Washington Center for Weight Management and Research Inc.

Introduction to Volumetrics
By Kathy McFalls, MS, RD, LD

If you tended to eat the same amount of food at each meal to feel full, what do you think would be the best type of food to lose weight? (Hint: there may be more than one answer.)

a) Grains, like pasta and rice
b) Fruits, like berries, melon, grapes, bananas
c) Fats, like olive oil, nuts, butter, condiments
d) Meats, such as beef, pork, chicken, fish
e) Vegetables, such as corn, green beans, spinach, broccoli, or salad fixins’
f) Dairy, like milk, yogurt, cheese

This is not a trick question. Research shows that individuals on average eat the same weight or volume of food over a 1 or 2 day period. In fact, the weight of food individuals eat is more similar than the calories they consume from day to day. Why is this? We have learned that a certain portion size of food will satisfy us and we perceive that larger portions will be more satisfying regardless of the calorie content. This is a significant finding. Let’s suppose it takes a pound of food to make you feel full, the type of food will have a significant impact on your calorie intake and body weight. Eating a pound of nuts will pack in 2,800 calories, whereas a pound of fresh apple slices will easily fill you up on a mere 220 calories –that’s one pound!

Which of these 200 calorie portions would fill you up?

200-calories of sliced apple or 200-calories of mixed nuts

Dr. Barbara Rolls, a nutrition researcher at Penn State, has investigated the relationship between volume, calorie density and satiety. She believes that the missing ingredient in most weight loss programs is satiety. Satiety is the sense of fullness at the end of a meal. Achieving satiety is critical in managing hunger when you are trying to lose weight. In one study, Dr. Rolls served a group of women 3 meals over a 2-day period. The women were given 3 different pasta dishes containing the same ingredients, but having different calorie content – a low calorie dish, a medium calorie dish & a high calorie dish. The surprising results, the women ate the same amount of food by weight regardless of the calorie level. Consequently, when the women ate the lower calorie dish they consumed 30% fewer calories compared to when they had the higher calorie dish. On average, this was a 400 calorie difference. That’s not all! They reported being equally full and satisfied despite the lower calorie intake.

One strategy to help you lose weight is to eat a higher volume or weight of food at a lower calorie density. How do you achieve a high volume, lower calorie diet? Here are a few strategies that I will be discussing in my class series on Volumetrics.

1. Include foods with high water content at every meal and snack, such as fruits, vegetables, soups, salads or non-fat dairy.

2. Reduce the fat used in cooking and replace with low energy dense foods. One tablespoon of butter or oil is 100 calories which is the equivalent of 2 cups of vegetables.

3. Use fatty condiments sparingly, or replace with lower fat (“light”) versions, such as light mayonnaise, light salad dressings, light margarine, low fat sour cream & cream cheese.

4. Choose foods high in fiber, such as whole grains, fruits, vegetables and legumes. Fiber is the indigestible part of plant foods; it takes longer to chew and slows passage of food through the intestinal track which aids in fullness and satiety.

5. Baked snacks such as pretzels, chips or crackers are only slightly lower in calories (& therefore calorie density) than their fried versions. Make a compromise— eat less of the snack and supplement with grape tomatoes or sliced apples or any of your favorite fruits or veggies.

6. Replace whole dairy with non-fat or low-fat dairy foods. The high protein content of milk and yogurt also provide satiety. Replacing a cup of full-fat yogurt with non-fat yogurt will allow you to add 1 cup of berries or 2 cups of melon and the calories remain the same while the volume doubles.

7. Include adequate amounts of lean meat and high protein meat alternatives, for example 6 ounces of lean fish are the same calories as only 3 ounces of many cuts of red meat. In casseroles or chili, cut the amount of meat by half. In some recipes this could cut the calories by 800 and then add peppers, carrots & zucchini.

8. Odd-shaped food gives the appearance of more volume on your plate. For example, 1cup ziti will not be as compact as 1cup risotto. When food gives the appearance of more volume, we anticipate being more satisfied—and believe it or not, studies show we are!

For more detail, check-out The Volumetrics Eating Plan by Dr. Barbara Rolls, PhD or come to my classes.