This is a pretty big leap, what is even "true meaning and purpose"? The culprit is that this food is literally everywhere and billions of dollars are poured into research everywhere to design systems that entice humans to take the convenient way out. If I was to go along with your hypothesis, I would alter it to say that poor nutrition is what contributes to a person's lack of "true meaning and purpose".
I agree that society has been designed to make things more and more convenient in the name of progress and that we haven't made the nutritious food convenient yet. Stated another way, poor nutrition is the default choice in most of the western world.
Still, I think its possible to make the idea of "purpose" more concrete. You could define "true meaning and purpose" to be goals that are greater than oneself that require one's full potential in mind and body and sacrifice of immediate pleasures for long-term gain. The widespread nature of obesity indicates that many people don't consider a healthy body as necessary for their goals and hence don't sacrifice immediate food gratification for those goals. Hence most people don't have goals that require their full body potential.
> what is even "[lacking] true meaning and purpose"?
Perhaps the alienation of workers from the fruits of their labor? It's underrated how depressing it is to not get to eat the sausage you broke your back making.
When we talk about things, we sometimes use their relationship to other things to define them rather than talking about them directly. I'm not sure how my answer is irrelevant and deserving of your snark.
