(3/5) In vs. Out

In Vs. Out


Aim of Article: to explain the importance of daily energy requirements in relation to training goals


The amount of energy (calories) you need per day depends on four factors:

  1. Basal Metabolic Rate (BMR) – sum of all the calories your body burns while at rest and keeping you alive, from hair growth, running your organs, thinking etc. Basically all the calories you would burn if you did absolutely nothing all day.
  2. Thermic Effect of Activity (TEA) – calories required for exercise
  3. Thermic Effect of Food (TEF) – calories required to digest and absorb food you eat. Some foods require more energy to digest than other.
  4. Non-Exercise Activity Thermogenesis (NEAT) – calories required to fuel all non-exercise specific exercise. Scratching an itch, sneezing, fidgeting witha pen, sitting restlessly etc. It surprising how large this factor can be.


The sum of all these factors is known as the Total Daily Energy Expenditure (TDEE). This number varies person to person for many reasons, from size, genetics, diet, exercise levels, fidgety-ness etc.

Adapting dietary intake to be less-than (<), equal-to (=) or greater-than (>) TDEE forms the cornerstone and starting point of any successful diet. That’s not the say it is the only factor, but it cannot be stressed enough how vital the following three simple statements are to any transformation.

  1. Energy/calories consumed > energy/calories burned (TDEE) = increased fat or muscle levels
  2. Energy/calories consumed < energy/calories burned (TDEE) = decreased fat or muscle levels
  3. Energy/calories consumed = energy/calories burned (TDEE) = maintained fat or muscle levels


Obviously the sources of these calories also plays a big role in your strategy, from helping you perform better in the gym and life, build more muscle mass, prevent muscle wastage, avoid nutrient deficiencies etc.

We can increase TDEE though increasing muscle mass and activity levels. But it can be also reduced through inactivity, reduced muscle mass or starvation.