Just having muscle burns calories. The problem with people who only say "eat less calories than you burn" and stop there, is that there is you cannot tell someone how many calories they are burning during what activities and what time of day. There is no standard calculation for an individual, just averages and estimates for the whole population. Also over what period of time is it calculated? How much caloric store is already in the person's body? What is their metabolism like? This is all before getting into the quality of nutrients consumed that you all are talking about.

It's generally a good rule of thumb and starting point though.

Just having muscle burns calories. The problem with people who only say "eat less calories than you burn" and stop there, is that there is you cannot tell someone how many calories they are burning during what activities and what time of day. There is no standard calculation, just averages and estimates. Also over what period of time is it calculated? How much caloric store is already in the person's body? What is their metabolism like? This is all before getting into the quality of nutrients consumed that you all are talking about.

It's generally a good rule of thumb and starting point though.