Satiating properties of meat-preparations: role of protein content and energy density

To investigate the effects of three beef-based preparations (roast-beef, boiled beef, canned beef in jelly) on satiety and eating behavior.

Ten male and ten female healthy volunteers (normal weight for height) were recruited. Three different studies were conducted, all with a within-subjects design. In Study 1, the effect of the beef-preparations on the specific satiety was evaluated by ad libitum consumption. In Study 2, the effect of the beef-preparations, proposed as a first course (preload) of a complete meal, on the total energy intake was explored. Subjects were asked to eat the beef-preloads (260g for women; 400g for men) in full, and then to consume as much as they wanted of a test meal. A no-load condition (ad libitum test meal consumption without any meat-preload) was included. In Study 3, the contribution of three different amounts of canned beef, served with a fixed amount of salad, on the desire to eat and satiety sensations over time was evaluated.

In Study 1, energy, weight and protein intakes were significantly affected by the type of beef-preparation, but not by pleasantness. In fact, specific satiety was reached with comparable amount of boiled meat and roast-beef, whilst canned meat was eaten in a higher amount, despite a lower rating of pleasantness. In Study 2, total energy was independent of the type of beef-preparation and was always lower than in the no-load condition; on the contrary, weight intake was similar in all conditions. From Study 3, a significant effect of time and low-energy protein food portion/time interaction on satiety ratings was observed.

The satiating properties of the beef-preparations did not depend strictly on protein content; on the contrary, physical characteristics and, mainly, energy density seemed the most effective determinants. However, small portions of low-energy dense-protein foods seemed to be useful in modulating satiety sensations. On the whole, our results suggest that high protein intakes are not necessarily the only way to control food intake.