“Is this an important factor to take into account”
One of the main misconceptions I face from a lot of people is thinking they have to be consuming 5-6 meals per day minimum to “keep their metabolism up.”
Thermic effect of food or what you would see as “keeping your metabolism up” is dictated by the caloric load or amount of the food consumed (and type) not the consistent intake of it.
One meal of 1200 calories will have the same affect as 3 meals of 400calories with the same macronutrient breakdown. The only real benefit to spacing foods out every 3 hours is the initiation of MPS (muscle protein synthesis) by the way of adequate consistent protein intake.
The take home message;
Consume the number of meals per day that make adherence to calories and macros easiest for you. And …. if possible space out protein intake through the day for a small benefit.