Concerned about how much my brother and his partner eat and worried I won't have enough

I cook for a friend with serious “food noise” and eats endlessly. You have my sympathy. But kindly I’d say it’s your house, your rules. Don’t allow him to dominate the portions of meat / cheese etc: as others have suggested a few types of potatoes, loads of veg and double your gravy expectation. Good luck - it’s awful watching someone eat to excess at your own dinner table.

I think it's quite cruel to have let him get to this age without saying something, especially knowing he is aware he rubs people up the wrong way and you say he feels so negatively about that, haven't you or someone else talked to him about social etiquette?
I mean most people of reasonable intelligence that are large are aware if there is an underlying reason and to be fair this does sound like a reaction to his awful childhood but from what you say he seems nonplussed.
If he keeps going at this rate he won't be here for many Christmases will he.

This. Needs must.

It sounds as if you are going to have to be brutally blunt to your brother, in advance of the meal. Tell him that the food you have is enough to feed 14 people, and everyone else is as entitled to the food as he is so he is NOT to take it all. I'd ask him to serve himself and his partner AFTER everyone else, and to still leave some for others to possibly have seconds not just hoover the whole lot up.

If he is so lacking in self-awareness, the you will have to supplement by imposing your awareness on him. Actually, yes - I'd plate up rather than do a buffet, unless you're keen on pissing off everyone else there.

I agree with the pp who said do mash and roasties. This is what we do in Ireland and it helps sastisfy those with huge appetites.

I would have crisps/nuts/snacks out. Probably a wee round of blinis or crostini pre dinner. I would make the starter vegetable soup, with barley and lentils in (and have a tiny bowl myself- that is filling and I want space for the main event). Serve that with baskets of rolls. Plate dinner, but send out dishes of veg, mash, roasties.

I would have a tray of roasties, pibs and one of yorkies in the oven while eating to top up supplies. I would have the roasties and pibs a good bit of the way there in advance and have the second round of yorkies minis (i do in a mini muffin tin). Then that stuff only takes 10 mins.

I have fed 25 out of a single oven this way. I did have turkey and ham resting while I fid all the other oven stuff and I had some soup starters and some a prawn and salmon parcels, according to their preference. Good luck!

Give him and his partner a good talking to as this selfishness and greediness has repercussions on everyone else at the table.
Be blunt and leave no uncertainty - if he can’t handle that then it’s best he stays away.
I really couldn’t be doing with this level of behaviour.

We always do plated meals. There is nothing childlike about that. It's making sure everyone has a fair amount and any extra can be added from platters.

She means he’s fat. No point beating about the bush. It would be a miracle if he wasn’t fat, considering how much he eats.

My BIl and wife came to ours:, I had carved the meat (beef) into slices. It was 3 slices each, including children (7), BIL said to his wife take as much as you like as i had always done plenty (when I carved I did 3 pieces each) and they were the first. When the plate of meat reach DH and I, they had taken so much we had only one slice between us! Last time they had first serving. I have a catering background, an am very generous with portions, i.e. children under 5, 2 or 3 thick slices as parents do not want to take more. Lots of different dishes, normally at least 2 types of potatoes, plus yorkshire puds, and onion puds, 3 or 4 veggies. If you have my dinner there is no way to go hungry, including vegatians. 20 sitting down UK.

I'd plate up. But also manage expectations in advance. "Hey bro, really looking forward to seeing you both. Just to warn you, we have 14 people coming for dinner and quite a small oven, so their won't be big portions on offer and only e.g. 2 pigs in blankets each. I don't want you to go hungry, so if you think you'll want extras do you want to bring yourself some extra food that doesn't need oven space? Or if you have an air frier you can bring with you, I would happily do you an extra batch of roast potatoes"

I have a brother who can be a big eater. He’s not overweight though, just very muscular and spends a lot of time at the gym. The trick is to fill them with stodge before the main event. I bunged a frozen pepperoni pizza in the oven for him one Christmas Day, which he devoured about an hour before dinner was served. He hid in the kitchen eating it away from my mother’s disapproving looks 😁

"oi, greedy bastard brother - leave some for the rest of us!"

Surely you just tell him?? No way would that go unmentioned in our family

@wrenjay But then everyone suffers. A ‘like it or lump it “ attitude is hardly in the Christmas spirit is it?

Grip or no grip, the fact remains that these two greedy gits are liable to serve themselves so much meat etc there'll be no chance of a reasonable serving for everyone else.
OP has only so much cooker space, even if she did have the budget for thirteen turkeys.
She has every right to seek the smoothest, least likely to go wrong way to organise this expansive dinner.
(Next year she and DH will stick to Welsh Rabbit with a sprig of holly, if they've any sense!)

He sounds like a revolting greedy pig. I’d plate up. You can’t have people ending up without and nor should you have to spend fortunes so he can stuff his greedy face

Actually I agree.

I was struggling with the 8 yorkshire puddings while others went without, but 200 people and hardly any left?

😳

Indeed it isn’t. You are a non-paying guest, and should show a bit of gratitude instead of ☹️ at receiving a ready-loaded plate of delicious food.
Aren’t you overlooking OP’s very legitimate concerns?

And also leads to beheading your second wife (and only narrowly missing ditto the sixth because you’d died of this endless excess), and stealing all the monasteries’ riches, according to many modern historians!

And treat everyone like a Child? I wouldn’t be happy at being handed a plated meal. It’s not a restaurant

I don't believe for a second he ate enough food to feed 200 people. It sounds like they like very big portions, not that there's not enough food to satisfy them. Get a grip.

So I would plate up everyone with the same amount to start so everyone gets a bit of everything. Then put out plate of extras like roast potato's and yorkies so they can fill up on those. Don't let anyone go without.

Plate everyone's portion even if they get it cold: tuff as it is. Put extras in bowls far from them. even gravy. I worked in catering the saying was "give them plenty, one each, you are feed not to fatten". That is what you will be doing and will very much look good to the majority of your guests. They are greedy pigs, do not entertain their fat bellies and overfed egos.

Can the starter be more filling? Large soup bowls and crusty bread?

Put salad out in the table as bubbles whist the food cooks? Or similar?

Most people wait to save room for dinner.

Buy some frozen cocktail sausages as pad out the chipolatas.

Ask adults to wait whilst the parents dish up the kids food

Have extra puddings available for after.

So that would make 600 - 800 smallish slices. And OP's brother and his partner ate so much there was hardly any left for any one else?
Fucking hell. They should be in the Guiness Book of Records.