Very low calorie diets are designed to bring on a mild form of ketosis, which means your body shifts from using primarily carbohydrates to fat as an energy source. The relative safety of ketosis is a hotly debated topic.

Lipodrene is a dietary supplement developed by Hi-Tech Pharmaceuticals, marketed as a weight-loss aid. The supplement contains ephedra extract, as well as other ingredients including hoodia, green tea extract and caffeine.

The typical modern diet includes chemicals from trace pesticides, additives and preservatives. Proponents of cleansing claim that severely restricting food intake flushes the body of these dangerous toxins. A 48-hour water diet involves drinking only fluids to cleanse the body and quickly lose weight.

Regardless of whether you prefer creamy or crunchy, eating peanut butter can support your weight loss efforts. This calorically dense spread may seem like a diet buster, but it has satiating qualities that may inhibit weight gain. You can even follow a "peanut butter"

While not for everyone, a 1,300-calorie meal plan may lead to healthy weight loss over a four-week period of time. Caloric intake varies significantly depending on your individual body weight, so it would be impractical to prescribe 1,300 calories for all dieters.

Guggul is an herbal remedy made from the Commiphora mukul tree, also known as the mukul myrrh tree. The gum resin in the tree has been used for thousands of years in traditional Ayurvdic medicine in India to treat a wide variety of health problems and diseases.

In the feast or fast diet plan, you eat what you want during feast days and restrict calories during fast days. This diet actually goes by many names, including the alternate-day diet, the up-day down-day diet and the intermittent fasting diet.

Bulimia, or bulimia nervosa, is an eating disorder that involves repetitive cycles of binging and purging, emotional upheaval and obsession with weight loss.

If weight loss was as simple as adding apple cider vinegar, cayenne pepper and garlic to your diet, the United States wouldn't be facing an obesity epidemic. While there is some truth behind the weight-loss claims for these flavor-enhancers, it's never that easy.

For a variety of reasons, black tea can contribute to weight loss as long as you drink it unsweetened. Although this makes it an inexpensive and effective weight loss supplement, unsweetened black tea can be hard on the palate.

Metformin helps control blood sugar and increase your body's sensitivity to insulin. The drug is available only by prescription and sold under several different brand names, including Fortamet, Glumetza, Riomet, Glucophage and Glucophage XR.

Despite the growing obesity epidemic in the United States, Americans spend billions of dollars on dieting products each year, according to Creighton University. The lure of pills or new diets promising fast weight loss can be hard to resist -- even if they are ineffective or dangerous.