Sugar, extracts, refined flour, that sort of thing.
Just take Mashed Potatoes. Should be simple - just potatoes. Ingredients of Betty Crocker Potato Buds "Potatoes, Mono And Diglycerides (To Improve Texture), Freshness Protected By Sodium Acid Pyrophosphate, Sodium Bisulfite And Citric Acid. Dried."
Another example, Edy's Slow Churned Light French Silk Ice cream has "Non-Fat Milk, Sugar, Cream, Chocolaty Chips (Sugar, Coconut Oil, Cocoa Processed With Alkali [Dutched Cocoa], Fractionated Palm Kernel Oil, Cocoa, Soy Lecithin, Salt, Natural Flavor), Corn Syrup, Cocoa Processed With Alkali (Dutched Cocoa), Whey Protein, Molasses, Buttermilk Powder, Soy Protein, Acacia Gum, Nonfat Dry Milk, Guar Gum, Carrageenan, Carob Bean Gum, Natural Flavor, Salt, Natural Flavors (Including Malt Extract), Xantham Gum, Caramel Color." Who knows what all those are?
Where possible I make my own food from scratch. (Within reason - I don't milk my own cows, or spend hours making custom bread or pasta)
I'm not an off-the-reservation eat everything raw person, but I am skeptical that most managers would make food less addictive to make it healthier. There are exceptions, but this is one of the negative aspects of a market economy.