Health professionals recommend losing a maximum of 2 pounds of weight per week, and both too much and too little food intake can cause health problems. Losing more than 1 pound a week can pose dangers such as irregular heartbeat, electrolyte changes and loss of muscle mass. When losing weight, the goal is to lose fat and build muscle. Muscle is needed to help burn calories, and most fad diets don't involve exercises that build muscle. Weight lost on a fad diet may be muscle rather than fat, and while losing muscle means losing a few pounds, it does not benefit the individual. Muscle helps burn calories, and losing muscle mass through fad diets can make it harder for a person to keep the weight off in the future. Nutritional deficiencies will have a negative impact on an individual's body. The natural vitamins, nutrients and minerals obtained from a balanced diet are important for bodily functions. Lack of adequate supplements for the body leads to malnutrition and can manifest itself in hair loss and brittle nails. There are some bizarre and extremely dangerous diets followed decades ago that turned out to be useless, but somehow they are still followed by people to lose weight. The tapeworm diet is one of those unusual diets. This is where a tapeworm is inserted inside a person to allow maximum food consumption without gaining weight because the tapeworm will take care of the excess calories