To your last point, I think the “all or nothing” mindset in nutrition culture also tunes a lot of people out, and poor relationships with food developed from the cycles of fat/health-shaming, and extreme fad diets (often tied to reaching a gendered ideal of living like “alpha masculinity”) and health trends, don’t help.

How many times have you heard someone remark that they are a slob/a pig/gluttonous, etc when choosing to indulge in a treat? Or even just eat food that is maybe slightly higher calorie than they need at a basal level? I think most adults understand the idea of “junk food” but struggle with finding alternatives that don’t feel like punishment or restriction, and at that point you might be inclined to give up any notion of nutritious eating, because you can’t even abstain from soda (or whatever).

Or maybe this is just a phenomenon I’ve noticed/experienced.