High fructose corn syrup is a big contributor. Don't discount all the food colouring and preservatives, which are there aplenty. Fast food....do I have to say any more?
I get a feed once in a while on FB about beach shots in the 70's and there is not a fat person in sight. As someone whom has been fit all their life (but worked at it) I realize that you are what you eat. But the lazy, sedentary lifestyle today, where in the US obesity is the number one cause of preventable death (all factors included) overtaking smoking, which is saying something. 30% of the US population is either morbidly obese or obese. Not just fat or pleasantly plump.
Even worse, the food industry is no different than any other; how to get people to buy the products. Gambling comes to mind on how to market itself. Food has taken notice. High fat, high salt, high sugar makes for a great "hit". And perfectly legal. In fact, it is more expensive to eat healthy than to eat fast food. Not good. And once you are sick with either diabetes, or any other ailment, the medical system steps in with medications to help......generating more revenue and profit. If only the issue was noticed at the start.......correlation or causation. I think the latter.
And with the generation we have today we have ADHD, autoimmune disorders and autism, all at much higher rates than when I was a kid (b. 1972). I went to an elementary school where no one had peanut allergies (they never banned PBJ). Never had anyone with ADHD or autism. I believe it is not vaccines but diet. This is the only variable that goes across all spectrums. To have a bottle of Coke as a kid was a big deal, and I never had coffee until my teens. Today, drinks loaded with sugar and caffeine (and labelled as health product, energy drinks) can be had by anyone, and especially the young. This would have never happened when I was a kid. I had to sneak a bottle of Coke when I could afford it. Caffeine was out of the question. Today, it is a norm for all of us and younger ones especially whom don't need any stimulation. I worked at a sports-fishing resort in my university years and those outside of the PNW commented, routinely, how they found us all "caffeine addicts". That was the 90's.
And yet, in this time, we have ebikes to remove any pretence of cardio fitness or exertion, food delivery services to bring stuff to your door rather than taking a 10 minute walk to get it. I wonder how many actually make a choice to walk to get where they are going rather than use the car for a 2 minute ride when the 20-30 minute walk would do so much good.
You reap what you sow, and as a society we have not planted well, and by design. All for profit. But then something is gotten for cheap on the easy is held in contempt and I see this issue only getting worse over time. Participaction came up in the 70's and may seem corny now but we need it more than ever. Unless the idea is to have fewer healthy people. After all, you have no medical industry unless you have sick people to "cure". And you get them sick by what they eat......