What is the CICO Diet? Is It Healthy?

Written by Ahmed Zayed Helmy, MD, on March 17, 2021

Diet modifications paired with regular exercise are a fundamental component of a successful weight loss. A wide range of diet programs is available today and many of them take social media by storm. One of the most widely talked about eating patterns today is a CICO diet. It’s natural to wonder whether a popular CICO diet is safe, effective, and healthy. This post aims to give you the answers to inform you about the safety and efficacy of this diet. Read on to learn more.

What is the CICO Diet?

The term “CICO” stands for “Calories In, Calories Out” and it’s not a specific diet plan, book, or program endorsed by some athlete, fitness trainer, or nutritionist. In a nutshell, CICO is just a name for a well-known weight loss strategy that operates under the premise that you’ll lose weight if you consume a lower amount of calories than you burn. The main idea of this approach is that as long as you remain within a calorie range that’s in line with the body’s needs, you can eat whatever you want and still lose weight or maintain your current weight in a healthy range.

With the CICO diet, it doesn’t really matter what exercises you do or if you do any. Advocates of the CICO diet believe that as long as the equation regarding calories is okay, they will slim down. To achieve their goal, many men and women use calorie calculator apps so they can track calorie intake.

How Does the CICO Diet Work?

The CICO diet is straightforward. It relies on a basic equation where “calories in” refers to the consumption of foods and drinks and “calories out” refers to the number of calories we burn. In other words, “calories out” (also known as total daily energy expenditure or TDEE) is the energy your body uses during activity and resting. If you use more energy than you add, the body burns fat stores and uses them as fuel (1). That’s when weight loss occurs.

On the flip side, if TDEE is lower than the number of calories you consume, that’s when weight gain could happen. A growing body of evidence confirms that overweight and obesity are associated with decreased physical activity levels (2).

You see, the CICO diet is all about energy balance (3) where a person should focus on making energy intake lower than TDEE. Advocates believe that as long as you consume fewer calories than you burn off, regardless of what you eat, weight loss will ensue. But if you want to maintain a certain weight, then energy expenditure and consumption need to be equal.

As mentioned above, there is no specific diet plan to follow which gives people the liberty to eat a variety of meals.

How to Determine How Many Calories to Consume or Burn?

There is no specific formula for calorie consumption or energy expenditure that everyone should follow. The reason is simple; several factors determine how many calories you should eat during the day. They are (4):

Physical activity level (calories out)
Age
Height
Weight

To determine how many calories to consume, you need to think about energy expenditure first. Although in the CICO diet it doesn’t matter if you work out as long as calorie intake is lower than expenditure, you should still exercise regularly. Determine how many times a week you will exercise and the type of training you want to do. It can be strength training, cardio, playing sports, options are endless. Based on energy expenditure from workouts and physical activity goals you could set adequate calorie consumption goals. Many people use fitness apps and calorie calculator apps to define these goals easily.

Benefits of CICO Diet

When implemented properly, the CICO diet could offer a wide range of benefits. We’re going to discuss those advantages below.

Lower calorie intake

A major problem for many people nowadays is overeating. They tend to consume more calories than they burn. Food cravings are among the biggest obstacles on the road to weight loss for many people (5). CICO diet could help a person put an end to overeating and excessive calorie consumption.

Calorie restriction is often misunderstood. To most people, it means consuming a lower amount of calories than usual. It takes more than that. You see, calorie restriction is a practice of decreasing calorie intake by 30% to 40% while maintaining proper nutrition. It’s not just about reducing calorie intake, but doing so in a way you still consume nutrients such as healthy fat, carbs, protein, vitamins, minerals, antioxidants your body needs to function properly, support metabolism, and slim down.

When done properly, lower calorie intake has a wide range of health benefits including antidepressant effects, reduced oxidative stress, increases nitric oxide production, prevents atherosclerosis, aids management of blood pressure, and protects heart health (6, 7). Healthy calorie restriction can also support eye health, slows down the aging process, and improves memory performance (8, 9).

Weight loss

The most common reason people start with the CICO diet is to slim down. Indeed, this approach would work for weight loss when done right. For example, one study compared the effects of calorie restriction and a low-fat diet on weight loss. Findings showed a low-calorie diet led to a greater decrease in body fat percentage. Subjects in the calorie restriction group consumed fewer calories, fewer carbs, and the same amount of fat as participants in the low-fat diet group, yet they experienced more effective weight loss (10).

A study from the journal Nutrients found that calorie restriction improves body composition and lipid profile (11). Scientists investigated the roles of two kinds of calorie restriction on weight loss:

CR I – reducing daily caloric intake by 20% of TDEE
CR II – decreasing daily caloric intake by 30% of TDEE

When adjusted to the caloric needs of a participant, both approaches led to reductions in body mass and BMI improvement. CR II was more effective than CR I and it is more suitable for subjects with high body-fat content and people with elevated glucose, insulin, lipoprotein, and cholesterol levels.

Cost-effective and easy to implement

CICO diet doesn’t require focusing on certain foods only while eliminating others. It’s important to focus on the quality of calories you consume, but you do have the freedom to modify your diet without making it seem like a “punishment”. If you do it properly, you’ll be able to stick to the eating pattern. Also, unlike many other dietary approaches, this one is cost-effective. Since you have the freedom to modify your diet, it’s easier to incorporate it into your budget.

Risks of CICO Diet

Although the CICO diet has significant advantages, there are certain risks we need to address as well. The idea of calorie restriction is the foundation of CICO, but in some people, it may lead to unhealthy choices and subsequent health problems. If you severely cut down calorie intake or fail to implement CICO properly you risk developing nutrient deficiencies.

For example, a person who consumes unhealthy food (hoping to burn off calories in the gym) can experience nutrient deficiencies including low zinc levels, decreased antioxidant concentration (12), among other problems. Nutrient deficiencies can pave the way to a number of health problems including DNA damage, cancer, heart disease, osteoporosis, diabetes, weak immunity, just to name a few (13, 14, 15).

If you use calorie intake calculations as an excuse to stick to eating fast food, you may put yourself at risk of developing increased inflammation, decreased control of infection, higher rates of cancer, and increased risk of allergies and anti-inflammatory conditions (16).

Constant calorie deficits, when done inadequately, can make it difficult to maintain regular physical activity due to lack of energy (17). However, regular exercise is necessary for a successful weight loss and its maintenance. If you keep lowering calories and fail to exercise, you would adopt an unhealthy approach to weight loss and risk gaining even more pounds eventually.

Is the CICO Diet A Sustainable Weight Loss Approach?

The premise of calories in and calories out can easily be described as the backbone of weight loss. If you think about it logically, to slim down you do need to consume fewer calories than you burn during the day. The theory is one thing, but the actual weight loss is something else entirely.

You see, weight loss and metabolism are more complicated than calories in and calories out premise. Keep in mind that counting calories do not always lead to long-term weight loss. In the same way, it doesn’t always mean you’ll be able to maintain weight in a healthy range. What’s more, the CICO diet may lead to feelings of being deprived. As a result, a person may engage in disordered eating.

Since there’s more to weight loss than calories in and calories out, failing to slim down on the CICO diet could harm your confidence and self-esteem. When you’re counting calories believing you’re doing the right thing, failing to see results on the scale can lead to negative thinking. At that point you may start thinking weight loss is not going to happen for you i.e. motivation levels decrease significantly.

Moreover, we do not burn calories the same way every day. For instance, the body burns calories from carbs faster than those from protein and fat. That’s the reason you feel full for a longer time when consuming protein and (healthy) fat. However, the way of eating where you count calories on a daily basis promotes the notion that a person can eat too much as long as they plan to burn those calories off in the gym.

While calories are important we need to remember that not all calories are equal. The quality of those calories is much more important. Obtaining calories from fruits and vegetables or healthy meals are not the same as consuming the same number of calories from junk food.

It’s useful to keep in mind that the CICO diet is not just about drawbacks when implemented properly. Unlike other eating patterns, CICO is not restrictive. Many diets nowadays focus on the consumption of certain food groups while eliminating everything else. The human body needs a variety of nutrients that are available in different sources. Since CICO doesn’t involve avoiding certain foods, it could help a person slim down in a healthy way. That being said, it’s crucial to implement CICO properly and avoid considering it as a gateway to the consumption of unhealthy food as long as the equation is right.

Should You Try the CICO Diet?

The decision of whether or not to give the CICO diet a try is up to you. Even though the diet has many drawbacks, it could help jumpstart your weight loss. You can turn the CICO approach into success with wise decisions. Do not let the premise of eating any food you want as long as the calories are fewer than the calories you burn fool you. Make sure to eat a well-balanced diet rich in vitamins, minerals, protein, healthy fats, antioxidants, carbohydrates (from healthy sources), and other nutrients the body needs to support metabolism and help you slim down.

Combine CICO with healthy food choices and regular exercise to turn it into a success. Always keep in mind that not all calories are equal so their quality is vital. Instead of relying on fitness trackers that track how many steps you make during the day and calling it a day, you should strive to exercise at least three times a week.

The best thing to do is to consult your doctor if you plan to do CICO. Your healthcare provider can give useful advice on how to do it properly for the best results.

Healthy and Successful Weight Loss Tips

If you want to slim down, you need to do more than just count calories. You may want to incorporate these tips into your lifestyle:

Eat a well-balanced diet rich in vitamins, minerals, protein, healthy fats, fiber
Limit consumption or avoid unhealthy foods entirely
Exercise regularly
Stay hydrated
Get enough sleep
Avoid skipping meals
Eat from a smaller plate to control your portions
Adopt a positive approach to healthy food, don’t consider it a punishment
Think of diet and exercise as integral components of a healthy lifestyle, not a program to follow for a few weeks

Conclusion

CICO diet is a complex subject. Calories in and calories out are important for weight loss, but there’s a lot more to take into consideration e.g. quality of the calories we consume. When implemented properly, the CICO diet could help you slim down. But it shouldn’t be an excuse to eat junk food or avoid physical activity. Calorie restriction should still deliver all the healthy nutrients the body needs.