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Energy balance & calorie requirements: How much energy does your body need?

Why do some people seem to lose weight effortlessly, while others maintain or gain weight despite similar diets? The answer often lies in the energy balance; the interplay between energy intake and energy expenditure.

Understanding how much energy your body truly needs can help you consciously regulate your weight and stay healthy in the long term. In this article, you will learn how to determine your daily calorie needs, what factors play a role, and how you can balance your energy with diet, exercise, and smart measuring aids.

Table of Contents:

What does energy balance mean?

Energy balance describes the relationship between energy intake (through food and drink) and energy expenditure (through basal metabolic rate and activity).

If the balance is positive, you take in more energy than you expend, and your body stores the excess energy as fat reserves.
If it is negative, the body taps into these reserves to provide energy.
An equal energy balance means that energy intake and expenditure are the same, and you maintain your weight.

This equilibrium is not a fixed value but depends on many individual factors. Therefore, the goal should not only be to hit the "right" number of calories but to develop a better understanding of your own body and its energy needs.

What are calories?

Calories are the unit of measurement for energy. They indicate how much energy a food provides and how much the body can derive from it. In everyday life, we usually talk about kilocalories (kcal) or kilojoules (kJ). The body uses this energy for all sorts of processes – from breathing to movement.

How much energy does the body need?

Daily energy needs vary individually and depend on various factors. Even though a general number cannot be given, there are guidelines and calculation bases that provide orientation.

What does the body use energy for?

Our body uses energy for much more than movement or sports. Even at rest, numerous processes occur that require energy. These include:

Breathing and cardiovascular function
Regulation of body temperature
Metabolic processes such as digestion and cell construction
Brain activity and nerve functions
Regeneration and cell repair during sleep

These basic functions ensure our survival and form the so-called basal metabolic rate – the energy expenditure your body has even without physical activity.

What does energy need depend on?

How much energy the body needs in total and how high your daily calorie needs are depends on various individual factors:

Age: As age increases, energy needs decrease because muscle mass and metabolic rate decline.
Gender: Men usually have a higher basal metabolic rate because they have more muscle mass.
Body size and weight: Larger and heavier individuals require more energy.
Activity level (PAL value): The more active the daily routine, the higher the energy expenditure.

Daily energy needs are a calculation of the basal metabolic rate and the active metabolic rate.

Basal Metabolic Rate and Active Metabolic Rate

Basal Metabolic Rate (BMR)

The basal metabolic rate (BMR) describes the amount of energy your body needs in a complete resting state to maintain all vital functions. It constitutes the largest part of daily energy expenditure – about 60 to 75%.

The basal metabolic rate strongly depends on body composition: people with more muscle mass also consume more energy at rest, as muscles perform metabolic work even when idle. Fat tissue, on the other hand, consumes significantly less energy. Age, gender, size, and hormone balance also influence the basal metabolic rate.

Active Metabolic Rate (AMR)

The active metabolic rate (AMR) describes the additional energy needs through physical activity. This includes sports, physical work, or everyday activities like walking or housework. It varies greatly depending on lifestyle and can significantly increase total expenditure.

For orientation, so-called PAL values (Physical Activity Level) indicate the activity level: ^*1

1.2–1.3: little movement, predominantly sedentary or lying lifestyle (e.g., bedridden or immobile persons)
1.4–1.5: sedentary work with little or no physical activity in leisure time (e.g., office workers)
1.6–1.7: predominantly sedentary work with occasional walking or standing (e.g., students, lab technicians, assembly line workers)
1.8–1.9: predominantly walking or standing work (e.g., salespeople, waiters, craftsmen)
2.0–2.4: physically demanding work or very active lifestyle (e.g., construction workers, competitive athletes)

Calculating total energy needs

To calculate daily calorie needs, the following simplified formula applies:

Total expenditure = Basal Metabolic Rate x Activity Factor (PAL value)

This value indicates how many calories are needed to maintain current weight. To gain weight, energy intake should be slightly higher, to lose weight, slightly lower.

Guidelines for daily calorie needs

The German Nutrition Society (DGE) provides guidelines ^*2 that vary by age, gender, and activity level. An adult needs an average of between 1,800 and 3,000 kilocalories per day – depending on gender and activity. These values serve as orientation but do not replace individual calculation.

Calorie needs for losing or gaining weight

To gain weight, the energy balance must be positive – more calories must be consumed than expended. Conversely, to lose weight, a negative balance is needed. This can be achieved through more exercise or adjusting the diet, ideally through a combination of both. Besides quantity, the quality of food also plays a role: a balanced diet with all essential nutrients supports the body in staying healthy and maintaining the desired weight in the long term. Learn more in our article "Balanced Diet."

Keeping track of your energy balance

For a healthy energy balance, it is helpful to regularly observe your body and weight development. Beurer diagnostic scales, such as the BF 990, offer valuable support. They measure not only weight but also body fat percentage, muscle mass, visceral fat, and other metrics. Thanks to Bluetooth® and WIFI connectivity, all data is automatically transferred to the "beurer HealthManager Pro" app. This allows you to track progress in training, dietary changes, or general health monitoring in a targeted manner.

Healthy weight development instead of diet focus

Health does not only mean losing weight. Those who want to gain or maintain weight also benefit from understanding their energy balance. Conscious nutrition, regular exercise, and knowledge of personal calorie needs promote long-term well-being rather than forcing short-term successes. The goal is not an ideal weight, but a body in which you feel comfortable, fit, and balanced.

^{*1 https://www.dge.de/gesunde-ernaehrung/faq/energiezufuhr/#c2969}
^{*2 https://www.dge.de/wissenschaft/referenzwerte/energie/}