Also, breakfast items are typically the "healthiest" fast food items. An Egg McMuffin for example has a fresh egg, piece of ham and an English muffin. Hardly a disaster meal diet wise.
The quarter pounder is loaded with sugar too unfortunately. The sweet bread is one of the worst things about it. The salad dressing will be too. It's not healthy and doesn't even taste good. But it's addictive.
It has 10g of sugar, which isn't good but no where near a medium coke. Though not a healthy meal because of high sodium, but with some added fibers isn't very bad.
It's a bit more subtle than that. The sugar is there to make it palatable and addictive. The real problem is it's hyper-processed and ridiculously easy to digest. It'll spike your blood sugar levels then have you wanting more an hour later. There's no point looking at a single food in isolation, you have to look at the entire lifestyle and the kind of lifestyle that includes McDonald's is not a generally a healthy one.
Then again Buffett apparently did it for 6 decades. But he also only had to drive a few minutes to work and probably had a mostly stress free life. You can eat all the healthy veg you want but if your day is punctuated by a dreadful commute and generally filled with stress, that's what will get you.
The hamburger buns I buy at the grocery store taste like cake to me. There's only one brand of bread in the store that doesn't add sugar, and they only stock a couple loaves at a time (and it's the one I buy).
The sugar in the McBurger is nothing like the amount in a coke or a shake.
And no, McBurgers are not addictive. I don't want more than one or two a month.