One thing you quickly figure out in your weight loss journey is that you need all the help you can get. Exercise is critical but so is what goes into your mouth. That means your meals as well as health supplements. Green tea is considered a superfood and, over the last decade or so, has been associated with dozens of health benefits. Among these is weight loss. Let’s see what science says.
What is Green Tea
Green tea is made from the same plant as black tea – camellia sinensis. The difference is in the degree of oxidation. Black tea is made from darkened tea leaves, has a stronger flavor and is fully oxidized. Green tea is made from freshly-picked steamed leaves that are green in color and have had little to no oxidation.
Green tea has a medicinal history going back thousands of years. In Chinese medicine, green tea was used to treat numerous illnesses including arthritis, headaches and depression.
On the other hand, it was viewed as highly toxic by many in the West. Modern science has confirmed some of the benefits espoused in traditional Chinese medicine and unearthed many more. Our focus here is on weight loss so I’ll take a look at studies that are most pertinent to that.
Weight Loss-Related Studies
Let me state at the outset that science does make a compelling case for green tea’s weight loss efficacy. And it appears to aid weight loss in multiple ways.
The Caffeine Question
Green tea contains caffeine though the amount is just a third of what you would find in coffee. As this article is focused on green tea, I will not go into the details of caffeine’s impact on weight loss here. I’ll only mention in passing (and link to the relevant studies) the well-documented benefits such as body fat reduction, weight loss maintenance, increased BMR, appetite suppression and endurance.
Basal Metabolic Ratehere
In a 1999 study, 10 men were randomly placed on a green tea extract (90 mg EGCG and 50 mg caffeine), 50 mg caffeine (which is the same amount found in green tea) or a placebo. The goal was to check the effect of green tea on BMR and whether this was solely due to its caffeine component. Researchers found participants who took the green tea extract exhibited increased BMR while those on caffeine saw no change.
What does this mean? Green tea’s thermogenic capabilities are not solely due to caffeine but likely its combined effect with other bioactive compounds present in green tea especially catechins like EGCG.
Body Weight, Abdominal Fat and BMI
A 2017 review looked at 15 studies that covered green tea consumption and its effects on body weight and fat. It established that taking green tea daily containing 100 to 460 mg of EGCG, reduced body weight and body fat. These findings were consistent with a 2013 clinical trial and 2009 study that in addition reported reduction in abdominal fat (thus waist circumference) and body mass index (BMI).
Blood Sugar Regulation
Green tea may boost insulin sensitivity. In 2013, researchers examined 17 trials involving 1,133 participants. The meta-analysis found that green tea consumption reduced fasting glucose and fasting insulin concentration by significant margins. This would have a beneficial impact on blood sugar regulation which can only be a positive for weight loss.
LDL cholesterol is also called bad cholesterol. Oxidized LDL builds up on arterial walls and can cause cardiovascular disease. Excess weight is linked to high levels of LDL which increases your risk of LDL oxidation. Antioxidants, compounds that green tea is rich in, are known to prevent oxidation including that of LDL. A 2000 study of green tea consumption found it significantly prevents LDL oxidation.
The studies I looked at found green tea to be most effective in weight loss when it delivered 100-460 mg EGCG daily. Broader analysis established food supplements containing green tea extract provide a daily dose of 5-1000 mg EGCG. This is consistent with weight loss supplements I have reviewed where green tea extract is usually 100-500 mg per daily serving but standardized to 23-45 percent EGCG. This translates to 23-225 mg EGCG per day.
In its beverage form, the weight loss efficacy of green tea depends on multiple factors including its temperature and steeping time. Ambient and warm temperatures are most ideal for the retention of its bioactive antioxidant compounds. If striking the right balance feels too tedious, you may be better off going for a weight loss supplement that contains green tea extract. You are more likely to get the green tea extract in the right amounts.