Previous studies have found a link between dehydration and lowered resting metabolism. Bodybuilders and other athletes often resort to using diuretics to lose excess water; however, losing too much water can easily lead to dehydration. Researchers from the University of Utah tested the effects of both over-the-counter herbal diuretic supplements and a potent pharmaceutical diuretic on resting metabolic rates.
The results showed that using herbal diuretics induced a small dehydration effect, not enough to significantly affect resting metabolism; however, the authors suggested that larger doses may be sufficient to lower resting metabolism.
The study involved 14 women, some of whom got one milligram per kilogram of bodyweight of Lasix, a potent diuretic, while others got a placebo. Those taking the diuretic clearly had lowered resting metabolic rates, which can result in decreased fat metabolism, or poorer dieting results. The lesson here is that herbal diuretics can help you lose some excess water, but drug versions are overkill that will hamper fat-loss efforts by lowering your resting metabolic rate. IM