That's not true, since you want muscle mass even for health reasons. The requirement for increasing muscle mass when doing weight training is at least 1.6 g/kg

That's not true, since you want muscle mass even for health reasons. The requirement for increasing muscle mass when doing weight training is at least 1.6 g/kg of bodyweight or thereabouts, which is a huge amount of protein for example, I'm 93kg, which sets my dietary protein to 150g or thereabouts I need 2700 calories a day for maintenance that means even if I do nothing but drink full fat milk, I will have gained only 135g of protein from my calories, which isn't enough to optimize for muscle recovery after training this is why I slip a few grams of protein powder into my morning coffee, avoid eating foods high in carbs and fats, just to approach that number (I may not hit it exactly every day)