The effects of α-GPC supplementation on growth hormone, fat loss, and body composition in overweight adults
Creators: name: Maldonado, William G.
Publisher: name: No Publisher Supplied
Year: 2019

description: In the United States, there is an increasing prevalence of obesity that is associated with health risks, and, as such, the need for effective weight loss methods is becoming increasingly more important. In the elderly, α-GPC has been shown to significantly increase growth hormone (GH) concentrations, a major stimulator of lipolysis and protein synthesis. However, very little work has been done in younger individuals. PURPOSE: to investigate if α-GPC, an acetylcholine precursor, could confer additional GH or weight loss benefits to active, overweight individuals while exercise and nutrition are maintained. METHODS: Participants were randomly assigned to either α-GPC (n=15, Mage=25.8±9.1y, MBF%=35.48±1.75%) or placebo (n=13 Mage=24.4±10.4y, MBF%=35.65±1.98%) after health/fitness screening. Both groups were instructed to consume two capsules of their respective supplement for a total of 1200 mg/day, one dose before their workout or on non-workout days with their midday meal, and the second dose before going to sleep, for eight weeks. Assessments were performed pre- and post-supplementation and included resting blood pressure and heart rate, activity level via Framingham Physical Activity Index (F-score), body composition via air-displacement plethysmography (fat mass [FM], fat free mass [FFM[, body fat percentage [BF%], body mass [BM]), and girth measurements (waist, hips). Additionally, blood samples were obtained for analysis of growth hormone (GH). Throughout the duration of the study participants were instructed to maintain their current activity level and diet. During the weeks leading up to pre- and post-testing, daily caloric intake was reported using MyFitnesspal. RM-MANOVAs with univariate follow-ups were conducted to determine differences between groups over the course of the trial with significance set at P&lt;0.05. RESULTS: There were no significant differences between groups for any body composition, girth measurements, GH, caloric intake, or F-score from pre- to post-intervention (P&gt;0.05). There were significant main Time effects for decreases in BF%, FM, and waist measurements (P&lt;0.05) as well as trends for decreased BM (P=0.094) and increased FFM (P=0.064). No main effects were observed for any other variable (P&gt;0.05). Univariate follow-ups showed a significant Time-by-Group interaction for an increase in SBP in the α-GPC group (P&lt;0.05). A negative trend was seen for total daily caloric intake among all subjects over time (P=0.066, ES=0.136). CONCLUSIONS: Overall, supplementation with α-GPC alone under the conditions of this study did not result in additional body mass loss, alterations in body composition, or changes in GH, when compared to a placebo. This study did show that the act of tracking diet may have been sufficient to alter behavior, however more research is required. As such a future direction should investigate if tracking diet in conjunction with maintained exercise is sufficient to produce significant body composition changes.