Today I’ve read an article about maintaining your weight after a diet and drinking green tea. The paper’s source can be found at the bottom of this article.
Obesity sucks. It causes premature mortality and severely impacts the lives of millions of people. Surprisingly enough, we all know how to fight it: stick to a healthy diet, do exercises, sleep well, etc.
Nonetheless, fighting obesity after it occurred doesn’t seem like an easy task. If losing weight, even a modest amount, is highly beneficial, long-term maintenance of the bodyweight is difficult.
The scientific paper I’ve read today is named: “Effects of green tea on weight maintenance after body-weight loss” and precisely studies the effect of green tea consumption on people who just went out of a strict diet. The main purpose of such a study is to see if drinking tea (and absorbing its constituents) may have a positive impact on our ability to not gain the weight back.
The methodology of this scientific study is simple but very efficient: the authors gathered 120 overweight males and females between 18 and 60 years old. The BMI of the participants is comprised between 25 and 35kg/m² (which actually goes from slightly overweight to strict obese).
The subjects of this study had to go on a “very-low-energy” diet for 4 weeks which resulted in an average weight loss of 6.4kg (equivalent to 7.5% of the participant's body mass on average). From there, they had to stick up to their current weight for the next 13 weeks. During this “weight-maintenance” period, half of the people had to ingest a capsule of green tea per day, and the other half were given a placebo. After 13 weeks, the weight of each person has been evaluated again and the authors have been able to test the hypothesis that ingesting green tea had a positive effect on weight maintenance.
On average, the “green tea” group gained 18.9 grams per day against 11.6 grams per day for the placebo group which seems to indicate that ingesting green tea had a negative impact on weight maintenance. But taking into account the standard deviation of this rate of gain and the number of people in each group, the authors stated that the results were not statistically different. In other words, there was no significant difference in weight gain between the two groups.
So, does drinking green tea negatively impact weight maintenance? Well, the authors also found that within the “green tea” group, the people who were used to consume higher levels of caffeine (which is present in both coffee and green tea), seemed to have regained significantly more weight than the other people. This could indicate that drinking green tea may be effective for weight maintenance only on people who consume low amounts of caffeine a day.
In conclusion, after a weight loss, green tea doesn’t improve your chances of maintaining your weight.
Source: Kovacs, Eva MR, Manuela PGM Lejeune, Ilse Nijs, and Margriet S. Westerterp-Plantenga. “Effects of green tea on weight maintenance after body-weight loss.” British Journal of Nutrition 91, no. 3 (2004): 431–437.