The effect of peanut and grain bar preloads on postmeal satiety, glycemia, and weight loss in healthy individuals: an acute and a chronic randomized intervention trial

Abstract

BackgroundPeanut consumption favorably influences satiety. This study examined the acute effect of peanut versus grain bar preloads on postmeal satiety and glycemia in healthy adults and the long-term effect of these meal preloads on body mass in healthy overweight adults.MethodsIn the acute crossover trial (n = 15; 28.4 ± 2.9 y; 23.1 ± 0.9 kg/m2), the preload (isoenergetic peanut or grain bar with water, or water alone) was followed after 60 min with ingestion of a standardized glycemic test meal. Satiety and blood glucose were assessed immediately prior to the preload and to the test meal, and for two hours postmeal at 30-min intervals. In the parallel-arm, randomized trial (n = 44; 40.5 ± 1.6 y, 31.8 ± 0.9 kg/m2), the peanut or grain bar preload was consumed one hour prior to the evening meal for eight weeks. Body mass was measured at 2-week intervals, and secondary endpoints included blood hemoglobin A1c and energy intake as assessed by 3-d diet records collected at pre-trial and trial weeks 1 and 8.ResultsSatiety was elevated in the postprandial period following grain bar ingestion in comparison to peanut or water ingestion (p = 0.001, repeated-measures ANOVA). Blood glucose was elevated one hour after ingestion of the grain bar as compared to the peanut or water treatments; yet, total glycemia did not vary between treatments in the two hour postprandial period. In the 8-week trial, body mass was reduced for the grain bar versus peanut groups after eight weeks (−1.3 ± 0.4 kg versus −0.2 ± 0.3 kg, p = 0.033, analysis of covariance). Energy intake was reduced by 458 kcal/d in the first week of the trial for the grain bar group as compared to the peanut group (p = 0.118). Hemoglobin A1c changed significantly between groups during the trial (−0.25 ± 0.07% and −0.18 ± 0.12% for the grain bar and peanut groups respectively, p = 0.001).ConclusionsCompared to an isoenergetic peanut preload, consumption of a grain bar preload one hour prior to a standardized meal significantly raised postmeal satiety. Moreover, consumption of the grain bar prior to the evening meal was associated with significant weight loss over time suggesting that glycemic carbohydrate ingestion prior to meals may be a weight management strategy.

Regular intake of high-oleic peanuts improves fat oxidation and body composition in overweight/obese men pursuing a energy-restricted diet

“…The first is that peanuts hold high satiety value since they are a rich source of fiber and protein (1,20,21). In this trial, there were no significant differences in appetitive ratings between groups.…”

“…In this trial, there were no significant differences in appetitive ratings between groups. A recent study reported that conventional peanut consumption lead to greater satiety compared to control treatment after 1 h of its intake (21). Given the groups consuming peanuts ingested less energy, this suggests the inclusion of peanuts in the diet did enhance satiety.…”

“…Thus, the groups consuming peanuts lost more weight relative to the level of their energy restriction. Indeed, by reducing 550 kcal day 21 . An expected weight loss of 2.0 kg in 4 weeks, which was close to the 2.2 kg found after intervention.…”

“…Individuals with acute diseases and/or eating disorders or any chronic disease other than obesity, were not included. Other exclusion criteria were the use of medications (e.g., b-blockers or diuretics, antibiotics, anti-inflammatory agents) that might affect study outcomes over the 3 months prior to study initiation and high alcohol intake (>168 g week 21 ). The study was approved by the Ethical Committee on Human Research of the Federal University of Viçosa (number: 185/2011).…”

“…Each participant's daily energy requirement was calculated, then 250 kcal day 21 were subtracted for the dietary prescription. All experimental diets provided 15% of energy from protein, 30% from fat, and 55% from carbohydrate.…”