The OPTIFAST Weight Loss Programme is based on a very low calorie diet (VLCD).
It provides roughly 800 kcal (or 3400kJ) of energy per day, for the first 8 weeks(Intensive phase).
Depending on an individual, conventional weight loss diets contain more than twice the amount of energy daily.
The Programme has shown to significantly reduce body weight by 1-2.5 kg per week.
It consists of three scientifically formulated products (shakes, bars o vegetable soups) taken daily for 8 weeks as a meal replacement, with low-carb vegetables and salad as desired.
After the initial 8-week period, a 4-week period of gradual food reintroduction follows.