Smoothies lessen your food cravings. Packed with soy, whey or soy protein, good fats, yogurt, fresh fruits, among others, smoothies make you feel full for hours. A study conducted in New York Obesity Research Centers reveals that people who drink soy-based drinks lost three times more weight than those who consumed the same amount of calories eating regular food. In a 90-day trial, subjects who were given a certain smoothie as a meal replacement lost weight five times faster compared to those who were given the traditional low-calorie meal. In a similar study, the Journal of American Dietetic Association showed that twice as much weight is lost by those replaced a meal with smoothies than those who were given the traditional diet with the same amount of calories. This study was done in span of twelve weeks.Smoothies ar maleextra e a metabolic boosting breakfast. They set your metabolism for the day and will curb your mid-morning and afternoon appetite. The food that you will have in the morning will determine your blood sugar levels for the rest of the day. In a high carbohydrate diet, the blood sugar levels will rise rapidly but will decline to an extremely low level before 6 hours. This decline in sugar level will reduce the food-burning capacity of the body, causing fatigue and inefficiency. As the body slows down food-burning, more and more energy is converted into fat. However, in a high protein diet, the body gets a prolonged supply of glucose that makes food-burning more efficient and last longer. After consuming the high protein meal, the blood sugar level becomes faster and the blood sugar level will stay high in the entire six hours.