Fatty Soup As Appetizer Means Eating Less For Dinner

Many people believe that ordering an appetizer can actually make you hungrier and that you tend to eat more of your entrée as a result. However, researchers from the University of Texas Medical Branch in Galveston, Texas, feel that what you order as a starter determines your overall appetite, as absorption of fat in the small intestine induces the feeling of being full and slows down gastric emptying. The aim of this study was to investigate whether a fatty soup consumed before a meal might reduce food intake in both lean and obese subjects and whether this possible inhibitory effect would be related to changes in gastric functions.

For the study, investigators recruited 12 lean and 12 obese healthy subjects and invited each group to the lab for two sessions (eating both fatty soup and protein soup with the same number of calories and volume). Each session consisted of a 30-minute baseline of soup consumption, a 20-minute post-soup period, an "all you can eat" pizza meal, and a 60-minute post-meal period. Electrogastrogram (a test recording the electrical activity of the stomach, EGG) and electrocardiogram (a similar test recording electrical activity of the heart, ECG) were recorded during each session. Food intake was assessed by the caloric count of the consumed pizza. Several symptoms, including satiety, appetite and nausea, were rated at different times of the study. In a second study, subjects were given the soup appetizer and then taken to an "all-you-can-eat" pizza buffet together in a social setting.

When compared with the protein soup, the fatty soup significantly reduced the amount of caloric intake with the following meal in both lean (962.0 vs. 1,188.5 calories) and obese (1,331.9 vs. 1,544.6 calories) subjects. A similar reduction in caloric intake was noted in lean subjects eating in the social setting (1,555 vs. 1,825 calories), except that significantly more food was consumed in social sessions compared with the lab setting.

In addition to general caloric intake, obese subjects registered a higher appetite level after the soups than the lean controls (protein: 8.75 vs. 5.92; fat: 8.08 vs. 5.17). The percentage of normal stomach electrical rhythmi was similar between the lean and obese subjects (73.9% vs. 68.9%) before fatty soup, and was reduced after the fatty soup in the lean, but not in the obese (59.7% vs. 73.9%). Also, the obese showed a higher sympathovagal balance (1.59 vs. 0.78) and sympathetic activity (0.55 vs. 0.42) compared to the lean patients, but a lower vagal (nerve in the stomach that controls the making of stomach acid) activity (0.45 vs. 0.58).

"In this study, we found that fatty soup as an appetizer reduces food intake by about 20 percent in both lean and obese subjects and may have a therapeutic potential for obesity," said Jiande Chen, Ph.D., of the University of Texas Medical Branch and senior author of the study. "Our hope is that further studies with similar outcomes may curb those myths and that people will think about what certain foods often thought to be off-limits may be able to achieve for their overall health and weight."