| This thesis is an investigation into the safety and efficacy of an herbal supplement containing ephedra alkaloids (20 mg/dose) and guarana (caffeine) (200 mg/dose). Half the participants received the supplement (S) 3 times daily for 12 weeks vs a placebo. After medical screening, 20 obese men, (BMI ≥ 30 kg/m2, 19–34 yr old) underwent a 12-week, caffeine-free, placebo-controlled (P = 10, S = 10), double blind, diet-exercise weight loss program. To ensure the target energy deficit of 3500 kcal/wk, daily diet records were analyzed and exercise sessions were supervised. Resting HR and BP were measured on approximately 42 of the 84 d intervention and subjective side effects were noted daily. During the 12 weeks, resting HR was moderately elevated within the S group (p < 0.05), while resting BP was not affected, other reported side effects were moderate. No significant differences were seen in body composition, serum lipid profiles or resting metabolic rates between groups. Body mass, fat mass, % body fat, fat-free mass in both groups decreased significantly over time (p < 0.001). Resting metabolic rates (RMR) expressed per kg fat-free mass did not change in either group after weight loss. These results show that the caffeine/ephedra supplement is safe when taken in a controlled manner. However, there was no impact on amount of adipose mass lost when diet and exercise are controlled, suggesting that any benefits of such ephedra and caffeine supplements are likely due to anorectic effects. |
