Predigested liquid protein diets became the rage in 1976, when Robert Linn, an osteopath, wrote the national best seller The Last Chance Diet. Predigested liquid protein is still used for weight loss under medical supervision. The most common forms are individual liquid packets that are added to a bottle of water, and ready to eat Jello. Both forms contain 15 grams of protein per serving and 60 calories. Most patients have 2 – 15 gram portions – 2, 3 or 4 times a day – for a total of 60, 90 or 120 grams of protein a day. The diet can be safe and effective for very rapid weight loss, under medical supervision.