Calories In vs. Calories Out Concept: Myths, Facts & FAQs
Work Wellness

Calories In vs. Calories Out Concept: Myths, Facts & FAQs

|Jun 12, 2024

When it comes to weight loss, the concept of "calories in vs. calories out" (CICO) often takes center stage. This principle, also known as energy balance, suggests that to maintain or lose weight, the calories consumed must be equal to or less than the calories burned. However, the simplicity of this formula has led to numerous myths and misunderstandings. In this blog, we'll explore the intricacies of CICO, debunk some common myths, and answer frequently asked questions to help you better understand this fundamental concept.

What is Calories In vs. Calories Out?

The term "calories in vs. calories out" refers to the balance between the calories you consume through food and drink (calories in) and the calories your body expends through basic physiological functions and physical activity (calories out). This balance determines whether you gain, lose, or maintain weight.

Calories In

"Calories in" represents the energy we obtain from the foods and beverages we consume. Each type of macronutrient—carbohydrates, proteins, and fats—provides a different amount of energy per gram. For example:

  • Carbohydrates: 4 calories per gram
  • Proteins: 4 calories per gram
  • Fats: 9 calories per gram

Calories Out

"Calories out" includes the energy your body uses to maintain basic functions (Basal Metabolic Rate or BMR), digest and process food (Thermic Effect of Food or TEF), and perform physical activities. BMR accounts for the majority of calories burned, while the rest comes from physical activities and TEF. Find out if standing burns calories and how a standing desk might contribute to your weight management goals.

The CICO Equation

The basic equation of CICO is: Weight Change = Calories In − Calories Out

If you consume more calories than you burn, you gain weight. Conversely, if you burn more calories than you consume, you lose weight.

Weight GainCalories In > Calories OutWeight Gain
Weight LossCalories In < Calories OutWeight Loss
Weight MaintenanceCalories In = Calories OutNo Weight Change

Calories In vs. Calories Out Myth

Despite its simplicity, the CICO model has sparked controversy and led to several myths. One of the most pervasive calories in and calories out myths is that all calories are created equal and that managing weight is solely about balancing the CICO equation.

Myth: All Calories Are Equal

While it's true that a calorie is a unit of energy, the source of those calories matters. Different foods have varying effects on metabolism, hunger, and hormones. For instance, 200 calories from a sugary soda will affect your body differently than 200 calories from a chicken breast.

Myth: CICO Ignores Nutritional Quality

CICO focuses on calorie quantity but doesn't address the nutritional quality of foods. Eating a diet rich in whole, nutrient-dense foods supports overall health and can aid weight management more effectively than simply counting calories from any source.

Myth: CICO Is the Only Factor in Weight Management

Weight management is influenced by numerous factors, including genetics, hormones, sleep, stress, and gut health. While CICO is a foundational principle, it's not the only determinant of weight loss or gain.

Calories In vs. Calories Out Myth


Why Calories In Calories Out Is Wrong

Critics argue that CICO oversimplifies the complex processes of human metabolism and fails to account for the qualitative differences in foods. Additionally, factors such as hormonal imbalances, metabolic adaptations, and psychological elements can influence weight management beyond mere calorie counting.

How Many Calories in a Chicken Breast?

A standard 3.5-ounce (100-gram) serving of cooked chicken breast contains approximately 165 calories. It's a high-protein, low-fat option ideal for those aiming to manage their calorie intake.

How Many Calories in a Cucumber?

Cucumbers are very low in calories. A 100-gram serving of raw cucumber with the peel contains about 16 calories. They are an excellent low-calorie snack choice.

Which Foods Are High in Calories?

High-calorie foods are typically rich in fats and/or sugars. Examples include:

  • Nuts and seeds
  • Avocados
  • Cheese
  • Dark chocolate
  • Processed snacks like chips and cookies

How Many Calories Should Be in Breakfast?

The ideal calorie intake for breakfast varies depending on your total daily calorie needs. Generally, breakfast should provide about 20-25% of your total daily calories. For a 2,000-calorie diet, this translates to 400-500 calories. Learn the difference between active and total calories to understand how various activities impact your energy expenditure.

How Many Calories Should You Eat in a Day?

Daily calorie needs vary based on age, sex, weight, height, and activity level. On average:

  • Adult women need 1,800 to 2,400 calories per day.
  • Adult men need 2,200 to 3,000 calories per day.

How Many Calories Should I Burn in a Workout?

The number of calories burned in a workout depends on the type, intensity, and duration of the exercise, as well as your body weight. For example:

  • A 155-pound person burns approximately 300 calories in 30 minutes of moderate-intensity cycling.
  • A 155-pound person burns about 450 calories in 30 minutes of vigorous-intensity running.

Compare whether the Stairmaster burns more calories than the treadmill for effective workout choices

Do Calories in Alcohol Count?

Yes, calories in alcohol count towards your daily intake. Alcohol contains 7 calories per gram, which is more than carbohydrates and proteins but less than fats. Be mindful of these "empty" calories, as they provide little to no nutritional value.

Is Calories In Calories Out True?

The CICO principle is fundamentally true in that energy balance affects weight change. However, it oversimplifies the complexity of human metabolism and doesn't account for factors like food quality, hormonal responses, and individual metabolic differences.

Does Calories In Calories Out Work?

CICO can work for weight management, but it should be integrated with considerations of food quality, nutritional balance, and individual health factors. A holistic approach that includes healthy eating, physical activity, and lifestyle modifications is more effective for sustainable weight loss and overall health.

Why Calories In Calories Out Is Wrong

Critics of CICO argue that it fails to consider the complexities of metabolism, hormonal regulation, and psychological factors that influence weight management. While CICO is a useful guideline, it is not a one-size-fits-all solution. Explore how many calories your body burns at rest to better understand your Basal Metabolic Rate (BMR).


The "calories in vs. calories out" concept is a fundamental principle of weight management but should be viewed as part of a broader approach to health and nutrition. Understanding that not all calories are equal and that various factors influence weight can lead to more effective and sustainable weight management strategies. By focusing on both the quantity and quality of calories, along with lifestyle and metabolic factors, individuals can achieve better health outcomes. Discover the calories burned standing vs sitting and how different postures affect your daily calorie burn

Remember, the journey to optimal health is personal and multifaceted. Use CICO as a guideline, but also pay attention to your body's unique needs and responses to create a balanced and healthy lifestyle.

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