This reminds me of a task I do in (ESL - English as a Foreign Language) class when we’re first talking about food vocabulary (I imagine this would also work with young English speakers). If I know they’ll be able to come up with a decent list (upper-elementary+ learners) I’ll draw two columns on the board, one headed ‘Good Foods’ and the other ‘Bad Foods’.
The ‘Bad’ will have the usual suspects; burgers, pizza, soda, chocolate, KFC, sugar…
The ‘Good’ will have vegetables, oranges, bananas, potatoes, rice, etc.
I know, I know that isn’t strictly true, but bear with me.
Then I’ll ask them "Okay, now how do you put ALL of the ‘Good’ foods on the ‘Bad’ side and ALL of the ‘Bad’ foods on the good side? This will regularly be met with blank or quizzical stares, but rarely an answer. Then I write, across both columns, ‘Amount’ or ‘Quantity’ and tell them to look up the word if they don’t know it. It takes a while but I think most understand the concept of moderation by the end of that class (any struggling usually will understand if I tell them to go out and eat 1,000 apples).
I’ll also, if time and maturity of the students permit, show Supersize Me with English and/or their L1 (First Language) subtitles, as needed.
Personally, I don’t like McDonald’s or other fast food producers’ employment practices, abuse of animal husbandry, marketing gimmicks, or general negligence of their customers’ health or well-being. I’ll be open with my students and say ‘I don’t like/trust McDonald’s et al and only eat fast food once or twice a month’. I think I present a fairly strong case although I don’t do much more than I’ve said - i.e. I don’t think I preach to them, but the countries I teach / have taught in generally have much less exposure to modern fast food, so I considering it giving them a friendly ‘Heads Up’.
As to the OP my (biased) answer is that you know, if you make a burger at home, what’s going into it. If you’ve gone to the butcher’s or meat counter and asked for the beef cubes to be ground up, then made the burgers yourself from the freshest ingredients you can find, it will (almost) always be healthier and will ALWAYS be tastier than some processed, frozen, lump of ‘cow parts’ mechanically recovered/reclaimed, transported and cooked by someone on minimum wage. YMMV.