Eating a low-calorie soup before a meal can help reduce the amount of food and calories we eat at the meal, a Penn State University study shows. In the study, when participants ate a first course of soup before a lunch entrée, they reduced their total calorie intake at that meal by 20 percent, compared to when they did not eat soup. “This study expands on previous studies about consuming lower-calorie soup as a way to reduce food intake,” said co-author Dr. Barbara Rolls, who holds the Guthrie Chair of Nutrition at Penn State. “Earlier work suggest that chunky soup may be the most filling type of soup, so the purpose of this study was to determine whether different forms of soup might have different effects on food intake.”

The study tested whether the form of soup and the blending of its ingredients also affected food intake and satiety. All of the soups tested were made from identical ingredients: chicken broth, broccoli, potato, cauliflower, carrots, and butter. However, the methods used to blend the ingredients varied, so that the form of the soup changed. Soups tested included separate broth and vegetables, chunky vegetable soup, chunky-puréed vegetable soup, and puréed vegetable soup.

Although researchers thought that increasing the thickness or the amount of chewing required might have made certain forms of soup more filling, a low-calorie soup was filling regardless of its form.

(Source: Experimental Biology Conference in Washington D.C., May 1, 2007)