What it is: tapeworms will reduce calories. The idea is to ingest the worm so all the food is split between the worm and your own body. This means you can eat more calories and still lose weight 2x as fast if you was just exercising and eating healthy.
Where to buy them: Since they're illiegal here in America if you wanted one you would have to travel to Mexico. There you pay a "clinic" $2,000 to ingest beef tapeworm cysts. The cyst allows the tapeworm to grow inside your intestines.
What it does to your body: Ingesting tapeworms can cause cysts to form in eyes, brain, spinal cord, and the liver. It causes intestinal blockage and malnutrition. It interferes with your digestion and absorption of nutrients.
Afterwords: when the weight los goal is completed, you would then go see a real doctor in your country and they would prescribe a dose of antibiotics to kill the worm.
Pros: Guaranteed weight loss
Cons: not available in most countries, may cause death.
Poster of Tapeworm Dieting from the old days.
sources: diet-blog.com, faddiet.com