True.
It is also true that the elderly have a tendency to revert to their childhood eating habits, so if someone's Scandinavian, by the age of 70 they'll be aching and craving for smoked herring...
...if one's English, he'll be craving for a proper steak&kidney pudding (the one with the batter made strictly with flour, salt and lard) or a chicken&leek pie...
My parents are on the "old" side of 70, and there's a marked change in their eating habits compared to 20 years ago (especially my mother's, she cooks, my Dad simply eats what's on the table)
So, no more healthy salads and steamed fish, now it's stewed sausages and pork chopsand potato salad ...
(my Mom's from Trieste, so it's actually Austrian cooking).
So, don't be surprised if the elderly stuff themselves with foods that, at their age, "don't make sense", because they're simply going back to their childhood memories.
Photojoe, if that old neighbor of yours spends all his time smoking and drinking wine, buying him a gallon of his favorite is like giving him a derringer to play russian roulette (please forgive the pun)
Buy him something he'd like but can't afford, or, quite simply, cook him a tray of lean burgers or whatever he may like.
It could actually be cheaper and win you an even broader smile.