5. Drink Green Tea
Green tea is an especially rich source of antioxidants called catechins. It also contains caffeine. Both of these substances can increase metabolism, but when consumed together they have a synergistic effect. They help to boost levels of the hormone norepinephrine which signals fat cells to release stored fat into the bloodstream for use as energy.
In one study healthy subjects spent 24 hours in a respiratory chamber designed to measure their energy expenditure. They were given supplements containing either green tea extract, caffeine or a placebo. Those who consumed the green tea extract supplement burned significantly more calories than the control group. They also had significantly higher amounts of norepinephrine in their urine. Caffeine alone (in the same amount present in the green tea extract) did not increase fat burning.
The amount of catechins in a cup of green tea varies depending on the precise type of tea, the ratio of tea to water, and how long it is left to infuse. A large Chinese trial investigated the effects of consuming green tea with different amounts of catechins on body weight and composition. Researchers randomly assigned 182 overweight participants to four groups. Each group was given a different type of green tea ranging from a control drink with the catechins extracted to one with extra catechins added. Subjects drank 2 cups a day for 90 days.
Compared to the control group, the group drinking the extra high-catechin tea showed significant reductions in body weight, waist circumference and intra-abdominal fat. Groups drinking green tea with lower levels of catechins also lost body fat. The researchers concluded that daily consumption of 500–900 mg of green tea catechins can exert a positive effect on abdominal fat mass.
Method: An average cup of green tea contains around 180 mg of catechins, but this can vary depending on a number of factors. To boost the amount of catechins per cup, use a good brand of loose-leaf green tea. Bring the water to a rolling boil before pouring it over the leaves, then leave it to infuse for five minutes before straining.