THE EFFECT OF THERMOGENIC WEIGHT LOSS SUPPLEMENT ON ENERGY INTAKE AND BLOOD CHEMISTRIES IN OBESE ADULTS

Abstract

The purpose of the study was to determine whether an herbal preparation containing several potential thermogenic botanicals, including: ma huang (ephedrine), bitter orange (synephrine) and guarana extract (caffeine), had any effect on blood chemistries and self-reported food intake in obese adults. Five males and 15 females (age = 31.0 ± 6.6 yr, height = 168.1 ± 8.4 cm, weight = 93.4 ± 17.1 kg, %fat = 43.8 ± 6.5%) gave informed consent, were matched according to age, gender, height, weight, and body fat, and randomly assigned to receive 2 capsules of either supplement (XEN, N = 12) or placebo (PL, N = 8) twice a day for six weeks. Subjects also participated in a 44 d walking/jogging program (1.5–2.0 mi, 3 d/wk). Following a 12-h fast, pre- and post-treatment serum samples were collected and analyzed for glucose, cholesterol, triglycerides, and high-density lipoprotein cholesterol (HDL). Low-density lipoprotein cholesterol (LDL) was calculated mathematically. Due to limited compliance, pre- and post-treatment diet recalls were analyzed for only 14 subjects (XEN = 9, PL = 5). Three-day diet recalls and blood chemistries were analyzed using doubly MANOVA repeated measures (α ≤ 0.05). There were no significant changes in the subjects' diets (P = 0.129, eta2 = 0.514, β-1 = 0.46) and between the groups over time (P = 0.822, eta2 = 0.142, β-1 = 0.10). Doubly MANOVA revealed no significant difference in the blood chemistries over time (P = 0.094, eta2 = 0.327, β-1 = 0.34). Because power was low, a more liberal significance level (α 0.10) was considered. In this case, a significant change in blood chemistries was indicated (β-1 = 0.57), however, the group differences were not significant (P = 0.822, eta2 = 0.142, 0.10 ≤ β-1 ≤ 0.18). Likewise, post hoc ANOVA revealed that the groups differed significantly (P = 0.089) only in HDL which decreased 0.93% and 11.21% for XEN and PL, respectively. These data suggest that daily supplementation with XEN does not lead to deleterious changes in diet or blood chemistries during a six week period of supplementation and training. Supported by a grant from Phoenix Laboratories