The Special K diet is a 14-day program that involves replacing two meals a day with a bowl of Special K cereal and low-fat milk. You can also snack on whole fruits, vegetables, and portion-controlled Special K bars or shakes a couple of times a day. The third meal of the day can be a regular, balanced meal.

This diet plan, sometimes called the “Special K Challenge,” was created by the Kellogg Company. The diet claims to help you lose up to six pounds, or drop a pants size, in just two weeks.

The specifics of the diet are no longer available on the Kellogg website — nor are they currently promoted by the company. Details are still available online through various sources, though.

While there is some evidence that this diet may help you lose weight quickly, there are several factors to keep in mind if you decide to try it.

Read on to learn more about the benefits and risks of this diet

There are no foods that are off limits on the Special K diet. The bulk of what you eat involves Special K cereal, Special K bars, and Special K shakes. Beyond that, try to prioritize the following foods:

  • fresh fruits
  • fresh vegetables
  • low-fat dairy products
  • lean protein
  • whole grains
  • water and other sugar-free beverages

With the Special K diet, a typical daily meal plan might look something like this:

Breakfast 1 cup of Special K cereal with half cup skim milk
SnackA piece of fruit
Lunch1 cup of Special K cereal with half cup skim milk
Snack A Special K bar or shake
DinnerEat a regular meal, but keep an eye on your portion sizes

There are no specific meal or snack timing guidelines. If you wanted to, you could have your “dinner” meal at lunchtime or even in the morning. You can also switch your snacks around however you’d like. The main goal is to replace two meals each day with cereal and milk.

As with any diet, there are pros and cons. One of the biggest pros is that the diet is easy to follow and doesn’t require much planning. On the flip side, you may get tired of eating cereal, and you may get hungry, too.


  • Special K cereal is readily available at most grocery stores.
  • No special cooking or preparation is needed. Just pour and eat.
  • You are encouraged to eat breakfast and not skip meals.
  • The diet is suitable for vegetarians.
  • If you stick to the plan, you will likely see results, at least in the short-term.
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  • Special K may be too low in calories to keep you feeling full for long.
  • The diet doesn’t provide guidelines for what you should eat for dinner, so you may end up eating foods that are too high in calories.
  • Exercise is not part of the program.
  • Weight loss may only be temporary, possibly leading to yo-yo dieting.
  • You have to buy Special K cereal and other branded products.
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A healthy diet is one that includes whole foods in the right portion sizes and from many food groups. In addition, it should be complemented by an exercise component. The Special K diet is lacking in some of these areas.

Also, by taking in a lot fewer calories, this diet may affect your energy levels and mood. You may feel tired and irritable as well.

Nutritional value of Special K Original Cereal

Since the diet was first introduced, many other Special K brands have been added beyond the Original cereal. It’s a good idea to read the nutrition labels of the different Special K cereals. Compare the nutrients in the different options and try to stay away from any that have a lot of added sugars.

A cup of Special K Original Cereal with a half cup of nonfat milk provides the following:

200 calories402 milligrams of potassium
0.7 grams of fat34 grams of carbohydrates
322 milligrams of sodium14 grams of protein

Special K Original cereal is fortified with vitamins:

  • A
  • B-6
  • B-12
  • C
  • E
  • folic acid
  • niacin
  • riboflavin
  • thiamin
  • iron selenium
  • zinc

It does not contain saturated fat and, because it’s processed, doesn’t contain much fiber.

One study funded by Kellogg’s Co. Ltd showed that participants on the Special K diet lost between 0 and 13 pounds at the end of two weeks. Some people in the study lost up to 10 percent of their body fat, and the average weight loss was around 3.5 pounds.

The people in this study cut their daily calorie consumption by an average of 673 calories while on the diet. Their fat intake was also cut by 50 percent.

A review of studies echoed these results. Participants lost an average of 3.5 pounds, and an inch off their waistlines.

These studies both focused on short-term weight loss. They didn’t look at whether the participants were able to maintain their weight loss after two weeks.

So, the short answer is yes, the Special K diet may lead to weight loss. What’s less clear from the research is whether you can keep the weight off once you go back to eating three regular meals a day.

If you have a health condition or if you’re unsure if this diet is right for you, be sure to talk with your doctor before starting it. It’s also generally a good idea to ask your doctor before you make any changes to your diet, even if it’s only for a short period of time.

If you are a healthy adult and you don’t have any health issues, this diet may help you shed a few pounds fairly quickly. It may also be a good way to help you establish healthy eating habits, like not skipping breakfast or other meals during the day.

Additionally, it may help motivate you to follow a longer-term weight loss program.

If you are looking for a diet that you can stick with long-term, the Special K diet is not the best option due to its restrictive meals and low calorie intake.

For longer-lasting weight loss, experts recommend incorporating both diet and exercise into your weight loss plan. Instead of dropping weight quickly, a more realistic goal is to aim for weight loss of one to two pounds a week.

The National Weight Control Registry has a database of some 4,800 people who have successfully maintained their weight loss. Their secret to keeping the weight off long-term included:

  • eating breakfast
  • exercising every day
  • following a balanced diet

Beyond food, try to shoot for 150 minutes of moderate to vigorous exercise each week to maintain your weight. This is about 30 minutes each day, five days a week. If you want to lose weight, current guidelines recommend that you exercise up to 60 minutes a day.

Before you stock your pantry with cereal, evaluate your weight loss goals. If you’re looking to drop a few pounds fast, the Special K diet may help you achieve quick results. But, it’s not the best option if you’re looking for a diet to follow for longer than two weeks.

By jump-starting your weight loss, the Special K diet can motivate you to keep shedding pounds. However, the safest way to keep weight off and to continue trimming your waistline is to follow a balanced eating plan that you can stick to, and to include exercise in your weight loss program.