2002 (Reviewed: December 16, 2004)

Most people round out their three meals a day - breakfast, lunch, and dinner - with a snack or two. In fact, snacking can be an important source of daily nutrients. For some, however, a steady diet of high-fat, high-calorie snacks leads to weight gain. Two recent studies published in the American Journal of Clinical Nutrition examined how and when snacking - and the types of food eaten - affect hunger and satiety.

High carb vs. high protein snacks

In the first study, French researchers examined whether an afternoon snack replaced - or simply added to - calories consumed at dinner. On three separate occasions, a group of 8 healthy men consumed an afternoon snack of a high carbohydrate food (rice pudding), a high protein food (chicken breast) or no snacking. (The rice pudding and the chicken breast were portioned to contain the same number of calories.) The men then ate dinner whenever they were hungry again.

The chicken breast snack seemed to delay hunger the longest, since the men tended to eat dinner about 40 minutes later than they did when snacking on the rice pudding. But the number of calories they consumed at dinner - served buffet style with the volunteers free to help themselves - did not differ. They tended to eat the same amount of food whether or not they had snacked in the afternoon.

Add some fiber and fat

In the second study, University of California researchers looked at how the addition of fiber or fat to a low-fat, low-fiber meal affected satiety. Fifteen men and women received a meal that was either low in fat and fiber, high in fiber and low in fat, or low in fiber and high in fat. The total number of calories of each meal was the same. Blood samples were analyzed to measure chemical changes that occurred during digestion. The volunteers also answered questions to assess hunger and satiety after eating.

The meals that included either fiber (from foods like cereal and dried fruit) or fat (from margarine and eggs) had the most suppressive effect on hunger, the desire to eat, and feelings of fullness. The low-fiber, low-fat meal had the least suppressive effect. The researchers have biochemical proof to back up these findings, since the addition of either fiber or fat to the meal triggered the release of cholecystokinin, a hormone associated with satiety.

Give in to temptation?

These were both small studies and further research is needed to fully understand the role of snacking in weight management and eating habits. But they indicate that satisfaction is important when making food choices. Opting for healthy snack foods -plain, low-fat crackers, for instance - will not help your weight loss efforts if you eventually eat what you really want - cheese and crackers.

Finding healthy snack foods

Weight loss experts recognize that a small portion of a desired food - even if it's high in fat or calories - goes a long way in terms of satisfaction and commitment to healthful eating. And, some types of foods such as high-fiber whole grain cereals, fruits, and vegetables may have 'staying power' and minimize hunger longer than other foods.

Sources

• Plasma cholecystokinin is associated with subjective measures of satiety in women. B. Burton-Freeman, PA. Davis, BO. Schneeman, Amer J Clin Nutr, 2002, vol. 76, pp. 659--667



• Snacks consumed in a nonhungry state have poor satiating efficiency: influence of snack composition on substrate utilization and hunger. C. Marmonier, D. Chapelot, M. Fantino,  et al., Amer J Clin Nutr, 2002, vol. 76, pp. 518--528

Related Links
How to Choose Low-Fat Foods
How to Eat a Healthy Diet
Variety is the Key to a Good Diet
Survey Reveals Gaps in US Eating Habits
Build a Better Sandwich
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