Not everyone has time, or money to eat healthily. Granted a lot of people make the choice to eat shitty, but to some thats all they can afford. Read Nickel and Dimed
health is expensive.
That is a myth and a fallacy, imho.
Agreed...
"Expensive" is relative. Everything you pay for (in time or in money) is an
investment. What makes something "expensive" or not depends entirely on the
return on investment.
Example:
I buy a used car for $1000, because that is all I (think I) can afford right now. However the car has some maintenance issues so I need to spend about $100 on repairs every month for it. By the time a year has passed, the car has cost me $2200. And now that it's older and has more wear and tear, I will have a hard time selling it and getting much of that money back.
Perhaps I could have re-examined my priorities and budget, and skimped elsewhere in my budget (cutting out the daily Starbuck's latte, for example), and put that money towards a car with a higher cost. If I had purchased a better-quality used car for $2200, I maybe could have gotten a car with no maintenance issues, that would have lasted me a long time and had better resale value.
Which was the more "expensive" car?

To me, health and education are the two investments that are ALWAYS worth it. Education is something that, once you have it, it can never be taken away. It's the only guaranteed permanent investment there is. It will never depreciate. Whether or not you get a return on it (in terms of monetary value) kind of depends on market forces, etc. But once you have knowledge it is with you forever; once you have a degree or certification or something like that, it can't ever be taken away from you (sure, maybe some certifications expire, but it's not like the knowledge evaporates... you maybe just have to jump through a few hoops to renew, but you always have the knowledge with you).
Health is similar, but kind of in the reverse. It's one of those investments you start out with a full account balance of, and then depending on how you spend it, it either stays a high balance or it dwindles. Once your health starts to deteriorate, it can be very very hard to get it back again. If you are healthy and able, you can participate fully in life. You can be alive as opposed to just living. For me personally, I would rather die than spend life in and out of hospitals, or wheezing after going up a flight of stairs, or not being able to play with my dog or dance or hike the Andes, etc...
When our cars break down, it's a relatively simple matter to replace the parts and get back on the road. When our bodies break down, it's a much different story. You only get one body.
In my view, spending the extra time and/or money on health is always a worthwhile investment, because of its return on quality of life. To say nothing of the cost savings on medical care. It costs WAY more to have a heart bypass, which is only one day of your life, than it does to eat healthy across a lifetime.
</soapbox>

Back on topic...
I don't care for McDonald's at all, or any fast food place, really. I eat fast food maybe once a year; usually on road trips when there is truly no other option (i.e. my cooler packed with healthy snacks is empty; all other restaurants are closed, I'm in the middle of Nebraska at 10:00 pm). By that point I am eating to put calories into my body for fuel, nothing more. I try to make the healthiest choices I can given my day... a salad with chicken or something if I can, but in general, I just don't eat fast food. It feels icky in my body usually.