All green and black tea is brewed from the leaves of one bush, the camellia sinensis.
While black tea leaves are fermented, green tea is steamed and dried right after
picking.This gives it a different composition, including a whole lot more catechin
polyphenols, chemicals that act both as an antioxidant and as a metabolism booster.
Green tea has about 27 percent catechins, while black tea has just 4 percent. (Sorry,
Grandma, but herbal teas like chamomile don't have any). When Swiss researchers
gave volunteers a green-tea extract with every meal, the subjects displayed a 4
percent increase in energy expenditure over the next 24 hours.
A boost the scientists attributed to the combination of catechins and caffeine.
A 4 percent increase doesn't sound like much, but it could make a significant difference
to someone who is training seriously and eating right. Look at it this way: If you're
taking in 2,200 calories a day and neither gaining nor losing weight, that extra
4 percent will translate into 88 burned calories. If you make no other dietary or
lifestyle change, you'll still lose almost nine pounds during the next year. Apart
from the calorie savings, tea appears to give an extra boost by encouraging your
body to burn fat rather than carbohydrates.
