Volumetrics is an approach to eating that helps satisfy hunger with fewer calories.

The term Volumetrics is used by Barbara Rolls, Ph.D., Guthrie Chair of Nutrition at Penn State and former president of the North American Association for the Study of Obesity, and award-winning journalist Robert A. Barnett in their book, Volumetrics: Feel Full on Fewer Calories. (NOTE: The paperback edition is titled The Volumetrics Weight-Control Plan: Feel Full on Fewer Calories.)

Can the Volumetrics way of eating help you? Here's an interview with Dr. Rolls to help you learn more about Volumetrics so you can decide for yourself. There also are two Volumetric-type recipes for you to enjoy.

First, though, a few comments -- based on the interview with Dr. Rolls -- about what Volumetrics IS NOT.

What Volumetrics Is Not

Sometimes it's easier to understand a new concept such as Volumetrics by first learning what it IS NOT. Here's an overview of Dr. Rolls' points on what Volumetrics IS NOT:

• Volumetrics IS NOT a stuff-your-stomach-with-celery-and-water eating plan. The Volumetrics approach enhances sound nutrition and, according to Dr. Rolls, is consistent with and supports the dietary recommendations of the:
  • Healthy People 2010 (Health Objectives)
    www.health.gov/healthypeople

     

• "Volumetrics IS NOT a gimmick for rapid weight loss," says Dr. Rolls. Nor is it just for people trying to lose weight. If a person is at an unhealthy weight, eating the Volumetrics way can help with weight loss, she said. If a person is at a healthy weight, Volumetrics can help maintain that weight.

An Interview With Dr. Rolls

NOTE: The following is provided as information for general healthy eating. It should not be considered a substitute for seeking dietary advice from your own health care provider.

Food Reflections: What is Volumetrics and how does it help control weight?

Dr. Rolls: Volumetrics is a weight management plan based on research related to satiety. It's about how different foods affect hunger and how full you feel.

Volumetrics gets you thinking about the volume or portion size of foods you need to eat to feel satisfied. Many people feel they have to eat little tiny portions to lose weight or to maintain their weight at an acceptable level. But, when they do that, they feel hungry.

A core concept of the book is the amount of calories in a given weight of food (calories per gram) or the "energy density." When left to their own devices, people choose a fairly constant portion of foods from day to day. Volumetrics is based on maintaining the usual amount of food you eat yet lowering the calories in each portion so you can consume fewer calories yet feel just as full.

Fat raises the energy density of foods but water is also important because it adds weight and volume but no calories. That's why fruits and vegetables, which are high in water, are the main players. Volumetrics really leads you to the foods you should be eating anyway and explains how they can help control our caloric intake. Soup can also play an important role in helping with satiety -- we include a whole chapter on soup in the book.

The volume is important as well as the energy density. In general, portions that weigh more are bigger in volume. We experimented with strawberry smoothies in our lab and added different amounts of air, simply affecting the volume and not the weight or energy density. We found that the bigger the smoothie that people drank a half-hour before lunch, the less they ate at lunch. They also didn't make up for the calories later in the day. My student, Dr. Elizabeth Bell, reported a study recently at the annual meeting of the North American Association for the Study of Obesity that indicates that foods that look bigger in volume and with irregular shapes that fill the bowl more also can affect satiety.

Water, though, is a bigger player than air. There are a lot more ways you can add water or water-rich fruits and vegetables to foods than there are things you can do with air.

Food Reflections: You mentioned several nutritional factors in your book that affect the energy density of foods and how well the foods will satisfy hunger. Fat, fiber and water were cited as having some of the greatest influence. Would you comment briefly on these? Can a person just drink large amounts of water to satisfy hunger?

Dr. Rolls: A number of labs are plotting out the influence of different elements of foods on energy density. Water has the most influence, then fat. But, fat's influence isn't as great as that of water. A gram of fiber and a gram of water can have the same influence, but there's a limit to how much fiber you can add or you'll get a pretty big gastrointestinal disturbance. The upper range for fiber is somewhere around 30 grams though some people might be able to go higher. You can add 500 grams of water easily and that's going to have a much bigger impact. When you do add fiber, it's best to get it from food.

I've heard anecdotal stories about how drinking water could influence satiety. However, I haven't found any systematic data in the scientific literature that shows that drinking lots of water controls hunger or has any impact on weight loss. In our studies, drinking water didn't have an impact, but incorporating the water into the food (i.e. eating water-rich foods like soup, pasta with vegetables, etc.) did have an impact on satiety and food intake.

One challenge when talking about liquids is: When is a liquid considered a food and when is it considered a drink? Various liquids are processed by different mechanisms in the body. The hunger and thirst mechanisms are quite separate. A soft drink will trigger thirst mechanisms, not hunger mechanisms, and add calories without satisfying hunger. You may end up consuming more total calories than if you didn't take the drink.

Milk-based drinks and drinks with some protein will influence hunger mechanisms. In our lab, we found that milk-based drinks help people feel full and eat less at the next meal.

I think a lot of people take in way too many calories from sugar-sweetened beverages. I tell people that if they're trying to lose weight, in some degree they're lucky if they're getting a lot of calories from soft drinks because it's an easy habit to change. There are a lot of good substitutes for caloric soft drinks. It's a pretty easy way to reduce your calorie intake.

It's much better in terms of satiety to eat whole fruit, which has more fiber and offers more satisfaction in chewing, than fruit juice. There have been studies done that show you will feel more satiated with whole fruit than juice.

If you're thirsty, water is the best choice for quenching thirst, followed by calorie-free or low-calorie beverages.

Food Reflections: In your book, you state that the Volumetrics approach is consistent with the Food Guide Pyramid. What are some food choices from each Pyramid food group that would make meals more Volumetric and help a person concerned with weight management? What about beverages and soups? (NOTE: Readers will learn in the answer to a later question how you don't have to AVOID any foods in a Volumetrics-based eating plan.)

Dr. Rolls: Some types of foods that would make meals more Volumetric include:

• Bread, Cereal, Rice and Pasta. You would choose foods that have more fiber, complex carbohydrates and water. You would want less of the dry crackers, pretzels and so on; they're very easy to overeat. Go for such foods such as high fiber breakfast cereals, higher fiber content breads. These are the most nutritious choices, anyway. Go for your brown rice rather than white rice.

  Anytime you can choose a food that has a higher fiber content and a higher water content, that's the better choice.

   

• Fruits and Vegetables. Almost all foods from this group can be eaten in unlimited quantities. Go for the hydrated ones rather than dry ones so you get more satiety, grapes rather than raisins. Make good varied choices. Find ones you really enjoy so you find an eating pattern you stick to because you like the foods you're choosing.

  We suggest people try new fruits and vegetables. Try cooking them different ways so you can maintain your interest. Most people are not eating enough from these two groups. Many people are getting a big hunk of their vegetable group from French fries. Cut back on eating fried vegetables and save the fat for healthy nuts or a piece of chocolate rather than drenching your veggies in fat.

   

• Milk, Yogurt and Cheese. Go for the lower fat versions. For example, if you choose skim milk over whole milk, you get a portion that's twice as big for the calories. Or, if you had the same portion, you'd take in half the calories. Also, you get less saturated fat so it's not a bad thing to go for the lower fat versions as that's not a healthy kind of fat.

   

• Meat, Poultry, Fish, Legumes, Eggs and Nuts. Choose lower fat forms. For example, include leaner meats, poultry without skin and baked fish. Small portions of nuts give good healthy fats.

   

• Soup. We've done a lot of studies with soup. Soup gives a lot of satiety. Obviously if you had a really high-fat soup, you could end up taking in too many calories. So you want to go for your broth-based (such as vegetable with beef broth soup or chicken, rice and vegetable soup) and tomato-based soups. For example, if you wanted a clam chowder, you would go for the Manhattan rather than the New England because it's going to be tomato-based rather than cream-based.

  If you're going to have soup as a first course, go for a satisfying portion with 100 calories or less. Again, you could end up overeating if you have a whole lot of calories at an additional first course. Again, if you're going to have soup as a snack, you'd probably want one with 100 calories or less. There are a lot of commercially available soups that have 100 calories or less in a portion. It's a pretty easy strategy as a nice convenient snack or first course that can help control hunger.

  I think often for snacks, people only need 100 calories to help control hunger. Only they're reaching for a candy bar or a bag of chips that in a small amount may be giving them more calories than they need. And it's not in a very big portion so it's not very satisfying.

   

• Condiments, Salad Dressings and Sauces. Find non-fat and low-fat ones you like. For example, when people are trying to decide on a salad dressing, some people will like fat-free dressings. Others will like reduced-fat versions. Others may really want their olive oil and vinegar and they can make that choice; they just need to take less of it. People have to decide their own pattern, but they need to be aware that if they go for the high-fat version, they get much less as a portion. Some fat is necessary in the diet to provide essential nutrients.

   

• Desserts: If you want to have dessert, ones that have some fruit in them to help dilute calories are a good choice. Having a piece of chocolate at the end of a meal is really not a bad strategy. You're already pretty full and less likely to overeat and sit down and eat the whole box. I find myself that having the most delicious chocolate I can think of in a small amount at the end of the meal really helps me end the meal! It's a satisfying finish and I know I'm finished then. You need to keep the sensory pleasure in there, too.

   

• Candies. If you need something sweet, have a hard candy. You can use candy in small doses to satisfy the desire for something sweet! You don't have to eat the whole bag, one hard candy might do it.

   

Dr. Rolls: No, we did one study where we measured how much lean and overweight women normally ate. Then for four days in a row, they ate all their meals in our Eating Lab. They were REQUIRED to eat the entire portion of main dishes that provided half the calories they normally ate at that meal. Then, they could eat anything they wanted for their other foods and between meals.

We established the amount of food people normally ate and then in random order tested them all in all conditions so they got both high and low energy density foods after their baseline intake was determined. When we lowered the energy density of the required main dishes, they didn't eat any more of the "free" foods offered at and between meals. The women weren't consciously dieting; however, they spontaneously ate about 100 calories less a day and felt just as full and satisfied. Both overweight and lean women responded similarly to the reduction in energy density.

In another study, we served a chicken, rice and vegetable soup before lunch. The women reduced the calories they consumed from other foods at lunch.

I think this indicates you don't have to change your entire diet. You can start by changing some of the foods you're eating and you're going to feel fuller on those foods and you're going to eat less of the foods that are higher in energy density. Obviously, the more you can change, the more likely it is to work. Just changing a few foods, like choosing reduced-fat potato chips over full-fat potato chips, probably won't do enough.

The types of foods you need to eat aren't extreme and can be used for just weight maintenance as well as weight loss. Unless people are cutting calories dramatically, there's no reason for any risk in following a Volumetrics way of eating. It's compatible with the Dietary Guidelines. What they're doing is getting their calorie intake down to a more reasonable level.

Food Reflections: How can a person lower the energy density of higher energy dense foods and make them more suitable for a Volumetrics eating plan?

Dr. Rolls: Any time you can add vegetables to your favorite dish, you'll dilute down the energy density. Use your favorite vegetables. For example, if you can substitute your favorite veggies for some or all of the pepperoni on your pizza, you're really going to reduce the energy density quite dramatically.

Food Reflections: Are there any other tips you'd like to give readers who would like to try eating the Volumetrics way?

Dr. Rolls: We suggest that for a few days people keep track of what they're eating. I think people need to identify where the problem foods might be so they know which ones they can tweak to lower the energy density. For example, if someone finds they are getting an enormous amount of calories from the fat in salad dressing, they need to identify that early on so they know where they need to make some changes. I wouldn't recommend people keep track of calories for the rest of their lives. But I do think it can be useful because I think a lot of people are not aware that they may be taking 500 calories a day from soda for example. I think that is a good way to start.

Then, they need to play with it when they know how to reduce the calories and the portions. They need to experiment with their own eating pattern and that of their families so they find ways to still enjoy foods. In our lab, we reduce the energy density easily by 30 percent and people can't even tell the difference. It may take some playing with seasonings if people are actually cooking this way. I want them to find a pattern they enjoy and can stick with. I can't emphasize that enough. This isn't a gimmick for rapid weight loss. It's really a way to try and get people to eat healthy.

Roland Weinsier, at the University of Alabama in Birmingham, has used this kind of plan for 25 years in his program. He has published some studies on weight maintenance and has found excellent success in keeping weight off. The people actually change their eating patterns so they're eating more fruits and vegetables, eating more satisfying portions of foods and not overindulging in the high-fat foods. It just becomes their preferred way of eating. And that's what we want them to do. Because if you're going to maintain the weight loss, that's what you have to achieve. You have to just automatically eat this way.

Volumetrics Recipes

To help readers enjoy Volumetrics types of foods, the book includes several recipes developed by Debby Maugans Nakos of Southern Food Consultants in Birmingham, Alabama. Here are two of these recipes for your eating pleasure.

Corn Chowder
This makes a comforting first course, or, with the addition of chicken or salmon, the centerpiece of dinner.

3 cups canned low-fat or fat-free chicken broth

2 3/4 cups (16 ounces) lightly packed frozen hash brown potatoes, thawed

1 (10 ounce) package frozen whole kernel corn

1 cup chopped onion

1 cup chopped green pepper

1/2 cup finely chopped celery

1/2 teaspoon dried thyme

1 1/2 cups low-fat (1 percent) milk

2 tablespoons all-purpose flour

1/2 teaspoon salt

1/4 teaspoon ground red pepper

Using a slotted spoon, transfer 2 1/2 cups of the vegetable mixture to a food processor or blender. Process until smooth. Add the milk, flour, salt, and red pepper; process until blended. Add to the remaining vegetables in saucepan. Cook over medium heat until the soup is thick and bubbly, stirring frequently.

Serve immediately, or store in covered containers in refrigerator for up to 3 days, or in the freezer for up to 1 month.

Yield: 8 servings of 1 cup each.

Nutritional Information Per Serving. Calories: 140. Energy Density: 0.6. Carbohydrate: 27 g. Fat: 1 g. Protein: 6 g. Fiber: 3 g. Sodium: 416 mg. Good Source: Vitamin C.

Main Dish Variation. For each serving, add 3 ounces (about 2/3 cup) chopped cooked chicken breast (or white meat) or flaked canned salmon. This will increase the serving size to 2 cups. With chicken. Calories: 275. With salmon. Calories: 260.

Reproduced with permission from Rolls, B. J. and Barnett, R. A. Volumetrics: Feel Full on Fewer Calories. HarperCollins Publishers, 2000.

Apple Crumble
A Volumetric apple brown Betty.

6 cups peeled, thinly sliced Granny Smith apples (about 4 large)

3/4 cup firmly packed light brown sugar, divided

2 tablespoons water

3 tablespoons thawed frozen apple juice concentrate, divided

2 teaspoons cornstarch

3/4 teaspoon ground cinnamon

2/3 cup regular oats, lightly toasted*

1/2 cup All Bran with Extra Fiber cereal

1/4 cup whole-wheat flour

1/4 cup all-purpose flour

1 teaspoon ground cinnamon

2 tablespoons canola oil.

Combine the apples, 1/4 cup brown sugar, water, 1 tablespoon apple juice concentrate, cornstarch, and 3/4 teaspoon cinnamon in a large bowl, and toss well to coat the apples. Spoon the mixture into a shallow, 1 1/2 quart baking dish coated with cooking spray.

Combine the oats, flour, cinnamon, the remaining 1/2 cup brown sugar, the remaining 2 tablespoons apple juice concentrate, and the canola oil in a food processor, and pulse until it is just blended. Sprinkle over the apple mixture.

Cover with aluminum foil and bake for 25 minutes.

Uncover and bake for 15 minutes or until the fruit is tender and the topping is crisp. Serve warm or at room temperature.

* (To lightly toast oatmeal:) Preheat the oven to 400 degrees F, spread oatmeal on the baking pan, and bake for 5-8 minutes.

Yield: 6 servings of 3/4 cup each.

Nutritional Information Per Serving. Calories: 245. Energy Density: 1.8. Carbohydrate: 51 g. Fat: 6g. Protein: 3 g. Fiber: 7 g. Sodium: 36 mg. Good Source: Fiber.

Reproduced with permission from Rolls, B. J. and Barnett, R. A. Volumetrics: Feel Full on Fewer Calories. HarperCollins Publishers, 2000.