No advice but I empathize. I can CICO myself into oblivion without difficulty--face and limbs become skeletal but the torso never budges. I was officially obese at age 8 so who knows if that had an effect on development.
Lots of: urban hiking, cycling, sprinting
Lots of: fresh meat, seafood, eggs, organs, tubers, starch fruits, vegetables, meat fat, dairy fat, oil fruits
Some: cured meat, dairy protein, sweet fruits, rice, pulses, tree nuts, oil seeds
Minimal: soy, refined proteins, sugar, liquid carbohydrate, grains, refined oils, peanuts