Estimated Energy Requirement Calculator
Calculate your daily energy requirements based on your age, weight, height, activity level, and gender.
Enter Your Information
Table of Contents
Understanding Estimated Energy Requirements
Estimated Energy Requirement (EER) is a crucial concept in nutrition science that represents the average dietary energy intake predicted to maintain energy balance in a healthy individual. Energy is essential for sustaining the body's various functions, including respiration, circulation, physical work, and protein synthesis. This energy is derived primarily from dietary carbohydrates, proteins, fats, and to a lesser extent, alcohol.
Components of Energy Expenditure
To understand EER, it's important to recognize the different components that make up your total energy expenditure:
1. Basal Metabolic Rate (BMR)
BMR reflects the energy needed to sustain metabolic activities of cells and tissues, plus the energy needed to maintain blood circulation, respiration, and other vital functions while awake, in a fasting state, and resting. BMR represents about 60-75% of total energy expenditure for most individuals.
2. Thermic Effect of Food (TEF)
TEF refers to the increased energy expenditure caused by food consumption, including digestion, absorption, transport, and storage of nutrients. TEF accounts for approximately 10% of total energy expenditure for a mixed diet.
3. Physical Activity Energy Expenditure
This is the most variable component, which encompasses planned exercise and non-exercise activities like fidgeting, maintaining posture, and other spontaneous movements. Physical activity typically accounts for 15-30% of total energy expenditure but can be much higher in very active individuals.
4. Additional Energy Needs
In specific life stages, additional energy is needed for growth and development (children), tissue deposition during pregnancy, and milk production during lactation.
Energy Balance and Weight Management
Energy balance is achieved when energy intake equals energy expenditure:
- When energy intake exceeds expenditure, the excess is stored, primarily as fat, leading to weight gain
- When energy expenditure exceeds intake, the body mobilizes energy stores, primarily adipose tissue, leading to weight loss
- Maintaining a stable weight indicates energy balance
Unlike other nutrients, there is no Recommended Dietary Allowance (RDA) or Tolerable Upper Intake Level (UL) for energy. This is because excess energy intake leads to weight gain rather than being eliminated from the body, and inadequate energy intake leads to weight loss.
Factors Affecting Energy Requirements
Several factors influence individual energy requirements:
Body Size and Composition
Larger individuals and those with more muscle mass have higher energy needs
Age
Energy requirements generally decline with aging due to reduced BMR and activity levels
Sex
Men typically require more energy than women due to differences in body composition
Physical Activity Level
The most variable and modifiable factor affecting energy needs
Life Stage
Growth, pregnancy, and lactation increase energy requirements
Genetics and Metabolism
Individual variations can affect energy requirements by 10-20%
Health Implications of Energy Imbalance
Maintaining appropriate energy balance is important for health. Chronic excess energy intake leads to overweight and obesity, which are associated with increased risk of type 2 diabetes, cardiovascular disease, certain cancers, and other health problems. Conversely, chronic energy deficit can lead to underweight, malnutrition, reduced immune function, and other health concerns.
Using EER in Practice
The EER equations provide a starting point for estimating energy needs, but individual requirements may vary. For weight management, it's important to monitor body weight over time and adjust energy intake accordingly. For weight maintenance, consume calories equal to your EER. For weight loss, create a modest energy deficit (500-1000 calories below EER), and for weight gain, consume more than your EER.
The EER is continuously being refined through research to improve its accuracy across different populations and life circumstances. The most recent updates include improved calculations for diverse populations, consideration of the effects of aging, and better accounting for different physical activity levels.
Scientific Advancements in Measuring Energy Expenditure
Doubly Labeled Water (DLW) has revolutionized the measurement of energy expenditure in free-living conditions. This gold standard method involves consuming water labeled with stable isotopes of hydrogen and oxygen, then tracking their elimination rate from the body to precisely calculate carbon dioxide production and energy expenditure.
Recent Research Findings
- Total energy expenditure varies significantly across populations, with factors like age, sex, body weight, and activity level accounting for 70-80% of this variation
- Physical activity level coefficients are not constant but vary across age groups, especially during the first 20 years of life
- Recent studies indicate that systematic misreporting of energy intakes underlies differences between self-reported intakes and actual energy requirements
- The relationship between weight change and chronic disease risk is complex, with evidence most consistent for an association between weight change and diabetes risk
- Weight cycling (repeated cycles of weight loss and regain) may promote greater subsequent weight gain through adaptive thermogenesis
2023 Updates to EER Calculations
The most recent Dietary Reference Intakes for Energy (2023) made two major changes to EER calculations:
- The calculations are now more inclusive, considering the general population including those with overweight, obesity, and chronic diseases, rather than just the "generally healthy" population
- The data sources for DLW were expanded to include more diverse population groups
These refined equations now better account for factors such as the age dependency in physical activity levels and provide more accurate energy requirement estimates across different life stages and diverse populations.
Note: While the EER calculations provide valuable guidelines, individual energy needs can still vary by approximately ±10-20% from the calculated values. Personal experimentation with careful monitoring of weight changes remains essential for effective energy management.
What is EER?
Estimated Energy Requirement (EER) is the average dietary energy intake that is predicted to maintain energy balance in a healthy adult of a defined age, gender, weight, height, and level of physical activity. It includes:
- Basal Metabolic Rate (BMR)
- Physical activity
- Thermic effect of food
- Growth and development (for children and adolescents)
How to Calculate EER
EER is calculated using the Institute of Medicine (IOM) equations:
For women: 354 - (6.91 × age) + PA × [(9.36 × weight) + (726 × height)]
Activity Level Multipliers
Sedentary (PA = 1.0)
Little or no exercise, desk job
Low Active (PA = 1.11)
Light exercise 1-3 days/week
Active (PA = 1.25)
Moderate exercise 3-5 days/week
Very Active (PA = 1.48)
Hard exercise 6-7 days/week
EER - Practical Examples
Example 1 Sedentary Office Worker
A 30-year-old male, 175cm tall, weighing 70kg with a sedentary lifestyle.
EER = 662 - (9.53 × 30) + 1.0 × [(15.91 × 70) + (539.6 × 1.75)] = 2,450 calories
Example 2 Active Athlete
A 25-year-old female, 165cm tall, weighing 60kg with an active lifestyle.
EER = 354 - (6.91 × 25) + 1.25 × [(9.36 × 60) + (726 × 1.65)] = 2,850 calories