You must understand this before starting any “diet”.
Dieting can have a significant impact on energy balance.
As we already know, the amount of calories that you burn in a day could be different each day. To lose weight, you need to consume less calories than your body is burning. However, dieting can actually lead to a decrease in your daily energy needs. Here’s how:
Dieting can impact your BMR:
When you diet, you’ll often be losing some muscle mass while losing fat mass. Muscle mass is your metabolically active tissue. The more muscle mass you lose, the lower your BMR.
Dieting can impact NEAT
If you are in a large deficit, chances are, you are going to be feeling pretty sluggish. When we are feeling sluggish, our incidental movement decreases. This means that across the day you may be eating less, but you are also likely moving less and therefore, burning less calories.
Dieting can impact calories burnt during exercise/training