This oft-asked question, “can tea help me lose weight?” seems simple enough, but as with all questions of weight loss the answer isn’t so simple.
In fact, looking at the research studies on tea and weight loss or post-weight-loss maintenance a number of confounding variables arise. We will consider a few of the studies in a moment.
First, what is clear is that tea can support dieting and weight loss efforts. Because it is a flavorful, enjoyable 0 calorie beverage, it is a wise choice for anyone seeking to lose weight. In fact, just switching out 1 soda per day for tea could result in as much as 15 pounds of weight loss in a year. But that is not the only way tea consumption supports weight loss efforts–read the others here.
In looking at the studies on tea consumption and weight loss, I’ve limited my review to only ones involving humans (as in vivo and animal studies do not reflect the complexities of weight loss in real life).
Recently a study on green tea and exercise garnered significant media attention. Researchers found that consuming green tea enhanced belly fat loss in conjunction with exercise in overweight and obese individuals. While there are potentially some conflicts of interest or confounding variables, the conclusion remains, if you’re willing to exercise, green tea may improve your weight loss numbers.
Another study published in the Journal of Nutrition looked at oolong tea’s effect on metabolic rate and fat oxidation in men and found that caffeine was a bigger determinant of metabolic rate than oolong catechins alone, but that oolong catechins may in fact affect fat breakdown and utilization. What this means is that if you are drinking oolong tea for weight loss, for best results, make sure it’s not decaffeinated.
Japanese researchers looked at the effect of pu-erh tea extract on overweight Japanese men. At the end of the study, the men who had consumed pu-erh tea had less belly fat and a lower body mass than the control group. This research is definitely promising for anyone who enjoys pu-erh tea (or Belight) and is trying to lose weight.
While individual studies can give us small insights, a meta study (comprehensive review of the existing studies) provides a much broader picture of what does or doesn’t work. One such meta-study evaluated the effects of green tea on weight loss and found mixed results. In their overview, the authors warned that caffeine intake prior to starting a green tea for weight loss program may limit the effectiveness of the green tea, suggesting that caffeine is the bigger driver in raising energy expenditure. Second, the authors noted that studies on Asians showed greater results than those performed on Caucasians, indicating that tea catechins may interact differently depending on ethnicity. Another issue, I believe, worth noting is the gender difference, as many of the more successful studies have used male subjects.
Ultimately, this meta study warned us about relying too heavily on green tea for weight loss, particularly if you’re already consuming caffeine, or are not an Asian male. Another important consideration is the fact that nearly all of the successful outcomes for weight loss involved a low-calorie diet. Therefore, drinking tea, while making no other changes to diet or exercise may not result in weight loss. One final note of caution from the studies is that with any weight loss attempt, compliance is a big issue. A low calorie diet, or exercise, plus daily consumption of tea may prove challenging to stick with long term.
Though many studies have shown a positive correlation between tea consumption and weight loss, when considering caveats, confounding variables, and compliance issues, the results aren’t as clear.
Nonetheless, drinking tea certainly can’t hurt, and may even enhance your weight loss efforts.