How Many Calories Should I Eat In A Day?
Calorie requirement, daily requirement, and basal metabolic rate: Especially when it comes to losing weight, you hear these words constantly. But what are calories anyway and what is our daily requirement? EAT SMARTER explains what you need to know about calories, how to calculate your personal calorie consumption, and shows you five tricks on how to save extra daily calories!
How Many Calories Should I Eat In A Day?
In reality, calories or more specifically kilocalories (kcal) are a relatively obsolete unit of measurement for the amount of energy that our body burns and that we take in again through food in the form of carbohydrates, fats, and proteins every day.
The nutrients in carbohydrates, fats, etc... are broken down and utilized in the digestive tract. This releases energy, which we measure in calories or kilojoules.
One calorie is equal to 4.18 kilojoules. In the scientific field, the kilocalorie has long since been replaced by joules, but in everyday life, we still use calories as our main unit of measurement.
Roughly estimated, men up to the age of 50 should consume about 2,000 calories per day and women about 1,800 calories.
In theory, for successful weight loss, this means that you simply need to consume fewer calories per day than you burn, and the pounds will start to drop.
What is the daily calorie requirement?
The daily calorie requirement of a person is made up of the basal metabolic rate (BMR) and the active metabolic rate (AMR). These both result in energy conversion and thus approximately the number of calories that our body burns per day and needs.
Basal metabolic rate:
The basal metabolic rate is the amount of energy that the body needs to maintain all vital functions at complete rest, at a room temperature of 82 degrees Fahrenheit on an empty stomach. Each person’s BMR is strongly dependent on sex, age, height, and physique.
Women generally have a lower basal metabolic rate than men because they have a lower proportion of muscle mass in relation to fat mass. The BMR is expressed in calories per day (i.e. 24 hours).
Basal metabolic rate = 1 calorie (1.1 for men) x body weight (in kg) x 24
Active metabolic rate:
The active metabolic rate describes the energy consumption of physical activities and processes that take place in addition to the basal metabolic rate. This includes any muscle activity (for example, walking or sitting), the energy required for growth in children and adolescents, the digestive activities of our body, and the energy we use to regulate our body heat.
The AMR is expressed in PAL (physical activity level) and is defined for any type of work or sport.
In addition to the daily calorie requirement, the Body Mass Index (BMI) is also a useful indicator to help you lose weight. Our expert ecotrophologist Kirsten Sellmer explains how meaningful this is and what you should look out for in the Body Mass Index:
"The BMI is usually used as the decisive criterion in medicine and in studies on overweight and obesity. However, it should not be considered as the only value. The decisive factor is the composition of the body - how much muscle mass is present and how much fat mass? Here the BMI reaches its limits: If, for example, a rather small man is very well trained and has a lot of muscle mass, he may have a BMI of 26, so he is considered slightly overweight. Yet he only has a body fat percentage of ten percent. The fat distribution of the body must be taken into account: Is there more fat in the abdominal area? Abdominal fat is significantly more problematic than fat under the skin or on the hips. This is because it is not only pure energy storage but also produces messenger substances in the body that promote the development of chronic diseases.”
Of course, you don't lose weight because you know how many calories you need per day or what your body mass index is. But it can't hurt to have a rough idea of your calorie requirements and BMI to develop a feeling for how many calories you can or should consume.
This is how to calculate your required calories per day:
As already mentioned, the daily calorie consumption is composed of basal metabolic rate and active metabolic rate. In addition, there are variables such as gender, weight, age, and height (in cm).
Calculate your approximate basal metabolic rate using the following formula:
For men: Basal metabolic rate = body weight (kg) * 24
For women: Basal metabolic rate = 0.9 * body weight (kg) * 24.
In addition to this, there is also the active metabolic rate, i.e. everything we need over and above our energy level for vital processes in the body. The metabolic rate is defined for any physical activity and is, as already mentioned, expressed in PAL (physical activity level).
In the following table you will find the defined values for different levels of physical activity according to the DGE (German Society for Nutrition):
| Physical Activity Per Day | PAL Value |
| Frail, immobile, bedridden people (exclusively sedentary or recumbent lifestyle) | 1.2- 1.3 |
| Office staff, precision mechanics (exclusively sedentary work with little or no strenuous leisure activity) | 1.4- 1.5 |
| Laboratory assistants, students, assembly line workers, teachers (sedentary work with additional energy expenditure for walking and standing activities, little or no strenuous leisure activity) | 1.6- 1.7 |
| Shop assistants, waiters, mechanics, craftsmen (mainly walking and standing work) | 1.8- 1.9 |
| Construction workers, farmers, forestry workers, miners, competitive athletes (physically demanding professional work or very active leisure activity) | 2.0- 2.4 |
To calculate your calorie consumption, multiply your basal metabolic rate by the PAL value corresponding to your daily physical activity. For example, if a man with a basal metabolic rate of 2040 calories is an office worker, his actual requirement would be 2856 calories per day (2040* 1.4= 2856).
However, this calculation method does not include age and weight, metabolism and personal eating habits, or other physical and psychological factors. Furthermore, it does not work for women who, due to pregnancy, have a slight weight gain and therefore have an increased energy intake.
For more precise calculations you should have your calorie consumption calculated by a specialist, this is usually done using indirect calorimetry.
Five strategies to help you cut down on calories:
Take in fewer calories than you burn and lose those pounds? Unfortunately, this is not enough. If you only pay attention to the calorie content of your food and simply eat less, but still mainly eat fat, sugar, and processed meals, you will not be successful in the long run.
To lose weight in a healthy and sustainable way, it is important to eat a balanced and nutritious diet and to also drink a lot of water. Here’s how to eat in a balanced diet and still cut some calories:
1. Eat foods high in protein
Eating high-protein foods helps you to save calories. This is due to food-induced thermogenesis. This effect represents the energy consumption that occurs during digestion, storage, and the transport of food. And this thermal effect is much higher when you eat protein than carbohydrates or fat.
Besides the extra calories that your body burns, protein-rich food also helps to counteract the breakdown of muscle mass and keep your metabolism going. As a result, you lose more fat than muscles and keep your new lighter weight (1).
2. Avoid soft drinks and juices containing sugar
For lunch a quick coke or a delicious juice spritzer, there's nothing wrong with that, is there? Unfortunately, there is since soft drinks and juices contain a lot of sugar.
Also, stay away from so-called diet sodas. The artificial sweeteners in them make your body believe that it is getting calories, but does not trigger a feeling of satiety. This increases the risk of a ravenous appetite and can promote weight gain in the long term.
Try to drink mainly water. If pure water is too boring for you, try mixing it up with fresh mint, sour lime, or healthy ginger (2).
3. Drink lots of water:
Simple but true: Water does not contain any calories, but instead burns them. "Even the consumption of 1.5 to 2 liters of drinking water a day can increase energy expenditure by up to 100 calories, even in overweight people," says Dr. Michael Boschmann of Charité University Medicine Berlin (3).
To intensify this effect, it is best to drink cold water. With cold water, your body has to first warm it up to body temperature, and this burns extra calories. Drinking plenty of water not only boosts your metabolism but it also supports digestion and prevents headaches due to dehydration.
But how much water should you drink? The general recommendation is to drink eight eight-ounce glasses of water per day.
Another good trick is to drink additional water about 30 minutes before a meal. This will make you feel fuller and eat less. If you want to lose weight, black coffee without milk or sugar and unsweetened tea is also recommended in addition to water (4).
4. Do endurance and strength sports:
Muscles make up the majority of energy consumption since we burn about 1200 to 1500 calories per day at rest. The greater the proportion of muscle mass in the body, the higher the basal metabolic rate, and the higher the energy consumption.
Studies have shown that even short sessions of strength exercises several times a week can increase the basal metabolic rate by an average of eight percent after only six months. In other words, this means that about 125 more calories are burned per day.
That is why it is important to do weight training in addition to interval and endurance training. Strong muscles not only protect your internal organs and strengthen your immune system, but they are also crucial for a fast metabolism (5).
5. Avoid unhealthy snacks:
Granola and energy bars, dried fruit, and trail mix are often advertised as healthy snacks for in-between meals, but in reality, they are incredibly high in calories. Make sure that your snacks contain enough nutrients. Instead of processed snacks, try vitamin-rich fruit or vegetables, natural yogurt, or nuts.
Avoid eating baked goods that contain a lot of sugar or fat. These will quickly fill you up, but leave you feeling hungry again after a couple of hours.
You can find delicious snacks under 150 calories here!
To summarize…
Calories, or kilocalories, are the outdated unit of measurement for the energy that our body burns every day and that we take in again through food in the form of carbohydrates, fats, and proteins. These nutrients are broken down and utilized in the digestive tract. This releases energy, which we measure in kilojoules (kJ), kilocalories (kcal), or simply calories (cal). One calorie is equal to one kilocalorie and 4.18 kilojoules.
The basal metabolic rate for women is calculated approximately with the formula: 0.9 * bodyweight * 24. For men with the formula: bodyweight * 24. Then it is multiplied by your personal PAL number to give you a rough estimate to your calorie requirements per day.
Especially if you want to lose weight, it can be very helpful to have an idea of your personal basal metabolic rate and calorie consumption and thus develop a better feeling for how many calories can or should be eaten.
In order to increase your daily calorie expenditure, a correct diet is important. Avoid soft drinks and unhealthy snacks, eat protein-rich foods, and drink plenty of water. Strength and endurance sports also help to additionally boost the number of calories you burn.
