> And so the dilemma is, do I say something to him? He looks like he is in awful health and high probability with an awful diet (based on profiling him). But I don’t interact with him or have any type of relationship and saying something would be incredibly awkward. Surely he knows I tell myself.

It's an interesting question—if you have knowledge about human health based on a person's appearance, do you share that information? I think a physician may not do that for a stranger, but I imagine you aren't a physician.