Beverages can be just as important as food when you're trying to lose weight. For example, trading drinks that are high in calories for those that are calorie-free, such as green tea, can help make it easier to cut your overall calories. Green tea may also have some additional benefits for weight loss, although simply adding green tea to your diet isn't likely to result in significant amounts of weight loss. It may be better to drink your green tea before meals instead of after them to get the most benefits.
Green Tea and Weight Loss
Drinking 4 cups of green tea or 4 cups of water along with green tea extract helped obese individuals lose weight in a study published in the Journal of the American College of Nutrition in 2010. The people who drank green tea lost about 5 pounds more during the course of the 8-week study than those who only drank water, and those who consumed the extract lost about 4 pounds more. This is most likely due to epigallocatechin-3-gallate, or EGCG, a beneficial substance found in green tea that's classified as a catechin.
Green Tea and Fat Loss
Consuming the catechins in green tea helped women lose body fat, including abdominal fat, in a study published in Obesity in June 2007. Another study, published in Obesity Research in 2005, found that the mix of caffeine and EGCG in green tea helped increase metabolism and fat burning, and thus weight and fat loss, compared to consuming a placebo. A review article published in The Journal of Nutritional Biochemistry in January 2011 notes that caffeine and catechins appear to work synergistically, with each increasing the potential weight-loss benefits of the other.
Timing of Green Tea
You may not want to drink green tea at the same time as you consume dairy products, as it seems that the milk proteins inhibit the beneficial effects of green tea on metabolism, according to a study published in Nutrients in 2011. Although drinking tea after meals will still provide you with the caffeine and catechins that may help with weight loss, it may be an even better idea to drink the tea before meals. Drinking something before you eat helps fill you up so you eat less at your meal. For example, a study published in Obesity in 2011 found that even drinking plain water before each meal helped increase weight loss.
Increase Effects With Exercise
Exercising is important during weight loss as it makes it more likely that you're losing mostly fat and helps limit the loss of muscle. A study published in The Journal of Nutrition in 2009 found that a combination of exercising at least 180 minutes per week and drinking green tea may help to increase abdominal fat loss over exercise alone. Abdominal fat is one of the more dangerous types of body fat, as it increases the risk for certain health conditions, such as Type 2 diabetes and heart disease.
Beneficial Dietary Changes
The effects on weight of green tea alone are very minimal. To lose a significant amount of weight, you'll need to cut calories as well. Eliminating 500 calories per day from your diet will help you lose about 1 pound per week. Focusing on eating mainly whole, relatively unprocessed foods, such as fruits, vegetables, whole grains and lean protein sources and limiting highly processed foods and those high in fat or sugar can make it easier to lose weight. Foods high in protein or fiber tend to be particularly filling.
While green tea consumption is safe for most people, some people may not want to drink the amount required for weight-loss benefits. Green tea can slightly inhibit the absorption of iron and the B vitamin folic acid, and it may interfere with numerous medications, including blood thinners and the cancer medication bortezomib. If you're taking medications, check with your doctor or pharmacist about whether green tea is safe for you.
People sensitive to caffeine may want to consume at least some of their green tea in a decaffeinated form. Potential side effects from drinking large amounts of green tea include gastrointestinal issues, such as constipation and upset stomach, as well as headache and dizziness. MedlinePlus notes that drinking more than 5 cups per day of green tea may not be safe because of its caffeine content.