From training in the gym, talking and engaging in bedroom athletics it all requires calories. Even eating food requires energy as we need them to digest and absorb nutrients.
TEF or Thermic effect of food is the amount of kcals needed to process what we eat and protein burns more energy on consumption than fat and carbohydrates .
Studies by the likes of J.Antonio /S. Phillips suggest we eat anything from 1.6-2.4g per kg of body weight in protein ( depending on the individual ) to not only support recovery and muscle sustainability, but to aid body composition too.
Additionally, excess protein intake ( 2.4 g/kg upwards ) has’nt been proven to increase any fat gain, nor has it shown to be any different to lower intakes.
A lb of muscle roughly holds 600 kcals of energy, comprises 125 g of protein, some water and a little glycogen.
If we take all this information into account when losing weight and trying to sustain muscle, low calorie and low protein diets will consequently result in muscle loss.
Balancing dietary nutrients but prioritizing protein leads to a long term fad free, healthy, effective eating regime.