If you are in line at the market, it's fairly natural to notice what's in the cart in front of you while you are just standing there waiting to be checked out. I always do, and it's usually not surprising.
My brother's cardiologist made an apropos remark about the packaged pre cooked meals in supermarkets, observing that while it's a good thing to learn to read labels, it's even more to the point to buy the foods which don't carry labels.
That is what I try to do. I also cook with natural fats. I make home made spaetzle with pork chops. That is not exactly diet food, but I use portion control and serve with a veggie and salad. Glad to see that I am not the only "busy body". I have even been so bold as to notice a piece of "naturally" wrapped fruit in someone's cart and asked the person with it how to pick a good one. Gasp, the horror!
I'm not a cardiologist, nor do I need one, but the remark makes a great deal of sense.
More than 50% of my grocery bill is from foods with no ingredient labels - even less from mid summer to early fall because so much is coming out of my own garden.