start with eating salad from mcdonald instead of fried chips, then eat only burgers with good ingredients. with time start to cut fried things like nuggets and sweets. then if you want mc or other shit you should go take it by walking. once you’ve done all this shit in 3/4 months you can start with a normal diet, cutting trash food and working out in a gym… but don’t take that too rapidly because otherwise you would come back to mcdonald’s in no time