F/33/5’2” [130>125=5lbs] (6 months) Is this postpartum belly a diet problem or genetics?

I’ve been training for a backpacking trip that is going to be incredibly grueling in a couple weeks. I’ve been training with my 40 pound pack while living below sea level by hitting the stairmaster and going up any rock scramble or creek bed I can in order to get in my miles. I’m incredibly proud of the cardiovascular and skeletal strength I have built, the strongest I’ve ever been. Alas, four years after having my child I’m afraid I will never wear a low rise bikini again. Yes, I love dessert, probably too much. Is this layer of belly fat based on diet? Or will it have to be fixed with a tummy tuck?

Skin color is different because I had a spray tan.