Scientific research shows soup useful tool in calorie control
October 16, 2000 – Americans seeking to control calories should look no further than their next bowl of soup, according to recent dietary research conducted at The Pennsylvania State University. Research results show that people who enjoy a bowl of soup prior to a main course can reduce their caloric intake by as much as 100 calories each day.
“You can’t lose weight without controlling calories, but you can control calories without feeling hungry,” says Dr. Barbara Rolls, Professor of Nutrition at Penn State. Dr. Rolls is the author of a new book, Volumetrics, which provides a sound eating strategy for people trying to reduce their caloric intake. “People don’t have to feel deprived and you don’t have to give up your favorite food,” she adds. Dr. Rolls believes the answer may lie in scientific research that points to soup and other low energy-dense foods as one of the major keys for appetite suppression. Because of its large volume of water, soup adds weight, but relatively few calories, so satisfying portions can be eaten without concern about extra calories.
With more than 50 percent of the U.S. population currently estimated to be overweight, government agencies, including the USDA, have declared obesity a national epidemic. About one third of women and a nearly a quarter of men are trying to lose weight. It is estimated that half of those who do will regain the weight within one year and 75 percent will have regained the weight within three years.1
Campbell Soup Company has taken note of this new research on appetite and trends in obesity and is raising consumer awareness by educating them about their 30 varieties of soup, including such favorites as Minestrone, Vegetable and New England Clam Chowder, which have fewer than 100 calories and 3 grams of fat or less per serving.
“It’s clear that current popular weight loss strategies are failing,” says Dr. Rolls, a 20-year veteran in nutrition research and weight management strategies. Having done extensive research on calorie control, Dr. Rolls says diets should be based on science, not gimmicks. “Most people making an effort to cut calories follow the latest fad diets, rather than the recommendations of nutrition scientists,” she says. “Clearly, we need to be looking at more scientific strategies for weight loss if we are to successfully combat obesity in this country.”
In the case of soup, some scientists believe the ‘secret’ is its inherent ability to signal the body’s “satiety center” and ultimately suppress hunger and control calorie intake. Dr. Rolls’ many years of study further support this thinking. She believes that one of the possible reasons soup is effective in enhancing satiety is because it has a low energy density. Energy density means the number of calories in a fixed portion of food (calories per gram).
Soup as Tool for Calorie Control
In one of Dr. Rolls’ studies, individuals were exposed to one of three different food options through a series of feeding experiments. Participants were given a first course of casserole and a glass of water; the same casserole mixed with the water to make a soup mixture; or the casserole alone. Results showed that those given the soup mixture took in about 100 fewer calories at lunch compared to those who ate the casserole either with or without a glass of water. This represented a 26% reduction in caloric intake following the soup compared to either casserole option.2
Dr. Rolls also measured soup’s effectiveness in sustaining satiety, finding that people who ate a low-calorie lunch including soup did not compensate by eating more at dinner. In another study, Dr. Rolls compared the effectiveness of a first course of tomato soup, melon or cheese and crackers, each consisting of 200 calories and found that at the next meal, soup eaters consumed 50-200 fewer calories.
In addition to soup as a first course or as the main meal, Dr. Rolls suggests snacking on soup instead of a higher-calorie option – especially broth-based varieties like chicken noodle, tomato and vegetarian vegetable.
Satisfy Hunger with Fewer Calories
Dr. Rolls shares her latest research on soup in her book, Volumetrics, published by HarperCollins 2000 and scheduled to be released for the first time in paperback this January. Volumetrics has been acclaimed by the Tufts University Health & Nutrition Letter, the Washington Post and USA Today. It focuses on the inclusion of low energy-dense foods like soup that are rich in water content, therefore containing fewer calories per gram. Other low energy-dense foods that Dr. Rolls recommends include fruits, vegetables, cooked grains and lean meats.
For more information on soup as part of a healthy eating strategy, including recipes and suggested menus, visit the Campbell Soup Company web site at www.campbellsoup.com.
1. Crawford D, Jeffery RW, French SA. Can anyone successfully control their weight? Findings of a three year community-based study of men and women. International Journal of Obesity. 2000; 24: 1107-1110.
2. Rolls, B.J., et al. Water incorporated into a food but not served with a food decreases energy intake in lean women. American Journal of Clinical Nutrition. 1999; 70(4): 448-55.