A growing body of research shows that Clarinol can have positive effects on the fat to muscle ratio in nonobese people in conjuction with a healthy diet and excercise program.

1. A small clinical trial of 20 non-obese people showed a 20% reduction in body fat. A subsequent larger scale trial with 80 obese people lasting 6 months demonstrated that those treated with CLA did not regain fat mass to the same extent as those not taking CLA. This suggests that CLA preferentially produces deposition of muscle mass rather than fat mass (Atkinson et al., 1999).
2. In another study 60 overweight or obese volunteers were treated with CLA for 12 weeks. In this study a dose over 3.4g of CLA per day caused a significant reduction in body fat mass (Blankson et al., 2000). Safety parameters analyzed during this study revealed no adverse effects resulting from CLA treatment (Berven et al., 2000).
3. A Medstat research study fed 1.8 grams of CLA per day for 12 weeks to 20 healthy volunteers. A significant reduction in body fat (20%) was obtained during the study for the CLA group, while no effect was seen in the group not taking CLA (Thom et al., 1997).
4. CLA supplementation had no effect on the parameters examined and no adverse effects were observed in a study examining the effect of CLA (different forms) supplementation (3g/d) for 64 days on body composition, immune parameters and related events in 17 adult healthy women. (Zambell et al. 2000, Medina et al., 2000, Kelley et al., 2000). The CLA used in this study contained several isomers of CLA, the two active isomers, c9-t11 CLA and t10-c12 CLA, were diluted to a greater extent than in the previous studies. This may account for the lack of effect in this study.
5. A trial using 24 novice body builders consuming a daily dose of 7.2g of CLA or a placebo for 6 weeks while completing body building exercises (Lowery et al., 1998) was used to investigate the effect of CLA on muscle development. An increase in skin-fold-corrected arm girth, body mass and leg press was seen in the CLA group compared with the placebo. A similar trial investigated 28 days of CLA supplementation (6g/d) in 24 experienced resistance-trained males (Ferreira et al., 1997). Analysis showed that those athletes taking CLA improved their bench press and leg press strength considerably compared with the athletes taking placebos.        

These studies clearly show the positive effects CLA has on the fat to muscle ratio and the resulting body profile improvement. A well known shortcoming of weight loss diets is the yo-yo effect where the dieters gains most if not all of the weight back in a short time after the diet stops. CLA has been observed to dampen this yo-yo effect considerably.

In a study by Belury et al. (2003), subjects with type 2 diabetes mellitus were randomized into one of two groups receiving either a supplement containing 8g/d of CLA isomers or safflower oil for 8 weeks. The CLA isomers were 76% pure with primarily the c9-t11 CLA isomer (37%) and the t10-c12 CLA isomer (39%). The authors reported that there was a stronger correlative of the t10-c12 CLA isomer with decreased leptin levels and associated decreased glucose levels than the c9-t11 CLA isomer. Insulin levels were not affected. 

Belury MA, Mahon A, Banni S (2003). The conjugated linoleic acid (CLA) Isomer, t10-c12 CLA is inversely associated with changes in body weight and serum leptin in subjects with type 2 diabetes mellitus. J. Nutr. 133:257S-260S.