German researchers have shown that drinking about 2 cups of cold water can temporarily boost metabolic rate by roughly 30%. The effect appears to be mainly due to an increase in norepinephrine.
Certain energy drinks have been shown to boost fat loss. University of Oklahoma (Norman) researchers reported in a 2008 study that when 60 male and female subjects consumed a diet energy drink containing 200 mg of caffeine and 250 mg of EGCG from green tea extract for 28 days, they lost more than 1 pound of bodyfat without changing their diets or exercise habits.
Drinking whey protein as a between-meals snack is a smart way to enhance not only muscle growth but also fat loss. UK researchers found that when subjects consumed a whey protein shake 90 minutes before eating a buffet-style meal, they ate significantly less food than when they consumed a casein shake beforehand. The scientists reported that this was due to whey’s ability to boost levels of the hunger-blunting hormones cholecystokinin and glucagonlike peptide-1.