Since I'm not a native english speaker - I can only guess what you mean with pug-raiding.
BUT: it is a matter of facts that people have some "scotish mind"
It seems (sometimes) that the highest approach is to save gold in any possible way.
Or let's call it "mind difference" between atendees and leaders.
Leaders think - oh, a new boss - lots of training: do the best, also with food and flasks.
And in opposite atendees think: oh, a new boss - we will whipe a lot: let's reduce the (personal) costs of the whipes :)
I still have to select every raid member to if they ate correct buff-food
or simply "Nagrand Cherry" just to show up they ate something.
The purpose of BigBrother is to remind your raiders to buff, not to police them and punish. If you truly have a major problem with your raiders sabotaging buff checks:
Step 1) Tell all raiders to bring appropriate food.
Step 2) Check buffs manually once; anyone with 'lazy' food gets warning
Step 3) Check manually on next attempt; kick out anyone who does it again. They aren't interested in helping the raid, and shouldn't come.
Should be enough to avoid having to manually check the food buff for a while. ;)
Is it possible to show more detailed information on that tooltip or are there technical limitations that prevent this.
I'm unsure if the stats on the Well Fed buff are visible to an addon like BigBrother; it may only be designed for detecting the 'Well Fed' name of the buff. If that's the case, adding specific food detection might require a redesign, and would then be more trouble than it's worth.