What Is the Special K Diet?

Special K diet

Verywell / Debbie Burkhoff 

At Verywell, we believe there is no one-size-fits-all approach to a healthy lifestyle. Successful eating plans need to be individualized and take the whole person into consideration. Prior to starting a new diet plan, consult with your healthcare provider or a registered dietitian, especially if you have an underlying health condition.

What Is the Special K Diet?

The premise of the Special K diet, sometimes also called the "K Diet," is simple. The diet is essentially a two-week challenge to consume Special K cereal (or other Special K products) as a meal replacement for two out of your three main meals each day with the promise of quick weight loss.

Although it’s only followed for 14 days, eating the same foods for two meals per day every day restricts you from consuming a variety of foods and benefiting from a variety of nutrients. Additionally, the diet doesn't establish eating patterns beyond the two weeks, so most people are likely to resort to their usual eating habits once the challenge is complete.

What Experts Say

"The Special K Diet encourages replacing meals with cereals and bars to promote weight loss—up to 6 pounds in two weeks. The health community warns that this is unsustainable. Plus, most Special K products are low in satiating fat and protein, so you may feel hungry."

Chrissy Carroll, RD, MPH

The 7-Day Diet Plan

There is some flexibility in this plan, in terms of the Special K products you choose and the one daily meal you prepare. This is one example of what a week on this plan might look like.

Day 1: Special K cereal with milk; strawberries; Special K protein shake; carrot strips with baba ganoush; turkey stuffed peppers, green salad

Day 2: Special K protein bar; peach; Special K cereal with milk; cucumbers; Mexican chicken verde quinoa casserole with chips and salsa

Day 3: Easy Sunday morning baked eggs, berries; Special K snack bar; Special K cereal with milk; roasted broccoli; Special K protein shake

Day 4: Special K cereal with milk; apple; Special K protein shake; steamed green beans; chicken Caesar salad, whole-grain roll

Day 5: Special K cereal with milk; Special K snack bar; Special K protein bar; banana; herbed mushroom Bolognese with pasta and green salad

Day 6: Special K protein shake; grapefruit; Special K cereal with milk; bell pepper strips with salsa; salmon, spinach, and mushroom quiche, whole-wheat toast

Day 7: Special K cereal with milk; carrots; Special K protein bar; blueberries; ropa vieja with rice

What You Can Eat

The essence of the Special K Diet is that it’s a portion-controlled, two-week challenge that recommends substituting two meals per day with Special K cereal. In addition, the diet allows for portion-controlled snacks, vegetables, and fruits to support short-term weight loss or weight maintenance goals.   

The diet was never intended or marketed as a long-term weight loss solution, but instead, as a jumpstart option to help you meet an initial weight loss goal.

What You Cannot Eat

The Special K diet does not have specific foods that you cannot eat as long as you consume two meals of Special K products, two snacks of vegetables or fruit, and dinner, which can consist of any foods you choose.

How to Prepare the Special K Diet & Tips

The Special K diet is simpler and has fewer rules than many other weight loss programs. Originally comprised of just Special K breakfast cereal and fruit, the diet has evolved since 2003 to include branded shakes and bars. Many Special K products are made from lightly toasted rice, wheat, and barley. Followers of the diet challenge can expect to eat:

  • 1 cup of Special K cereal with 1/2 to 2/3 a cup of skim milk for breakfast and lunch. A protein meal bar or protein shake can be substituted for lunch.
  • Fruits, vegetables, and other Special K food options should be enjoyed as snacks.
  • No restrictions are placed on the third meal of the day.

There are no set times for meals or snacks.

Pros of the Special K Diet

The Special K diet is not recommended, but it may provide a few benefits.

  • Inexpensive: While many diets require specific powders, supplements, and/or expensive ingredients, Special K products are reasonably priced. An 11.2-ounce box of Special K cereal retails for less than $5.
  • Practical: The Special K diet takes the guesswork out of what to eat at meals. You simply swap out two meals per day with a portion-controlled bowl of cereal. You'll spend less time and money planning and preparing meals. Special K cereals and other products are familiar to most people and can be easily found at your local grocery store.
  • Low-risk: The Special K diet doesn’t require you to go long periods of time without eating or to eat questionable supplements or products. It’s a relatively safe diet to follow for the short-term only.
  • Low in saturated fat, cholesterol, and sodium: The restrictive nature of this eating plan is not supported by health and nutrition experts. On the plus side, however, the diet is low in saturated fat, cholesterol, and sodium.
  • Source of nutrients: Special K cereal is a good source of vitamins A and D and an excellent source of vitamin C, iron, thiamin, riboflavin, niacin, folic acid, and vitamins B12 and B6, and can be consumed as part of a healthy, well-balanced diet. Note that these nutrients are provided in the form of artificial enrichment and it may be better to obtain them through whole foods.

Due to its limited choices and because Special K products are low in fiber and protein, the Special K diet is not considered a nutritionally balanced long-term eating solution.

Cons of the Special K Diet

The Special K diet may seem like a simple way to lose weight, but the restrictive eating plan has its drawbacks.

  • May increase appetite: There is a potential for increased appetite for those following the Special K diet. In one study, two groups of participants who consumed cereal at two meals each day reported increased hunger versus the baseline groups.
  • May lead to diet boredom: Another drawback you may experience is boredom—eating the same foods over and over again each day can be mundane.
  • Short-term solution: The Special K diet is also not a long-term solution—it's marketed as a short-term solution to follow for two weeks only. It also provides limited nutrients. Eating the same foods over and over can limit the overall amount and variety of nutrients you consume.
  • Doesn't create healthy habits: By following a short-term diet or challenge with specific meal replacement products, you’re not establishing good-for-you habits or learning how to incorporate healthy, real foods into your diet for the long-term.
  • May cause nutrient and fiber deficiencies: This eating plan restricts food groups that provide important nutrients. Special K cereals are not typically made with whole grains. Therefore, they’re low in fiber (foods higher in fiber can help you feel more full after eating them). For example, 1 cup of Special K Red Berries cereal has just 2.6 grams of fiber or about 10% of the daily value. The cereal is also low in muscle-building, satiating protein, providing just 2 grams per 1-cup serving. The cereal is also low in potassium, but the diet recommends eating fruits and vegetables, which are high in potassium, with meals and as snacks,

Is the Special K Diet a Healthy Choice for You?

The United States Department of Agriculture (USDA) shares guidance for improving and maintaining overall health and well-being. These dietary recommendations include calorie guidance and tips for a healthy, balanced diet. The Special K diet meets some of the criteria, but not all.

The Special K Diet places some control on the foods you eat and manages overall portions. These meal replacement diets primarily work by limiting the overall daily calorie intake. For instance, in one study, Purdue University researchers found that the participants eating cereal for two meals per day reduced their overall calorie intake by an average of at least 600 calories per day.

Taking in fewer calories than you use each day can help you achieve your weight loss goals, but you should achieve this reduction in a healthy and balanced way. Use this calorie calculator to determine your daily intake to meet your weight loss goals.

While some meal replacement diets provide a variety of healthy foods and focus more on controlled portions, the Special K Diet relies primarily on Special K products, which limits the variety of food and nutrients you consume. This is likely why the diet is only recommended for two weeks.

A Word From Verywell 

While the Special K diet promises losing up to six pounds in just two weeks, the diet was popular for about 10 years before sales of the products began to decline. The diet itself is not necessarily dangerous, but it doesn’t promote healthy or sustainable eating habits and is not viewed as a long-term weight loss solution by nutrition experts.

Following a regimented or highly restrictive diet with the goal of losing weight is often not the path to healthy, long-term weight loss or the answer to all of your health goals. Many factors like exercise, sleep, meditation, and more play a major role in your overall health. Aim to eat a balanced healthy diet that fits your lifestyle.

Remember, following a long-term or short-term diet may not be necessary for you and many diets out there simply don’t work, especially long-term. While we do not endorse fad diet trends or unsustainable weight loss methods, we present the facts so you can make an informed decision that works best for your nutritional needs, genetic blueprint, budget, and goals.

If your goal is weight loss, remember that losing weight isn’t necessarily the same as being your healthiest self, and there are many other ways to pursue health. Exercise, sleep, and other lifestyle factors also play a major role in your overall health. The best diet is always the one that is balanced and fits your lifestyle.

4 Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Gianturco P, Perez V. A meta-analysis of intervention trials examining the effects of a simple 2-week weight loss program on body weight and waist circumference. J Nutrition Health Food Sci. 2016;4(1):1-9. doi:10.15226/jnhfs.2016.00154

  2. Mattes RD. Ready-to-eat cereal used as a meal replacement promotes weight loss in humans. J Am Coll Nutr. 2002;21(6):570-7. doi:10.1080/07315724.2002.10719257

  3. Special K Red Berries Cereal. FoodData Central. U.S. Department of Agriculture.

  4. U.S. Department of Health and Human Services and U.S. Department of Agriculture. Dietary Guidelines for Americans, Ninth Edition.

Additional Reading

By Kelly Plowe, MS, RD
Kelly is a dietitian nutritionist with more than 10 years of experience in food and health communications. She specializes in intuitive eating.