Do you ever catch yourself talking about indulging in rich food in terms of "being bad" or "naughty"? Have you ever "cheated" on a diet? Why do we use moralistic language to talk about "good" and "bad" food?
There's a whole diet culture as a tool of the patriarchy line of critique that is well worth exploring. But I think there's also a simpler, fundamental human reason why we are inclined to assign moral value to food choices. It's that we have a deeply rooted instinct for community and culture around what to eat, how to cook, where to forage and how to harvest, and everything else related to food.
Our family tree of primates have been living in mixed social groups for perhaps 50 million years. Early humans started cooking a million or two years ago based on use of fire. There's direct evidence of fish being cooked 780,000 years ago, which predates anatomically modern humans by several hundred thousand years. The earliest known domestication of edible grasses occurred 23,000 years ago, and we have been innovating food production ever since.
This is why diet culture is so sticky: because it hijacks cultural tooling that is fundamental to our evolution. We've been sharing food with our communities, and making rules and recommendations and taboos and virtues about food, for as long as we've been human.
The way humans enforce rules is through moral weight. You are a good member of society when you follow the rules. You are bad and dangerous when you break rules. This moralizing was a helpful tool for early human cultures to transmit and enforce information, and to enforce social cohesion and increase the group's chances of survival. But it can also be at odds with other useful human instincts such as those for innovation and learning.
Obviously moral rule-making isn't limited to food. Humans make "thou shalts" and "thou shalt nots" about all sorts of things.
And on the flip side, some choices around food are moral or ethical choices, such as when we make choices based on environmental impact or humane treatment of animals. (For instance, here at Sultry Health we're big on regenerative agriculture and pastured animal products along with wildland conservation.)
But eating brownies is not a moral choice. Nachos are not naughty. There's no sin in cake and ice cream. Those might be food choices that are inconsistent with your other health goals, but eating them anyway doesn't make you a cheater. It just means that you are going to live with the consequences of eating those foods, based on how your body is able to process them.
You should eat food that makes you feel better, not worse -- not because it's morally correct but because then you get to enjoy the consequences rather than regret them. And while too many brownies makes me feel worse, an occasional brownie makes me feel better. Understanding your own body and its responses is key.