This diet can achieve short-term success. The 1st 2 meals of the day have only 100-250 calories, which will help you lose weight. All the products from Special K are low in calories and fat. This is a meal replacement diet, and it takes any guesswork out of planning meals. It is easy to follow and provides freedom for your 3rd meal of the day. Studies that have been funded by Kellogg have shown that this type of meal, where low-calorie cereal meals are used, will cause weight loss. The average calories per day for the study subjects were 1,590, and they also reduced their fat by ½ on the diet.