The main problem is that he used it as an excuse to over eat, and also stopped exercising. And then declared the changes in his health were on McDonalds. Some chick did a “counter” to it, she also ate McD every meal, but kept her calorie count healthy, kept up her exercise routine, and lost weight.
If you go to any restaurant and say “yes” to every “add on” you’re gonna gain weight. That’s just the math of excess. It’s not the restaurant.
I think the main point was the demonstrate how out of whack serving sizes have gotten. But from how you described it, it does look like what he did was way out of line.