[benj111]

"I think it’s a status thing"

I'd say its a politeness/not appearing greedy thing, certainly from a food in the centre of the table point of view. Drives me mad when at the end on a dinner party you have one potato, one carrot stick, one chunk of bread.

This is from a UK point of view, I understand there are different motivations elsewhere.

[asark]

Food portions and being (or acting) unable to finish all but the daintiest serving sizes definitely has a class component to it, at least in the US. I think this behavior's shifted "down" a notch or so, alongside fitness-as-a-class-marker (see also: athleisure wear) as the upper-middle and more perceptive anxious/striving middle classes have latched onto it. In tech circle's I'd guess it's very common, they consisting largely of those two class groups (using a Fussellian system of classification, here).

Of course our meal serving sizes do probably vary more than in most (saner) countries. On the low end of the dining-out spectrum, one is often served enough food for two or more meals. There's an "if I don't feel stuffed to the point of nigh-immobility, I got ripped off" attitude in that sector of the market.