Q. How can I lose weight when eating less makes me hungry?

A. You don't need to eat less food to lose weight. You can eat plenty of food, if you choose foods that take up lots of space in your 'opu without providing lots of calories.

Penn State University nutritionist Barbara Rolls has studied amounts of various foods people need to satisfy their hunger. Her book "The Volumetrics Weight-Control Plan" (HarperTorch, 2003) offers practical advice on losing weight without feeling hungry.

According to Rolls' research, calories in a given volume of food influence how many calories people consume at a meal, and throughout the day. We eat roughly the same amount of food daily regardless of the calories. By choosing foods that offer fewer calories for the same amount of food, we can manage our weight without hunger.

Nutritionists call this "energy density." High-energy density means a food has lots of calories in a small portion. For example, a handful of chips has 130 calories. That's a lot of calories for such a small amount of food.

The more calories that are packed into a given weight or volume of food, the easier it is to overeat. When eating an energy-dense food such as chips, people tend to eat more calories because a small portion seems like too little food. Who can stop at just one handful?

Generally, foods containing lots of water have lower energy density. These include fresh fruits, vegetables, nonfat milk and broth-based soups. For 100 calories you could eat one cup of seedless grapes or 1/4 cup of raisins. Since raisins, don't have water, they take up less space in your stomach than the grapes. This makes them less filling and may increase your desire to eat a larger portion, resulting in more calories.

Consider starting your meal with a broth-based soup or salad. In a recent study, those served a low-calorie soup or salad before their meal ate fewer calories during the meal than those who started with a heavy pupu or no appetizer at all.

Fiber in beans, whole grains, fruits and vegetables also increase food volume. In addition, fiber holds water in the digestive tract, contributing to a lasting sense of fullness.

Fill your stomach with low-calorie foods and your portions of other foods will automatically become smaller. You won't even feel deprived!

Amy Tousman is a registered dietitian and certified diabetes educator. Hawai'i experts in traditional medicine, naturopathic medicine and diet take turns writing the Prescriptions column. Send your questions to Prescriptions, Island Life, The Advertiser, P.O. Box 3110, Honolulu, HI 96802; fax 535-8170; or e-mail islandlife@honoluluadvertiser.com. This column is not intended to provide medical advice.