HCA group experienced a fall in BMI by an average of 6.3% compared to the average of 1.7% in the placebo group. Another interesting effect of the study was that the HCA group doubled its serotonin levels compared to the placebo group. In addition, the HCA group had a 16% reduction in the amount of food consumed per meal, compared with no change in the placebo group. In 2004: Participants in a study fell above 10.5 pounds over a period of 8 weeks Like all good researchers, Dr. Preuss tried to replicate his results in a follow-up study. That follow-up study involved more people (60 people in total, double the original study) and came to similar conclusions. In this study, the HCA group lost an average of 10.5 pounds compared to the placebo group, which lost an average of 3.5 pounds. Again, in this study, the placebo group had no appetite changes, but the HCA group reported a 16% reduction in the amount of food consumed at each meal. 2005: A study shows that HCA increases serotonin,...