Volumetrics Diet Eating Plan

Eat more, but end up weighing less --- that's the idea of the Volumetrics weight-control plan. There's a catch, of course: You have to eat more of the foods that are not so "energy-dense." Volumetrics was developed by Barbara Rolls, a nutrition professor and researcher at Pennsylvania State University. Her approach also includes other elements, such as exercise and portion control, but understanding energy density is the crux of it. As Joan Raymond reported in Newsweek magazine (2007), Volumetrics is supported by peer-reviewed studies and has been catching on with nutritionists as well as dieters.

Volumetrics Basics

In her books, interviews and research reports, Barbara Rolls explains how energy density works. Foods that are energy-dense give you a lot of calories for the volume -- like a thick steak or a sliver of cheesecake. Foods that are less energy-dense, usually because they include more water or air, provide fewer calories for the volume. Examples are most fruits and vegetables, and foods like oatmeal and brown rice that absorb water during cooking. Rolls and her researchers found that a boost in foods with low energy density helps people lose weight by allowing them to eat more and feel more satisfied.

How It Works

Rolls is not one of those diet gurus who wants you to give up all your favorite foods and eat only salads. In "The Volumetrics Weight-Control Plan," she notes that she's fond of chocolate and premium ice cream herself. What she urges you to do is learn to replace some foods that are energy-dense with those that aren't. For instance, you could have about 2 cups of grapes for a 100-calorie snack, but only ¼ cup of raisins, which are more energy-dense. Joan Raymond's Newsweek article notes that Rolls's study, published in the "Journal of the American Dietetic Association " in 2004 found that people who ate 3 cups of salad before a pasta lunch ate 12 percent fewer total calories overall.

Volumetric Foods

Rolls provides lists of ingredients, recipes and even drawings to help you get the hang of Volumetrics. A drawing of a bowlful of pasta salad illustrates that when you use less pasta and more veggies, you can eat almost twice as much for the same calories. She suggests substituting a regular hamburger with a vegetarian burger including bulgur, walnuts, chickpeas, spinach and carrots.

Volumetric Tips

Nutrition labels in some countries include figures on energy density. In the United States, you might need a calculator, but it's not hard: Divide the calories of a serving by its weight in grams, and eat all you want of foods with an energy density less than 1. Often, just adding fruits, vegetables or water will make a food fit into Volumetrics -- like making a fruit smoothie instead of a milkshake or piling veggies onto a pizza rather than fatty meats. But drinking water on the side doesn't have the same effect on appetite. In a Penn State report, Rolls notes that water in food is chemically different than water taken as a beverage as it leaves the stomach more slowly.