With the recent recall of Hydroxycut and the suspension of several NFL players due to their use of a weight-loss supplement, dietary aids have come under a lot of fire within the past few months. Unfortunately, most of the general public is not very educated on this subject, and media reports can be exaggerated and blown out of proportion, leading the average consumer to think that all weight-loss drugs, or all dietary supplements in general, are unsafe or ineffective. Research from the latest edition of the Journal Of Strength and Conditioning Research, however, tells a different story.
In the study, which was double-blinded and placebo-controlled to reduce the possibility of bias and maximize accuracy, participants were given a generic thermogenic supplement, containing typical ingredients found industry-wide, such as caffeine, niacin and capsicum extract. An array of measurements were taken during four phases: 30 minutes of initial rest; 50 minutes of rest after supplementation; 60 minutes of light exercise (treadmill walking); and 50 minutes of recovery after exercise.
Researchers found several significant differences between the thermogenic and placebo groups. Energy expenditure, even at rest, was higher in the thermogenic supplement, with the biggest difference around the 50-minute mark. During and after exercise, energy expenditure increased by as much as 11% when comparing the thermogenic group to the placebo group.
Another difference was found when the researchers measured oxygen consumption rate and respiratory exchange rate. With the thermogenic supplement, there were significant increases in oxygen consumption, which in past studies has been linked to an increase in lipolysis - the breaking down of fat for energy. And while blood pressure and heart rate increased slightly, the changes were not long term or harmful.
As a result, the researchers concluded that the thermogenic aid would be helpful in weight management. However, they did note that it would be most effective when combined with exercise, and that due to side effects such as anxiety, nausea, dizziness and headaches, users should avoid consuming supplements with large (400-500mg) doses of caffeine.
In addition, the researchers cited prior research to suggest which ingredients might be most effective. They noted that "caffeine, capsaicin, bioperine and niacin my increase EE [energy expenditure] and improve body composition" (1).
1. Ryan, D., et al. Acute Effects of a Thermogenic Nutritional Supplement on Energy Expenditure and Cardiovascular Function at Rest, During Low-Intensity Exercise, and Recovery from Exercise. Journal of Strength and Conditioning Research, 2009; 23(3):807-817