This diet requires that you replace some or all of your meals and snacks with a milk- or soy-based supplement that is low in calories and fat.

There are two types of liquid diets: medically supervised types like Optifast and over-the-counter types associated with plans such as Slim-Fast or other more broad-based diet plans such as Atkins. Over-the-counter plans suggest that you replace two meals and one snack with their product, then eat a healthy, balanced third meal that should be low in fat and calories. Medically supervised plans require that you use their product for your entire food intake for a specified amount of time; intake is typically less than 1000 calories per day.

• Ready-made simplicity and convenience with shakes.
  
  
• Liquid meal replacements are low fat and often fortified with most vitamins and minerals.
  
  
• Rapid initial weight loss.

• Rapid boredom with shakes.
  
  
• Old food habits are not changed when you resume eating normally .
  
  
• Weight may be regained quickly.