By Mayo Clinic News Network

The Special K diet is a diet plan created by Kellogg, the manufacturer of Special K cereal. Officially known as the Special K Challenge, the diet promises that you can lose nearly 5 pounds (2.3 kg) in two weeks.

The diet encourages you to replace two meals, such as breakfast and lunch, with a low-fat, low-calorie Special K product, such as Special K cereal, protein meal bar or shake. You can eat your third meal as you normally would. You may also snack on fruits and vegetables or additional Special K products.

Replacing one or two meals a day with portion-controlled products may result in eating fewer calories than you normally would. It can also take the guesswork out of what to eat, thereby making it easier to diet. And this appears to be the case with the Special K diet, at least in the short term.

On the other hand, the Special K diet may leave you feeling hungry and deprived because of the diet's limited food options. It also may be difficult to stick to the diet long enough to reach your weight-loss goal.

And once you stop the Special K diet, you may regain any weight you lost because you haven't learned how to change unhealthy behaviors that led to your weight gain to begin with, such as overeating and lack of exercise. Remember, the key to permanent weight loss is developing healthy eating and exercise habits.