It depends on age (and BMR in general) and type of athletics. When I'm in a marathon training routine (typically a 16-18 week cycle, ramping up to 55-70 miles per week), I'm burning an extra 1000-2000C/day. Considering I'm already an ectomorph, and tall (6'3" 185lbs), I have to eat a lot just to maintain. I don't always make good choices (last night I snacked on pretzels and toffee), but somehow my body self-regulates ingestion and I have never gained weight. I know it sounds hokey, but I am convinced my body does an excellent job telling me whether I need protein or carbs/sugar. Not so much fat, so I eat cheese & similar with intent, but you get the idea. My problem is finding healthy calorie heavy snacks. Avoiding empty sugars & simple carbs while snacking is a challenge.
6'4" 200 lbs here, marathon training and vegan... I eat very little refined sugars any more but I do consume a large amount of my calorie needs in grains and rices. Interestingly I was 230 or so in weight right up until I started cutting out the sugars, oreos are vegan, ice cream can be vegan, etc.
