Starting a Fat Loss Program Part 2 - Daily Energy Needs - Metabolism Basics

In our previous article on the bodies energy balance principle, we learned what causes the body to gain or lose fat. In today’s article we will learn the first foundation of weight-loss which is understanding your daily energy needs. This part may seem tedious as I am laying it out here manually, but there are many apps and wearable devices that make this portion a breeze once you understand the underlying principles.

Let’s start by reviewing the formula we learned in Part 1 - Energy Balance Principles. The formula below shows how the body stores excess energy as fat or burns excess fat for energy.

Energy Intake( Food ) - Energy Expenditure( BMR* + Activity + Exercise ) = Weight Gained or Lost


Calories in - Calories Out = Calories gained or lost as body fat

Today we will focus on the filling in second half of the formula.

Energy Expenditure = ( BMR* + Activity + Exercise )

To complete this portion of the formula we need to know our Basal Metabolic Rate(BMR) and how to calculate activity/energy expenditure.

Basal Metabolic Rate or BMR is the scientific term for how much energy your body uses each day just to keep you alive and maintain your current weight. It takes into account your age and gender, as well as your size(height and weight). It will also try to calculate an activity level for you, but I recommend using the BMR associated without including lifestyle activity and then we can add in activity based calories separately.

Click the link here and enter your information to find out your BMR as it is today. Remember you will need to recalculate your BMR as you age and as you lose/gain weight.

For example my BMR as a 39 year old, male at 5’9 220lbs is 2073 Calories.

Energy Expenditure = ( 2073 + Activity + Exercise )

We can see the formula coming together but now we need to add in daily activities. This is where wearing a smart device like a fitbit can help you in your weight loss, it will keep track of your steps for the day and can even estimate calories burned during exercise. I will touch more on technology in weight-loss in future articles. For now let’s assume you don’t have a fitbit or other wearable device, you can simply start by using your phone as a pedometer as most come with this basic app these days.

To estimate calories burned based on steps view the chart on this page

To estimate calories burned during exercise use this form.

Today I have taken 7188 steps and burned about 382 calories in the process I also did a weightlifting exercise routine and burned 650 additional calories doing that.

Energy Expenditure = (2073 + 382 + 650) = 3,105 kcals

So now that my formula is complete I can see that my energy expenditure for today is 3,105 Calories. Knowing this number is what will allow me to consistently create a calorie deficit. If I did not take the time to calculate this number, anything I do in trying to lose weight is just a stab in the dark. This number will vary from day to day but you only need to calculate a few types of days(Work-Out Days, Lazy Sundays, Cardio Days) to learn what your daily number should be each day or you can make it really easy on yourself and use an app like fitbit or myfitnesspal which tracks your BMR, daily activities and allows you to journal food against the total so you can be sure to hit your nutrition/fat-loss goals.

So, now that we understand our daily energy needs we can move on to the most important part of any fat-loss program Calorie deficits. Click here to be linked to the next article now.


about the author


is a certified member of the Canadian Association of Fitness Professionals and C.E.O in the software development sector. With a passion for personal fitness and helping others achieve their best health and performance Aaron coaches nutrition and exercise programs at Elite Personal Training in London, On.