Sure, buying Just Salad is more expensive than buying McDonald’s, but that’s not the only options.
The bigger problem IMO: we put way more sugar, sweeteners, and addictive substances in food and have big portions where people feel obligated to finish. It’s very easy to eat 100g of sugar every day and hardly notice. Combine that with most American activities involving food and alcohol.
We have a culture that encourages eating and food that responds by being more eatable
Put another way, the bag of chips at the American grocery is _designed from concept to factory_ to be unable to support living beings. Microorganisms would die from dehydration trying to eat the chips. But due to a bug in human psychology, when we eat them we just feel more hungry. There only regulating feeling we get is guilt.
This is a weird leap. Yes, there is some degree of modern engineering in packaged food to prevent spoilage but "unable to support living beings" is the wrong conclusion. You're implying the food lacks nutritive value, which is not true.
In other countries that shops more frequently there is less need for that, and there these products has much fewer additives.
And portion sizes! There a several factors that lead to such large portions. Americans expect (and now desire, thanks to the ever expanding gut lines) to be stuffed from an ordered meal so producers spend the extra $1 on food costs to ensure larger portions and fewer complaints. We'd complain is the the $9 burger was made into 1/3 sized $3 burgers. Additionally the fixed costs of running a food joint require to low cost and high margin items (like fountain soda) to survive.
Watch what other people eat in their day. How many of their calories came from meals created with only the above ingredients? 25%?
At least in the US where the problem is much worse than in the EU, I would say the major driving factor is the lack of cheap healthy foods.
We're starting to get more healthy options in the US but the problem I see again and again is that food is always painted as "trendy" and therefore commands a higher price. I can go into McDonalds and buy fries and a cheeseburger for around ~$5. But if I try to get a healthier option from another place I'm looking at $10-15 for just about anything.
Every time I travel to Europe or Latin America I'm always shocked at how easy it is to find cheap healthy food. I can pop down to a local fast food place and for around $5 get a piece of chicken, beans and rice. This by no means fancy but it's solid healthy food.