Black Tea to Lose Weight

Black tea contains no calories if you drink it without adding sugar, use artificial sweeteners or drink bottled diet iced tea. If you're dieting, it can boost your weight loss efforts because of two of its properties: caffeine and catechins. Caffeine is a stimulant and catechins are antioxidants. Both speed metabolism.

Caffeine in Black Tea

The caffeine content of black tea varies considerably. Generally, loose leaf black tea contains the most and bottled iced tea contains the least. Processing required to bottle diet black tea tends to reduce its caffeine content, but the quality of the tea and the length of brewing time also play roles. According to the U.S. Department of Agriculture, the caffeine in regular brewed black tea ranges from 40mg to 120mg, while the caffeine in diet bottled green tea runs between 7mg and 26 mg. By comparison, the caffeine in a cup of generically brewed coffee contains between 95mg and 200 mg of caffeine.

Catechins in Black Tea

All tea---black, oolong, green and white---comes from the same plant and all contain antioxidants called catechins, known for their weight loss properties and other health benefits. The number of catechins is reduced through oxidation. Black tea, oxidized the longest, contains the fewest catechins among the four. Processing the tea --- bottling commercial brands of diet black tea, for instance --- tends to further reduce catechin content. Brewed black tea contains about 28 mg of catechins, according to the USDA, and diet iced black tea about half as many, depending on the brand.

Black Tea is a Weak Source of Catechins

Catechins, scientific studies demonstrate, boost metabolism and burn fat. Diet black tea is among the weakest sources of catechins. Diet black tea contains less than 10 percent of the catechins contained in green tea. Brewed black tea contains twice as many catechins as bottled tea. Bottled black tea compares to red wine in catechins. Some foods, including blueberries, blackberries, black plums and dark chocolate contain more catechins than both regular brewed and bottled diet black tea. The differences may be significant if you are drinking black tea as a weight loss supplement.

Scientific Study

One study that specifically tested the effects of differing amounts of catechins in tea was conducted by Kevin Maki and other U.S. scientists in 2009 and reported in the "American Journal of Clinical Nutrition." Men in the study who reduced their food intake by 500 calories a day and consumed 22mg of catechins in black tea lost 2.9 lbs. in 12 weeks. Men who similarly changed their diets but included 600 mg of catechins from green tea lost 5.4 lbs. and substantially reduced their waist sizes. To achieve the weight loss of the green tea drinkers, you would theoretically need to drink 30 cups of brewed black tea or 55 cups of bottled diet green tea a day.

Considerations

If you are sensitive to caffeine, you could drink decaffeinated black tea. Decaffeinated products still contain some caffeine, so if you are highly sensitive, you should consult a physician before adding black tea to your diet. Pregnant women should avoid consuming more than 100mg of caffeine daily, according to the "British Medical Journal." If you want the taste of diet black tea but want to retain the catechins in brewed tea, you could make iced tea at home and add artificial sweeteners.