The diet: High fat, high protein, and very low carbs. When you consume few carbohydrates, your body enters a state called ketosis, and it supposedly starts burning its own fat for fuel.
Typical meal: An eight-ounce hamburger minus the bun and lettuce with full-fat salad dressing
Safe for adults? Perhaps, but with supplements. The diet lacks vitamins generally found only in produce, and experts are split over the safety of such a high-fat plan. Some maintain that any weight loss is mainly water and will come back.
Safe for kids? Absolutely not. Ketosis isn't healthy for them, and they need nutrients like vitamin C and calcium.
The diet: A plan that consists of 50 to 60 percent whole grains and 20 to 30 percent vegetables, with limited fish, fruits, nuts, and seeds. No red meat, poultry, dairy, or sugar.
Typical meal: Brown rice, baked tofu, miso soup, and herbal tea
Safe for adults? Yes, but only with supplements like calcium and B12.
Safe for kids? No. Studies show that kids on a macrobiotic diet become malnourished and have weak bones.
The diet: Unprocessed and organic plant-based foods, such as fruits, vegetables, nuts, and grains. The main requirement: Nothing is heated above 118 degrees (the temperature at which energizing enzymes break down, say raw-foods followers).
Typical meal: Raw vegetable soup, vegetable nut loaf, and coconut water
Safe for adults? Yes, with a multivitamin and fatty-acid supplements.
Safe for kids? No. Growing bodies need protein and available calcium, which may be in short supply here.