A Pilot Study: Soy protein may help decrease energy intake when consumed prior to meal

Protein & fiber reduce subjective appetite ratings acutely, leading to subsequent decreased energy intake in studies with large amounts of protein & fiber. The objective of this study was to measure satiety & energy intake following consumption of snack bars containing modest quantities of soy protein, SP, (20 g), & soy fiber, SF, (8 g) and in combination. In a randomized, double blind crossover design, 40 healthy subjects were assigned to 4 treatments with 4 types of snack bars: Control (C), SP, SF, & SP + SF. Appetite effects & bar palatability (Visual Analog Scale) & post‐meal ad libitum energy intake were measured. Subjects were asked to consume 1 type of bar within 15 mins at each visit (1‐week washout between visits). Overall appetite scores were not significantly different; however, SP tended to decrease post‐meal ad libitum energy intake vs C (−43 kcal). C bars took a significantly longer time to consume than SP or SF bars (10.3 min vs. 7.7 & 8.4 min, respectively). A post hoc sensory analysis of the bars, showed significantly different chewing attributes. The lower energy intake in the SP group is consistent with previous studies & may have long term benefits.