Nutritional Liquid Diets

Liquid diets consist of liquids only--no regular meals. While some liquid diets have nutritional value, many are devoid of the daily recommended nutrients. As a result, they should only be followed for a short time and ideally under the close supervision of a doctor.

Protein Shake Diets

Protein shakes come in powder or liquid form. While you can't live on protein shakes forever, they do provide many essential vitamins and minerals. Most are also low in sugar and calories, and have very little fat. A liquid diet consisting of strictly protein shakes, if well-planned, provides dieters with a way to lose weight quickly without feeling deprived.

Fruit and Vegetable Drinks

The best type of liquid diet is one based on fresh fruits and vegetables--something that can be accomplished with a juicing machine. Good machines cost between $60 and $300, and allow users to liquefy anything from apples and bananas to broccoli and carrots. A juicing diet provides natural sugar, and gives dieters energy and nutrients. On the negative side, people who stay on juicing diets for a long period do not receive the recommended dose of protein.

Meal-Replacement Drinks

The idea of losing weight via meal-replacement drinks was popularized in the 1980s by companies such as Slim-Fast. Like protein drinks, these meal replacements offer vitamins, and are low in fat and calories. Most meal-replacement plans consist of two or three shakes a day, along with an actual low-fat meal. However, a lot of people wishing to remain on a liquid diet will replace their lone meal with a shake.

Sports Drinks and Juices

Sports drinks, fruit juices and energy drinks are overflowing with sugar, and severely lacking in key nutrients. A diet of sports drinks or fruit juices alone is not healthy--which is why any liquid diet including these types of drinks would be best combined with healthier drinks.

Mix and Match

The latest trend in liquid dieting involves combining a variety of drinks, many from the suggested categories above, as a replacement for your meals. For instance, a dieter may have a meal-replacement drink for breakfast, a couple fruit and vegetable drinks around lunch, and a protein or meal-replacement drink for dinner and an after-dinner snack. Sometimes, people on liquid diets will even throw in a sports drink or fruit juice for dessert.