We have all heard that fat loss is simply addition and subtraction. What this means is that you +/- from your daily maintenance Calories (TDEE). I am going to show you how to use some simple equations to get a rough ESTIMATE of your STARTING maintenance calories and how to adjust that to help towards your goal.
Let’s go over a few terms that you will be seeing in this guide.
- Total Daily Energy Expenditure (TDEE): Your maintenance Calories for the day. There are several factors that affect your TDEE.
- Basal Metabolic Rate (BMR): This is the amount of calories your body would require to survive if you was in a coma. This will be roughly 70% of the total calories in a given day. Our bodies require a lot of energy just to function and keep us alive. This covers such things as breathing, regulating body temperature, production of hormones and brain activity.
- Resting Metabolic Rate (RMR): This is your Calories if you laid in bed all day and binged on Netflix. This is about 10% higher than your BMR.
- Thermic Effect of Feeding (TEF): Our bodies need energy for digestion, absorption and creating the energy that our bodies need. This is around 10% of the total kcal used per day.
- Non Exercise Activity Thermogenesis (NEAT): This is the normal things we do every day such as typing on a computer, talking, walking around our house & posting on Facebook. This makes up the smallest of all the categories but is still important.
- Exercise Activity: This is the elective exercise that we do to keep our bodies healthy. In sedentary people this can make up 10-15% of their total exercise. In highly active people it can come out to be more than 30% of their TDEE.
TDEE = RMR + Physical activity + TEF
1) Calculate your RMR
The first thing you need to do is calculate your RMR. This will give you an estimation of your bodies basics needs. There are several formulas that scientists have come up with. For simplistic reasons we shall use one of the most common ones.
The Mifflin-St Jeor Equation
Men: (10 x weight in kg) + (6.25 x height in cm) – (4.92 x age) + 5
Women: (10 x weight in kg) + (6.25 x height in cm) – (4.92 x age) – 161
Example: Beth is a 34 year old woman who is 5’9 and 168 lbs. We want to calculate her RMR
(10 x (154/2.2)) + (6.25 x (64/0.3937)) – (4.92 x age) – 161 = 1531 kcal
2) How to Estimate Your Total Daily Energy Expenditure (TDEE)
Now that you have your RMR, the next step is applying the other energy factors above to get your TDEE.
- Sedentary (By sedentary I mean doing nothing all day – sleeping and watching TV)
BMR x 1.2
- Lightly Active (Having a non-physical job (desk, computer, etc.) but performing some sort of physical activity during the day (e.g. above average walking) but no hard training.)
BMR x 1.3-1.4
- Moderately Active (Having a non-physical job, performing some sort of physical activity during the day, and including a daily workout session in your routine. This is where most of you are at.)
- Very Active (Having a physical job + hard exercise/sports 6-7 days per week).
BMR x 1.7-1.8
- Extremely Active (very hard daily exercise/sports and physical job or 2/day training).
BMR x 1.9-2.0
Example: We will use Beth again and find her TDEE. After speaking with her I determine that she is moderately active. This will give us the number of Calories she will need to maintain her weight per day.
TDEE: 1531 x 1.6 = 2450 kcal per day
3) Adjust for Weight Loss/Gain
There is approx 3500 kcal in 1 lb of bodyweight. By taking 500 kcal out a day, over 7 days you will reduce 3500 kcal a week. Don’t forget that results are not linear and do not take into account for the bodies adaption to increased or reduced caloric intake over time. A good rate of fat loss is 0.5-2.0 lbs/week
- If your goal is to cut:
TDEE = – 500 a day
- If your goal is to bulk:
TDEE = + 500 a day
Example: Beth has written down one that of her goals is to lose bodyfat. We will take her TDEE and reduce the Calories.
2450 kcal – 500 = 1950 kcal per day