Nutrients for a Stronger Athletic Body

Conjugated linoleic acid (CLA), an omega-6 fatty acid, is known for benefiting the immune system, but is also being used as a safe means of body fat reduction. A study from the University of Wisconsin evaluated the safety of one CLA product (as Clarinol™, from Lipid Nutrition) over a one-year period in obese humans who were generally healthy.²⁰ This was a randomized, double blind study consisting of three phases in which subjects were given 6 g/d of CLA or a placebo. Phase one was a low-calorie diet (13 kcal/kg desirable weight) for 12 weeks or until 10 to 20 percent of initial body weight was lost. In phase two, from weeks 12 to 28, subjects were re-fed a diet providing 25 to 30 kcal/kg of desirable body weight. Phase 3 was open label, with subjects from both groups taking CLA from weeks 28 to 52. Laboratory tests showed no adverse effects of CLA, and it was concluded that CLA as Clarinol is safe for use in obese humans for at least one year.

In another 12-month study in overweight adults, CLA caused reductions in body fat mass (BFM) and increases in lean body mass (LBM) by as much as 9 percent.²¹ The double blind, placebo-controlled study randomized 180 men and women, aged 18 to 65, with a body mass index (BMI) of 25 kg/m² to 30 kg/m², into three groups and administered one of the following: capsules containing 4.5 g/d of CLA-free fatty acid, 4.5 g/d of CLA-triglycerides (as Tonalin®, from Cognis Nutrition & Health), or a placebo of 4.5 g/d of olive oil. Scientists regularly assessed each subject’s body weight, BMI, body composition and blood samples. A significant decrease in BFM was observed in both groups receiving CLA compared to the placebo, and the CLA-free fatty acid group had an increase in LBM compared to the placebo. The results were not associated with changes in diet or exercise, and concluded both forms of CLA cause a significant decrease of body fat mass over a one-year period in healthy, overweight adults.

Another study on CLA and body composition investigated the effects of six months of supplementation with 7 g/d CLA (as Clarinol) in two groups of male and female resistance-trained subjects—seven beginners and seven advanced athletes.²² During the intervention period, test subjects performed a standardized training routine three times per week and were assessed for BMI, body composition and nutrient intake. In spite of a higher energy intake, a significant reduction of body fat and an increase in body cell mass was observed in both groups.