Tea is one of the most common drinks around the world. Both decaffeinated and caffeine-free teas are reasonable hydration sources, which quench your thirst and can make you feel fuller if you are dieting to lose weight. If you have been diagnosed with tachycardia, or an irregular heart rhythm, be aware that even decaffeinated tea may have just enough caffeine in it to trigger an episode, according to Women's Care of Alaska. Always consult your doctor before making any significant changes to your dietary habits.
According to the USDA Nutrient database, decaffeinated tea contains almost zero calories or fat, when taken without creamer or sweetener. If you are controlling your calorie intake with a goal of weight loss or weight maintenance, drinking decaffeinated tea will not contribute any significant calories to your diet. There are almost no nutrients whatsoever in decaffeinated tea, other than trace amounts of carbohydrate and minerals found in tap water.
Caffeine is present naturally in tea, coffee and chocolate products. According to the July 2005 issue of "Obesity Research," the caffeine in regular tea may have a small beneficial effect on weight-loss efforts. There is a difference between decaffeinated tea and caffeine-free tea. Herbal teas, such as peppermint, lemon or chamomile, are naturally free of caffeine. However, black or green decaffeinated tea still contains some caffeine. Regular black tea typically contains between 14 and 61 milligrams of caffeine in an 6 to 8-ounce serving. The same amount of decaffeinated black tea contains between less than 12 milligrams of caffeine, according to the October 2008 issue of the "Journal of Analytical Toxicology."
Tea contains organic compounds known as flavonoids. An article published in the May 2000 issue of the "International Journal of Food Sciences and Nutrition" indicates that the flavonoids in tea -- caffeinated or decaffeinated -- have antioxidant properties. Antioxidants are believed to reduce your risk of cardiovascular disease and to protect against certain types of cancer. Adding milk or cream to black or green teas generally reduces their antioxidant properties.
If you are highly sensitive to caffeine, even the small amount of caffeine present in decaffeinated tea may cause problems. Caffeine sensitivity may occur in isolation, or as a facet of neurological disorders or heart problems. Because decaffeinated tea contains very little caffeine, it is a good choice for drinking in the afternoon and evening, as it should not disrupt your sleep the way that caffeinated teas might. Excessive consumption of dark teas may lead to your teeth becoming stained -- brushing your teeth after drinking tea can reduce this risk.