This question is about Running
Runners wanting to lose weight should eat a combination of complex carbohydrates, lean protein, and healthy fats from a variety of whole or minimally processed foods like fruit, vegetables, fatty fish, eggs, poultry, tofu, beans/legumes, and whole grains. These foods support both weight loss and athletic performance.
Modest weight loss achieved through exercise most likely won’t affect a runner’s overall performance so long as there is adequate intake of calories (particularly from carbs and protein), and pre- and post-run nutrition are prioritized.
Low-carb diets are not great for running but a modest reduction in carbohydrate (40-45% of daily calories) may help runners lose weight without sabotaging performance.
To help preserve lean muscle mass, runners trying to lose weight should consume roughly 1.8-2.7 g/kg/protein/day, divided into 4-6 meals or snacks [ 1
Furthermore, having a small meal or snack that provides 1 g/kg of carbohydrate and 0.5 g/kg of protein within 30-60 minutes of a run will promote muscle synthesis, which is important for runners trying to achieve weight loss while maintaining or increasing lean mass [ 1
Kreider, R. B., Almada, A. L., Antonio, J., Broeder, C., Earnest, C., Greenwood, M., Incledon, T., Kalman, D. S., Kleiner, S. M., Leutholtz, B., Lowery, L. M., Mendel, R., Stout, J. R., Willoughby, D. S., & Ziegenfuss, T. N. (2004). ISSN Exercise & Sport Nutrition Review: Research & Recommendations. Journal of the International Society of Sports Nutrition, 1(1). https://doi.org/10.1186/1550-2783-1-1-1