Several companies market an herbal concoction they call “dieter’s tea,” and they all have similar ingredients. Dieter’s tea ingredients supposedly suppress your appetite, speed up metabolism and increase the rate at which you burn fat. While a few of the ingredients do suppress appetite, the only way to rev up your metabolism in the end is to build muscle. Simply drinking dieter’s tea will not cause you to lose weight, and if you drink dieter’s tea, you could cause yourself problems that will interfere with your weight-loss goals.
Natural plant extracts -- like aloe, buckthorn and especially senna, used in almost all dieter’s teas -- stimulate the colon, which has a laxative effect. The theory is that if food does not stay in your body, you can’t absorb all of its calories. According to "Go Ask Alice!," Columbia University's online health-expert advice column, that's not the way it works. The calories you take in are processed in your small intestine. By the time food reaches your colon, you’ve already absorbed the calories.
Ephedra, which comes from the Chinese ma huang plant, is no longer sold in dieter’s teas in the Unites States, but other natural plant extracts like guarana have similar effects. Guarana contains twice the caffeine of coffee, according to Swarthmore College. This may increase your heart rate, but it does not actually increase the rate at which your body metabolizes food or burns fat.
The natural plant extract hoodia is commonly found in dieter's teas. According to Huntington College of Health Sciences, anecdotal evidence from the San tribe of African Bushmen showed the hunters going for days without food while chewing on the succulent hoodia. Authentic hoodia is expensive to produce and is unregulated, so dieter's teas claiming to contain hoodia may not actually contain any.
Fiber is important to a healthy diet, but you can have too much of a good thing. The bulk-producing fibers in dieter’s tea -- which can include agar, psyllium and methylcellulose -- swell as they absorb water from your system. This can make you feel full. They also work as laxatives in the mistaken belief that the less time food spends in your intestinal tract, the less you absorb of it.
Side effects of drinking dieter’s teas include nausea, vomiting, dizziness and nervousness. Using laxatives can backfire and cause a dependence on them. Drinking dieter’s teas in place of meals robs your body of nutrition and the calories needed for energy, and can cause malnutrition. It can also slow your metabolism, which will defeat your attempts to lose weight.