On the cereal diet, you replace two meals per day with cereal and milk.
Though the diet has been around for a while, it has recently surged in popularity.
It seems to be effective for short-term weight loss and can be rich in fiber and whole grains. Yet, it may also be high in sugar and excessively restrictive.
Here’s a comprehensive review of the cereal diet to help you decide whether it’s right for you.
RATING SCORE BREAKDOWN
- Overall score: 2
- Fast weight loss: 2.5
- Long-term weight loss: 1
- Easy to follow: 2.5
- Nutrition quality: 2
BOTTOM LINE: On the cereal diet, you replace two meals per day with cereal and milk while keeping your third meal and snacks low in calories. It may aid short-term weight loss but is not sustainable or nutritionally balanced.
The cereal diet gained mainstream popularity from the “Special K Challenge.”
Special K cereal has long been marketed as a healthy food that can help you lose weight, and some boxes of the cereal even had the instructions for the two-week challenge printed on them.
However, Kellogg’s — Special K’s parent company — no longer promotes this challenge or the cereal diet.
On this diet, you replace your breakfast and lunch with a serving of whole-grain cereal and skim or low-fat milk.
Your dinner and snacks should be small, low in calories, and contain a lean protein, as well as whole grains, fruits, and vegetables.
Furthermore, some diet challenges involve eating nothing but cereal with milk for an entire week. Yet, it’s best to avoid these challenges, as they can be extremely low in calories and protein and may cause fatigue, decreased focus, and mood alterations (1).
On the cereal diet, you replace two meals per day with a serving of whole-grain cereal and low-fat milk. One popular version was the “Special K Challenge.”
The cereal diet is relatively easy to follow.
Simply replace both breakfast and lunch with a serving of cereal and 1/2–2/3 cup (120–180 ml) of skim or low-fat milk. Preferably, the cereal should be low in added sugars and made from whole grains, such as Special K, Total, or plain Corn Flakes.
For dinner, you’re advised to choose a meal that is rich in fruits, vegetables, and whole grains, as well as low in fat and calories — ideally 450 or fewer calories.
Examples include a grilled chicken salad with vinaigrette dressing and fresh fruit, or brown rice with salmon and seasoned vegetables.
You’re also allowed two snacks per day, each providing 100 or fewer calories.
If you follow this diet closely, you likely consume about 1,200–1,500 calories per day, which should result in weight loss for most people. Calories will depend on the cereal you choose and how much of it you eat.
It’s recommended to eat one serving of your chosen cereal at breakfast and lunch. The serving size is defined by the nutrition label on the box and is commonly 2/3–1 cup (about 28–42 grams).
Most people follow the cereal diet for five days to two weeks. You should not follow the diet longer than that, as it’s difficult to adhere to, may be low in calories and protein, and could result in food cravings (2, 3, 4).
To follow the cereal diet, replace breakfast and lunch with a serving of whole-grain cereal with low-fat milk. Your supper and snacks should be low in calories and contain lean protein, whole grains, and fruit or vegetables.
Many people have lost weight on the cereal diet due to the calorie restriction it involves (5).
One study in 24 adults on the 2-week “Special K Challenge” found that participants slashed their intake by about 600 calories per day and lost weight and fat mass (2).
However, this study was sponsored by Kellogg’s — the makers of Special K — so the results may be biased (2).
Moreover, the weight loss may not be sustainable. Significantly decreasing your calorie intake by following a restrictive diet like the cereal diet has been shown to make it more difficult to lose weight and keep it off in the long run (6, 7, 8).
For instance, levels of leptin, a hormone that tells your body when you have had enough food, decrease when you restrict your calories. Decreased leptin levels can lead to increased hunger and food cravings (3, 4).
Additionally, when you suddenly decrease the number of calories you eat, your body compensates by decreasing your metabolic rate, or the number of calories you burn (9).
You may lose weight on the cereal diet as a result of calorie restriction. Still, you may not be able to keep the weight off long term due to some of the effects that calorie restriction has on your metabolism.
If you choose whole-grain cereals, then following the cereal diet is a great way to increase your whole-grain and fiber intake.
Higher whole-grain intake is associated with better health outcomes and a decreased risk of death from all causes (12).
In fact, in one review of studies with over 1 million participants, every 28 grams of whole grains consumed per day were associated with a 9% decrease in risk of death from any cause and a 14% lower risk of death from heart attack (12).
The fiber in whole grains promotes healthy digestion and can help you manage your weight (13).
Yet, it’s important to note that simply increasing your intake of more nutrient-dense, whole foods like vegetables and fruits will offer the same benefit.
The cereal diet can be rich in whole grains and fiber, which are associated with better health outcomes, including a lower risk of death from all causes and increased weight loss.
In addition to being a restrictive diet plan that may not help you keep weight off long term, the cereal diet has other downsides to consider.
Added dietary sugars are linked to several health problems and should be limited to less than 5% of your total calorie intake (14).
The cereal diet can be very high in sugar. Even if you choose a cereal that does not taste sweet, most products contain added sugar in some form.
What’s more, cereal and milk are both high in carbs, which break down into sugars that provide energy for your body.
Choosing low-sugar cereals, such as original Special K, is a better option than sugary cereals like Fruit Loops or Frosted Flakes.
The cereal diet can be low in protein, healthy fat, and overall calories unless it’s very carefully planned.
Your body needs protein to build and maintain your muscles, tissues, and enzymes — protein-based compounds that direct several bodily functions. Like fiber, protein also helps keep you feeling full (18, 19).
In addition, the cereal diet is touted as a low-fat diet. You’re encouraged to use skim or low-fat milk to keep your calories low.
Still, while fat has more calories per gram than protein or carbs, recent research suggests that dietary fats, including saturated ones, can be part of a healthy diet and may even help you lose weight because they’re filling (15, 20, 21, 22).
The cereal diet is high in sugar, which may make weight loss more difficult. Moreover, it can be low in protein and healthy fats.
On the cereal diet, you primarily eat cereal and milk. Still, it encourages eating lean meats, fruits, vegetables, and whole grains at snack- and dinnertime.
Here is a list of foods you can eat on the cereal diet:
On the cereal diet, you’re encouraged to choose whole-grain cereal and low-fat milk in addition to lean proteins, whole grains, fruits, and vegetables.
The following foods should be avoided on the cereal diet, as they’re high in fat, refined sugars, and calories:
While on the cereal diet, you should avoid foods that are high in fat, refined sugar, or calories, including cakes, fried foods, and full-fat dairy products.
Below is a 3-day sample menu for the cereal diet, which includes two snacks per day.
The above 3-day sample menu for the cereal diet includes two meals per day of cereal and milk, a third balanced meal, and two low-calorie snacks each day.
On the cereal diet, you eat cereal with milk twice a day. Your third meal and snacks should be low in calories.
The diet is rich in whole grains and fiber and likely aids short-term weight loss if done correctly.
Yet, it can be high in sugar and low in calories, protein, and healthy fats. If you’re looking to achieve lasting weight loss, other, more balanced diet plans may be a better and more sustainable choice.