The green tea diet typically consists of consuming the beverage in either drink and capsule form. Legend has it that it was first consumed in 2737 B.C. when the emperor of China boiled water for drinking and green tea leaves fell into the pot. The resulting tea smelled and tasted refreshing. Buddhist monks are also part of green tea history because it is said they brought leaves to Japan from China in 800 A.D.
Green tea is one of three types of leaves from the Camellia sinensis family. The other two kinds are oolong and black. Black tea is oxidized and dried, while oolong leaves are only partially oxidized before drying.
Green tea leaves are typically steamed and then dried. All forms of Camellia sinensis contain caffeine, which may be the reason the green tea diet is effective for weight loss. Decaffeinated tea leaves tend to have less of this effect than caffeinated ones.
Caffeine increases heart rate. The green tea diet commonly consists of consuming the tea on a daily basis and, thus, consuming caffeine. When heart rate is increased, additional energy is needed to maintain basic body functions. If dieting restricts carbohydrates for quick energy production, cells may then convert fat to energy, and increase weight loss in the process.
Weight loss is a common use for a green tea diet. Unlike many other herbal weight reduction remedies, green tea has been clinically tested and proven to increase such loss. One study performed in Scotland asked participants to consume 600 to 800 mg of catechins via a green tea diet, daily for 14 days. Results showed a mean body weight reduction of 2.11 pounds (0.96 kg).
The same study showed other potential health benefits of a green tea diet. These included reduction in total cholesterol, systolic blood pressure, and diastolic blood pressure. According to a study published by the Journal of the American College of Nutrition, green tea may also reduce the risks of cardiovascular disease and cancer. Future studies are required to assess potential benefits of a green tea diet in accordance with lifestyle and environmental factors.
This diet may be effective for more than just weight loss in other ways as well. Studies have shown green tea is an effective antibacterial, immune booster, and antiviral. One British study showed a green tea diet inhibited acetylcholinesterase, butyrylcholinesterase, and beta-secretase. These chemicals are responsible for discouraging brain messengers and depositing the protein and plaque deposits associated with Alzheimer’s disease symptoms.