Testosterone and estrogen are not the only hormones implicated in weight gain. Low levels of DHEA (dehydroepiandrosterone), a steroid hormone, have also been linked to increased weight gain. Virtually everyone over age 35 experiences a significant reduction in DHEA. Studies suggest that supplementing with DHEA produces beneficial body composition changes (Villareal et al 2000; Villareal et al 2004).

For example, a 6-month trial in aging men and women with low DHEA levels demonstrated that 50 mg of DHEA per day reversed age-related changes in fat mass (Villareal et al 2000).

Another study showed that DHEA decreased abdominal obesity and improved insulin action. This randomized, double-blind, placebo-controlled trial evaluated 50 mg of DHEA per day for 6 months in 56 individuals with age-related decline in DHEA levels.The study showed that DHEA was associated with significant decreases in visceral and subcutaneous fat and improved insulin sensitivity (Villareal et al 2004).

Note: In woman DHEA can convert to testosterone, which is acceptable as long as testosterone is kept within proper range.

7-keto DHEA
A metabolite of DHEA called 7-keto DHEA has also attracted considerable attention for its value as a fat-loss supplement. Like DHEA, 7-keto DHEA levels dramatically decline with age (Marenich 1979).

In animal studies, 7-keto DHEA boosted fat-burning enzymes (Bobyleva et al 1993; Bobyleva et al 1997). Studies using 7-keto DHEA supplements produced encouraging results. For example, researchers assessed the effects of taking 100 mg of 7-keto DHEA or placebo twice daily for 60 days. Compared with placebo, the 7-keto group lost more body weight (6.3 lb vs. 2.1 lb). This study also found that supplementing with 7-keto DHEA was associated with a significantly greater percentage of body fat loss compared with the placebo group (Kalman et al 2000).

Because of the fat burning, or thermogenic effects of 7-keto DHEA, simultaneous supplementation with antioxidants is recommended to help guard against excessive free radical production. Animal studies have shown that 7-keto DHEA is not converted into testosterone or estradiol (Lardy et al 1995). Unlike caffeine or ephedra, 7-keto DHEA does not have a noradrenaline-induced central nervous system stimulating effect, nor does 7-keto increase heart rate or blood pressure.