What exactly is fat loss?
We can simplify fat loss to two things:
Energy in - Energy out
What does this mean?
Energy Balance
If your energy input is the same as your energy output you’ll maintain your weight
If your energy input is greater than your energy output you’ll gain.
If your energy output is greater than your energy input you’ll lose
Energy output includes your basal metabolic rate (BMR). Which is essentially how much energy you need to do the least amount of things: breathing, organs regenerating; lying down on your back doing the absolute minimum. For most people that accounts for about 60% of the amount of calories you expend every day.
What is a calorie?
Calorie = a unit of heat. That’s why we say ‘burn’ calories.
Some other useful terms:
N.E.A.T: ‘Non Exercise Active Thermogenesis’: everything outside of structured exercise: walking, cleaning, shopping etc.
EA : Exercise Activity.
TEF: The Thermic Effect of food: around 10% of your daily energy output.
If we want to lose fat we have to increase N.E.A.T and exercise activity (our output) or decrease our input or both. This leads to a tipping of the scales in favour of fat loss. BMR is pretty static, N.E.A.T AND EA is more easily modifiable, TEF is slightly modifiable.
Calories In
Your biggest control is your calories in. So let’s say your maintenance zone is 2000 and you drop 500 calories, you are going to be in a negative energy balance and you’ll lose weight. Increase activity and you tip the scales a little more in the favour of fat loss.
Why Macros Are Important
To tip the scales even further in your favour we can add in a high protein diet, why? Because protein has a higher thermic effect on food (TEF). Protein requires more energy than any other macro to digest so eating a higher protein diet can give you the edge when the goal is fat loss. Fibre also requires more energy to digest and therefore a high protein and high fibre diet is conducive to fat loss. If you do this you’ll also stay fuller longer meaning you’re more likely to be able to adhere to your deficit. This concludes that fat loss can be affected by the macro nutrient composition that you choose.
Why you’re not losing weight in a ‘calorie deficit’
Lots of people say ‘I was eating in a calorie deficit and never lost weight’, well, by definition, if you are not losing body fat you are not in a calorie deficit. Remember that online calorie counters are just an estimation not an actual fact, so if you’re not losing you do one of two things: increase output or decrease input, or both. Your maintenance calories are not a static zone, they move and there are many variables which can affect them such as long term dieting, aggressive dieting, over exercising and hormones, so you will need to experiment to find your maintenance zone. Think about it as a sliding scale.
Maintenance Zone
Your maintenance zone goes down when dieting for a number of reasons:
Your BMR goes down because your lean body mass decreased over the dieting period.
Your TEF goes down because your body becomes more adept at functioning on those lower calories.
Your N.E.A.T decreases because your body is trying to make energy savings due to the lack of input.
Typically Exercise Activity goes down because your body gets more efficient at burning less calories to help keep you from starving.
As these go down the output goes down, energy intake (calories) may not go up, but what this does is push you back to maintenance. Your body is always trying to get you back to homeostasis.
When this happens you either increase exercise activity or decrease calories to keep losing weight and this brings us back in a circle to the simple equation:
Energy in vs Energy out.