Depends on how you shop. If you buy premade food, you’re right. If you buy ingredients and prepare yourself, you’re less right. It’s a scale.

You can have pasta, or sauce (crushed tomatoes), but not both. No salt, no garlic, no onions, no olive oil. One ingredient.

Literally everything I buy and eat/drink has one ingredient.

Every single vegetable. Every single fruit. Water (I get it from the tap), rice, pasta, noodles. Meat. Eggs. Fish.

The point is that ideally all food processing occurs in your own kitchen. Of course the food you end up eating will be comprised of multiple ingredients; by only buying food ingredients that are in their original unprocessed form, and combining them yourself in constructing a meal, you have full control over the ingredients you are consuming.

Bulllshit.

Steak, chicken breast, cabbage, carrots, mushrooms, turkey thighs, spinach, corn on the cob, some organic peanut butters, flour, salt, zucchini, eggplant, pork chops, tomatoes, potatoes, yams, vinegar, olive oil, bok choi, broccoli, asparagus, beef liver, canned tuna fish (are we really going to split hairs over the salt brine?), ground beef, garlic, onion, shallots, spring onion, iceberg lettuce, watermelon, peaches, bananas, apples, eggs, mahi mahi, chives, cod, romaine, gem lettuce, kale, walnuts, almonds, leek, etc.

Even if you don’t apply common sense to this heuristic and include milk, cheese, bread, good quality bacon, etc., there is a veritable cornucopia of strictly single-ingredient foods available.

But yeah, you’re gonna have to buy ingredients and cook actual meals to be healthy. No way around it, I’m afraid…

Fruits, great. Many vegetables. And steak.

You're not putting anything on the chicken or turkey? You're going to have ground beef by itself? Are you biting into that onion like an apple? And the garlic? Iceberg lettuce by itself sucks. What do you mean "flour", what do you mean "salt"?

Combining the "single" ingredients into a home-cooked meal is perfectly fine.

Keep reading to the end.

I also have a hard time believing this is a genuine source of confusion…

I read to the end. If "cook actual meals" is supposed to imply combining ingredients then you broke the rule of "only eat and drink things that have one ingredient". Otherwise I don't know what you're referring to.

I'm not confused by minimizing processing via home cooking, I'm confused by how your list was supposed to be relevant to the comment you replied to. That comment had a very specific objection.

(And yes, I see that the OP has now replied saying you can combine ingredients at home. But I think the skepticism toward the original phrasing was valid.)

You're playing dumb. We know this.

I'm not playing dumb. At this point I'm accusing them of saying the wrong thing.

"Buy things with one ingredient" is one idea. "Only eat things with one ingredient" is a very different and much more narrow idea.

And don't say it was obvious what they meant. I've seen people claim much wilder things about healthy eating than "don't combine ingredients".

So you don't know how to cook and prepare food? Get a book about it. If you read English, and especially if you are American, you might as well get Joy of Cooking.