Donuts and dbol don't prevent anyone from losing weight. It's not the food choices so much as it is the quantity of food choices and how they fit within one's diet. I can get to 10% BF eating ice cream and brownies regularly, my buddy earned his pro card eating brownies, ice cream, mcdonalds, donuts etc up to 4-5wks out from his show. Now I won't be able to get to 10% BF if I eat gallons of ice cream daily but that doesn't mean I can't have a few scoops every few days if I want to.
What I recommend for OP is to get into a calorie deficit. Anywhere from a 10-20% or larger deficit depending how fast he wants to achieve fat loss. Maintain a sufficient protein intake of 1-1.25g/lb. Meet his minimum dietary fat requirements. If he doesn't want to go keto then add in as many carbs as he wants so long as he maintains the calorie deficit. After 2 wks do a refeed. As he gets leaner he might need more frequent refeeds. Cardio isn't needed for fat loss but if he wants to do it (he says he likes swimming) then do some light to moderate cardio/swimming.
.
