A lot of people post about fat burners on this forum so I thought I would make a post about scientific studies behind the effectiveness of fat burners.
OTC FAT BURNERS
The only OTC fat burner that has been scientifically studied is the EC stack and a lot of people are unclear on the effectiveness of the EC stack.
Before I go into the studies of EC's effectiveness I would like to say that EC is the most effective OTC fat burner. This may be debated but even if I am wrong in this respect, no OTC fat burner could possibly claim to be twice as effective as EC and as these studies show even twice the effectiveness of EC is substantially less than most people expect from a fat burner.
EC'S EFFECTIVENESS FOR WEIGHT LOSS
Ephedrine and Caffeine administered at 25/200 mgs respectively at a max dosage of 75/600 has been attributed to 35 pounds or 16 Kg of weight loss in obese individuals on a medically supervised diet over 24 weeks compared to 22 pounds or 10 Kg of weight loss for individuals on a placebo over 24 weeks. The net weight loss associated with EC is 0.5 pounds or 0.245 Kg a week.
APPETITE SUPPRESSION AND THERMOGENESIS
So it's clear that EC works. But why does it work? Is it due to thermogenesis or appetite suppression? Studies have shown that fat loss associated with EC is 75% due to appetite suppression and 25% due to thermogenesis. This is a significant finding because many fat burners have no appetite supression properties and appetite suppression accounts for the majority of weight loss.
THERMOGENIC CALORIC EXPENDITURE
How significant is the thermogenic effect of EC then? This is greatly over estimated by many. Astrup et al. (1986) conducted a metabolic study of 5 healthy subjects to gauge the calorie expenditure associated with EC at normal dosage. Their findings were EC is associated with 184 calories in a 24 hour period or a 10% increase in basal metabolic rate. To put this into perspective 15 minutes of cardio on a treadmill at 14 kmh accounts for 250 calories and 2 slices of buttered bread accounts for 201 calories. You need a net calorie deficit of 3500 calories to lose 1 pound or 7700 to lose 1 Kg.
These figures are all the findings of peer reviewed studies on weight loss. While it's clear fat burners such as EC work, they are of especially limited effectiveness unless a person's diet is adequate to suit their goals and administering a thermogenic to compensate for a cheat meal is clearly inadequate unless 2 slices of buttered bread is your idea of a cheat!