Food intake as a runner

How can I best fuel my body to run 25-30 miles per week but find the right balance between overeating and undereating? I’ve increased my mileage about 20% since last year and put on both muscle and fat but want to be leaner and keep my energy up. I monitor my weight and body fat percentage using the same scale and I’ve gone from 126 lb (26% body fat) at 5’2″ – stable weight since college, even after 2 kids – to 133 lb (25% body fat) in a year and I can’t seem to budge that 133 lb back down.