The satiating efficiency of foods

Experiments were undertaken to test the general hypothesis that some foods are more satiating than others, to find a mechanism for their differential satiating efficiencies, and to determine whether certain soups had a high enough satiating efficiency to recommend their addition to a meal as a way of reducing total caloric intake of that meal. In the first experiment it was found that intake of a test meal was lower after a large preload of tomato soup than after a small preload in women, but not in men. However, the total energy intake (soup plus test meal) was no less with meals which included the large soup preload than it was with meals that did not include a preload. Therefore adding a normal portion of tomato soup to a meal would not reduce its total energy intake. We noted the interesting incidential finding that total energy intake (i.e., preload plus test meal) of the meals which contained the larger amount of soup was less than the total energy intake of the meals which contained a combination of crackers, jelly, and juice. In the second experiment we confirmed this finding by showing that when equal weights of tomato soup preloads and a preload of crackers, cheese, and apple juice, which contains more energy, were given, total energy intake was less in meals which included soup. Therefore, substituting tomato soup for a more calorically dense first course could reduce total energy intake of that meal. In the third experiment, the hypothesis suggested by the second was confirmed. Two soups were more satiating than crackers, cheese, and juice. When two calorie levels were used for each preload, it was shown that calorie for calorie, these soups decreased intake of the test meal more than crackers, cheese, and juice. In the fourth experiment we showed that the mechanism for this differential satiating efficiency is not readily attributable to either bulk related factors or fat content. We suggest that the differential satiating efficiencies are related to differences in nutrient dispersion, orosensory cues, or temperature. Finally, reductions in intake were accompanied by reductions in the initial rate of eating and not by increases in the rate of deceleration. This reduction was small but consistent and suggests that foods which are more satiating reduce intake by decreasing desire to eat (i.e., hunger), not by accelerating the onset of meal termination (i.e., satiety). In fact the duration of meals was unaffected by the preloads.