To have the looks alone of a runner you’d need to take in the normal range of calories you’d need to take in, this is called your calorie maintenance levels.

It just means what you need to get by each day without particularly changing in weight.

The runner would need maybe a slight increase in calories to account for burned fat so maybe a surplus of let’s say 200 – 400 or so calories depending on bodyfat % and the distance run, also accounting for genetics with the amount of sweat produced, some people sweat more than others.

Runner’s would have around 15 – 20% bodyfat and likely pretty defined and muscular leg muscles such as calves, quads and also strong abs due to running forcing you to maintain good form and have your core which is your support in the middle region of your body such as abs, obliques etc holding your body upright and steady.

Diet itself can vary depending on muscularity, bodyfat, height and genetics like metabolism etc.