3. The HCG Diet
HCG, or†human chorionic gonadotropin, is a hormone that the body naturally produces during pregnancy. Followers of the diet stick to a 500-600 calorie/day meal plan and give themselves injections, typically in the thigh, once a day. The diet plan was popularized in the 1950s, but is currently seeing an upswing in popularity. Critics say that the huge weight loss seen in patients has more to do with the extremely restrictive diet, not with HCG’s supposed appetite-suppressing properties.