Energy Balance and Energy Requirements
Every person has a very specific energy or calorie requirement. This requirement can vary depending on body composition, gender, activity level and age.
The energy content of a food can be measured precisely by its heat of combustion and is expressed in calories. One kilocalorie (kcal) is the amount of energy needed to heat 1 litre of water by 1°C.
To keep track of a person's food requirement, or more precisely their energy requirement, you need to know the energy content, in other words the calorific value, of the individual nutrients:
1 g protein = 4.1 kcal = 17 kJ (released when burned)
1 g fat = 9.3 kcal = 39 kJ
1 g carbohydrates = 4.1 kcal = 17 kJ
1 g alcohol = 7.1 kcal = 30 kJ
1 kcal corresponds to 4.1855 kJ (kilojoules) --> 1 kcal ~ 4.2 kJ
1 kJ corresponds to 0.239 kcal --> 1 kJ ~ 0.24 kcal
Energy requirement
Your total daily energy requirement is made up of:
- Basal metabolic rate
- Working metabolic rate (muscular work)
- Leisure-time metabolic rate
- Thermogenesis after food intake
- Energy required for growth
Basal metabolic rate is the energy expenditure of a person lying down in a relaxed state, measured exactly twelve hours after the last meal, at an ambient temperature of 20°C, over a period of 24 hours. Basal metabolic rate is made up of 40% from the energy used to maintain brain, liver, heart, circulatory and kidney function and breathing, and 60% from heat production. Basal metabolic rate depends on age, gender, body surface area, hormonal factors, illness, muscle mass proportion, and so on. A higher basal metabolic rate correlates closely with the amount of fat-free body mass (the more fat-free body mass, the higher the basal metabolic rate).
You can estimate your basal metabolic rate using the following formula:
Women: basal metabolic rate (per day) = body weight in kg x 0.9 x 24
Men: basal metabolic rate (per day) = body weight in kg x 24
Because of their greater muscle mass, men have a higher basal metabolic calorie requirement than women.
Thermogenesis is the term for the conversion of food energy through combustion, which, among other things, generates heat. The degree of thermogenesis appears to be innate and barely influenceable.
In infants and children, energy requirements can be relatively high because of growth.
Weight gain and being overweight are the result of a positive energy balance. The body is supplied with more energy than it uses.
There are people who consume significantly more calories than their weight and total energy expenditure would suggest, yet still maintain their ideal weight. Conversely, there are many obese or overweight people who keep their body weight constant, or even increase it, despite eating less. When the daily energy requirement is exceeded, this excess energy is not automatically stored as fat deposits; instead, the body has the ability to get rid of this energy again through "extra burning". The body thus protects itself against weight gain through increased thermogenesis.
Balanced Eating and Drinking
An important cornerstone of a healthy lifestyle is the ability to regulate tension and relaxation. Our everyday life is often shaped by rush and stress, which makes it all the more important to take conscious time out to rest and recharge. This can happen in many different ways: spontaneously, systematically, through targeted relaxation techniques, leisure activities, enough sleep, physical activity, socialising, and so on.
Balanced Nutrition
Three balanced main meals – breakfast, lunch and dinner – give your body the energy it needs on a regular basis. This traditional meal rhythm can be adapted to your appetite and personal habits. For example, a main meal can be replaced by one or two smaller meals. Or the main meals can be supplemented with snacks (in the morning, afternoon or evening). Snacks provide a small energy boost when the time between meals is very long. They prevent sudden hunger pangs and offer an extra way to make your diet more varied. Everyone has to find their own rhythm, but above all should avoid constantly nibbling on something.
Stop what you're doing, sit down comfortably and take the time to enjoy your food in peace. These principles also apply to meals eaten away from home. This way, the break becomes more restful, you eat more mindfully and notice the feeling of fullness better.
Source: Nutrition and Sport Script, update Fitness AG
