How to calculate your total daily energy needs
If you want to lose weight effectively and quickly, it’s important to estimate your total daily energy needs. This post will describe what I mean by TDEN or total daily energy needs and how do we calculate it.
Total daily energy needs explained
Your organism needs a certain amount of calories/energy every day to stay in energy balance. This is how you maintain your weight. Thus, if you know how many calories you need to stay in balance, then you can reduce the number of calories/energy that you are taking in, to lose weight. Generally speaking, the energy intake for weight loss should be reduced from 250 to no more than 800 kcal/day of present intake. Moreover, a weight loss plan should never provide less than 1200 kcal/day. This is just general guidance. A nutritional programme for a successful weight loss needs to be entirely personalised to an individual.
Now we know that we need a certain amount of calories to stay in energy balance. Next, we will take a look at how do we calculate this number and how to proceed from there.
To estimate our total daily energy needs, we need to know two things:
- Our BMR or basal metabolic rate.
- Energy cost of our daily activities.
BMR or basal metabolic rate
BMR or basal metabolic rate is our energy expenditure at rest. In other words, it’s the energy expended just to maintain our body’s resting functions. These functions include respiration, circulation, maintaining body temperature, our nervous system activities, etc.
The fact is that the majority of our energy output each day is a result of our BMR. This translates to 60% to 75% of our energy output fueling the basic activities of staying alive, aside from any physical activity.
Our BMR decreases with age. This is due to some of our hormonal changes and irregular physical activity, which causes the loss of lean body mass.
To calculate/estimate your BMR, multiply your body weight in kg by 1 kcal per kilogram body weight per hour (for men). If you are a woman, multiply your body weight in kg by 0.9 kcal/kg body weight/hour.
My weight: 85 kg. 1 kcal/kg body weight/hour x 85 kg= 85 kcal/hour. To calculate my BMR for the whole day (24 hours), 85 kcal/hour x 24 hours/day= 2040 kcal/day.
So, 2040 kcal, my body is expending just to keep me alive, at rest. Our bodies are the true work of nature.
Energy cost of our daily physical activities
The energy cost of physical activity represents about 15% to 35% of our total energy output each day. This is the energy we expend due to any movement or work. It can include lower-intensity activities such as sitting, standing, walking, and higher-intensity activities such as running, skiing, and bicycling.
We can never accurately calculate the exact energy cost of our daily activities; however, we can estimate closely.
We will use the table below to estimate our values.
In our calculation, we will use the low and high percentage of BMR in the table above.
Let me show you how this part works in my example. So, we calculated my BMR to be 2040 kcal/day. To calculate the energy cost of my daily physical activities, I need to select my current activity level from the table. I am heavily active, thus, my low value is 90 %, and my high value is 120 %. Now we can proceed with the calculation:
2040 kcal/day x 0.9 (90 %) = 1836 kcal/day.
2040 kcal/day x 1.20 (120 %) = 2448 kcal/day.
Out of my example, we can conclude that I expend about 1836 to 2448 kcal/day doing my daily physical activities.
FINAL STEP: Calculate total daily energy output by adding together BMR and the energy needed to perform daily activities
To finish our daily energy needs calculation we need to add our BMR value to our energy cost of our daily activities. Let’s see how we do that in my example.
2040 kcal/day + 1836 kcal/day = 3876 kcal/day.
2040 kcal/day + 2448 kcal/day = 4488 kcal/day.
Assuming that I am trying to maintain my current weight, I require between 3876 and 4488 kcal/day to stay in energy balance.
To make it easier for all of our readers, we created a free tool called The total daily energy needs calculator. You can download it for free at https://trainchampion.com/free-tools.
This exercise of calculating the total energy needs will help you determine how many calories you need to cut back to lose weight. If my goal is to lose weight, I would gradually reduce my calories below my daily energy needs threshold. This segment needs to be entirely personalised to you.
Until next Tuesday,
Damir Pervan, Founder and CEO of TrainChampion