CICO For Weight Loss: The Most Important Concept To Know!

  • By: Tony Miller
  • Time to read: 8 min.

CICO For Weight Loss

What Is CICO For Weight Loss? CICO is short for “calories in, calories out.” It’s not a specific diet, but a concept. This is one of the most important things to know in weight loss.

Once you understand this, you will know how all diets can work, or why they didn’t work. It doesn’t matter if the diet is: Fasting, Keto, Paleo, low carb, fad diets, celebrity diet, etc.

For any diet to work, it must create a calorie deficit to achieve weight loss.


What Is CICO For Weight Loss?

The CICO (“calories in, calories out.”) concept is simple: Basically, if you eat fewer calories than your body uses daily, you’ll lose weight.

However, if you consume more calories than your body burns, you’ll gain weight.

It’s a fundamental rule to grasp how weight changes happen.

Energy balance, a vital principle of weight loss is another way to think about it. We highly recommend you also read – What Is Energy Balance In Weight Loss?

When your calorie intake is less than the calories your body burns through daily activities and metabolism, you create a calorie deficit. This deficit forces your body to tap into its energy reserves, like stored fat, leading to weight loss over time.

CICO Calories In, calories out 

Is CICO The Same As Calorie Counting?

No calorie counting, means tracking the exact calories you eat, such as with an app like MyFitnessPal.

CICO (“calories in, calories out.”) is a concept to understand how weight loss, or weight gain works.

They can work in together, but are not exactly the same thing.

While all the staff, editors, nutritionist and personal trainers here at AsetFit, we all agree that calorie counting is very effective for fat loss, but it is not for everyone.

Counting calories can be hard to do long term and not practical for some people.

However, we believe that people should get educated in nutrition and at least try calorie counting for a couple of weeks in their life.

This helps people understand the relationship between what they eat, portion size and then how it effects their weight loss journey. They aren’t reliant on new TikToc diets, or the latest celebrity / influencer diet on YouTube.

Knowledge is power in nutrition and for fat loss.


How Does CICO Work?

At its core, it means that to lose weight, you need to burn more calories than you consume.

Food is energy. Energy in food is measured in calories. (Or kilojoules.)

Make sure your eating is slightly less than what your body expends, you will then tip the scales in favor of weight loss.

Calories in and calories out, CICO can be thought as an “Energy balance”. This refers to the relationship between “energy intake” (calories acquired through food and beverages consumed) and “energy out” (calories utilized by the body to meet our daily energy needs).

This requires a combination of mindful eating, being aware of portion sizes, and making healthier food choices.

Watching what you put in your mouth makes the most impact for weight loss, but exercise can help the energy expenditure.


Practical Tips for CICO

So here are some weight loss tips for CICO.

  1. Calorie Tracking: As mentioned above counting calories isn’t the same as CICO or necessary, but it can help understanding nutrition. At least try it for two to three weeks. Use a food journal, app, or website to keep track of your daily calorie intake and ensure you stay within your target calorie range.
  2. Balanced Diet: Focus on a well-balanced diet that includes a variety of nutrients, such as lean proteins, whole grains, fruits, vegetables, and healthy fats. Protein helps retain muscle mass when dieting and makes you feel fuller.
  3. Be Mindful of Portions: Pay attention to portion sizes to avoid unintentionally overeating, and try not to eat until you are overly full.
  4. Regular Exercise: Incorporate regular physical activity into your routine to increase your calorie expenditure and support weight loss. Weight training will help how your body composition and is recommended as part of your exercise program.
  5. Meal Prep: Planning your meals and Meal Prep for the week can help you stay on track when life gets hectic.
  6. Stay Consistent: Weight loss takes time and effort. Be patient and stay consistent with your CICO approach to see lasting results.
  7. Train Small Habits: Focus on making small, but sustainable changes to your lifestyle rather than resorting to extreme diets or restriction. (Example, try just doing one or two pushups a day. Then eventually try for some more, three or four a day.)
  8. Watch Hidden Calories In Drinks: Energy drinks, Pop Sodas, sports drinks, alcohol, and smoothies can have a lot of calories in them. Sometimes as much as a meal. Try diet sodas, mineral waters or just good old fashioned H2O instead.
  9. Get Educated: The more you understand nutrition and exercise, the less likely you will be influenced by fad diets, expensive fat loss supplements that don’t work and myths. Take control of your weight through knowledge.

Consult with a healthcare professional or a registered dietitian before starting any diets or exercise regime.

You might be interested in – Why Doesn’t Energy Balance Work In Weight Loss?


High protein salad with turkey slices

Will I lose weight with CICO?

Yes, CICO (calories in, calories out) is a proven theory for weight loss. By creating a calorie deficit, you can achieve weight loss over time.

Regardless of what diet you try, to lose weight you have to be in a calorie deficit!


What are the problems with CICO?

While CICO works and is an effective principle for weight loss, some people may struggle with putting it into actual practice.

People underestimate the calories they consume.

Tracking calories in, isn’t one hundred percent accurate and long-term adherence is hard and not practical.

Food labels may give an average and also seasonality, ingredients used, actual weight of the food, can vary from one product to another and affect the calorie count. However that doesn’t mean we shouldn’t be aware of what we eat.

Also tracking calories out (energy out) is extremely difficult, if not impossible to do accurately. (You would have to be monitored by scientist twenty four hours a day. While you sleep, move, work, fidget and exercise.)


What is the CICO formula?

The CICO formula is simple: you need to consume fewer calories than your body burns to create a calorie deficit.


What can you eat on CICO?

There are no strict food restrictions on CICO. You can eat a variety of foods, but it’s essential to focus on a balanced diet with healthier choices.

Avoid specific diets that restrict certain food types.

Choose a wide variety of vegetable and fruits, whole-grains, fish, healthy fats, lean proteins, dairy, etc.

Minimize your junk food and high calorie drinks.

Dietary Guidelines for America


How do I start the CICO diet?

To start CICO, begin by calculating your daily caloric needs and set a target calorie intake that is lower than what your body burns.

Educate yourself in nutrition by looking at the nutritional food label on the back of packets and see how many calories per serve. Also look at the macro-nutrients in the food. (Protein, fat and carbohydrates.)


Why am I not losing weight on CICO?

If you are not losing weight on CICO, it could be due to underestimating calorie intake, overestimating calorie burn, or other factors affecting weight loss.


How many calories should I eat a day on CICO diet?

The number of calories you should eat on a CICO diet depends on factors like age, gender, weight, activity level, and weight loss goals.


Does CICO slow metabolism?

A drastic and prolonged calorie restriction may lead to a temporary slowdown in metabolism, but regular adjustments to your calorie intake can help avoid this.


What is the 80 20 rule calorie deficit?

The 80-20 rule suggests that weight loss is primarily influenced by calorie intake (80%), while exercise and other factors play a smaller role (20%).

This is a general idea though and not really set in stone, but it reflects the importance on what you put in your mouth, is more important than trying to exercise it off.

An old saying ‘You can’t out-train a bad diet’, is very true.


How to eat 1,200 calories a day without starving?

Some people use the CICO idea with a maximum of 1,200 calorie target for the day, but wonder how to do it without feeling too hungry?

Eating 1,200 calories a day can be achieved by choosing nutrient-dense, filling foods, and distributing meals and snacks throughout the day.

Certain foods with fiber, like vegetables, wholegrains and protein in lean meats can fill you up more.

Foods like junk food that has empty calories that don’t have much nutritional value. These foods are generally high in calories and also easy to overeat. Have you tried just having one potato crisp?


Does it matter what you eat on CICO?

While calorie balance is essential for weight loss, the quality of the foods you eat affects overall health and well-being. Opt for nutritious choices within your calorie budget.


What is the CICO rule?

The CICO rule is the principle that weight loss occurs when you consume fewer calories than your body expends.


How accurate is CICO?

CICO is a sound concept for weight loss, but the accuracy depends on precise calorie tracking and accounting for individual metabolic variations.

As mentioned, tracking calories in, isn’t very accurate. However it gives you a good idea and ball park figure to work with and adjust.



CICO for weight loss is a powerful tool to help you achieve your weight loss objectives.

By understanding the concept of calories in and calories out, and making mindful choices about your diet and activity levels, you can take control of your weight and embark on a healthier journey towards a happier and fitter you.

Remember, consistency, knowledge and balance are key to long-term success with CICO for weight loss.


Resources, References And Extra Reading

What Foods Are Low Calorie? 20 Delicious Foods & Snacks

20 Healthy Foods To Buy At Trader Joe’s

The Muscle and Strength Nutrition Pyramid. By Eric Helms.

Fat Loss Forever, How To Lose Fat and Keep It Off. By Peter Baker and Layne Norton PH.D

The Renaissance Diet, A Scientific Approach to Getting Leaner and Building Muscle. By Dr. Mike Israetel, with Dr. Jen Case and Dr. James Hoffman.

Burn The Fat Feed The Muscle. By Tom Venuto

Specialist in Fitness Nutrition. John Berardi, PH.D and Ryan Andrews, MS/MA, RD.