at 55 years old i eat a vegan diet have lost over 50 lbs over last few years. I am lean all over, except my abs. For the last year I have worked intensely at Krav Maga, kickboxing, kettle bells. Problem is that I cannot reduce the fat around my midsection (there has been some reduction, but still flabby). Should I continue with weight loss? Looking for best, healthy approach to firm abs.