Hi from North Wales

Hi all,
I decided several weeks ago that I needed to lose weight and regain some fitness after several years of letting myself go. I have started to eat more healthily and ease myself into some regular exercise. I'm six feet tall and used to have a fairly good physique, with broad shoulders and a narrow waist, but now I'm 48" chest and 38" waist and I reckon I need to lose about two stones. I have been looking at some of these programmes where you are supposed to be able to burn fat fairly quickly, but they all seem to be aimed more at body sculpture than losing weight and being generally fitter. As a man who celebrated(?) his 56th birthday last week, I'm not sure that trying to achieve pumped biceps and six packs is really appropriate for me. I want to lose the flab, increase my fitness, firm up my muscle tone and have a reasonably flat stomach - to achieve that goal, if I'm eating sensibly, do I really need to worry about BCAA capsules, protein shakes etc. in order to avoid losing muscle rather than fat when I'm exercising with a combination of cardio, HIIT and moderate weight training ? I'd be grateful for some impartial advice from those more experienced in this field.
Thanks very much