Belgian winter food is stews, braises, roasted meats, cheese, and things cooked for a long time in red wine or beer. Most of this is excellent for keto. The season does most of the work for you, in terms of aligning what you want to eat with what you’re supposed to eat.
February is also grey and cold in a specific Brussels way — not dramatically cold, but persistently damp and dark in a way that makes you want to eat something heavy and sit near a radiator. This is compatible with keto. The problem is that everyone around you is also eating waffles and drinking hot chocolate, and somehow in winter that’s harder to ignore than in summer.
Winter food that works
Stews and braises are the natural winter food and they’re almost all keto-friendly once you detach them from the frites or bread they’re normally served with. Carbonnade flamande, stoofvlees, slow-cooked lamb, a braised pork shoulder — the cooking process reduces any carbs from wine or beer significantly, and the resulting dish is fat and protein. Serve with celeriac mash or roasted root vegetables in moderation and you’ve got a proper winter meal.
Root vegetables are worth addressing. Carrots, parsnips, and celeriac have more carbs than leafy greens but significantly fewer than potatoes. In a stew or roasted alongside meat they don’t add up to much, and they’re what you actually want to eat in February. Turnips and swede are particularly good roasted in butter. Winter salads with endive and radicchio — very Belgian, very good — are low-carb and feel substantial in a way summer leaves don’t.
Cheese is a winter food in Belgium. A good piece of Herve or aged Chimay with a glass of dry red wine is a reasonable evening. The fondue places that appear in Brussels in December and January are mostly fine on keto — the cheese itself has no meaningful carbs, the bread for dipping is the problem. You can dip vegetables instead. You can also just eat the fondue with a fork, which nobody will judge you for once they’ve seen how the cheese tastes.
The winter market problem
The Plaisirs d’Hiver market and the various smaller winter markets around Brussels run from late November through January, and the food stalls are almost entirely waffles, hot chocolate, vin chaud, and churros. It’s a genuine minefield if you’re trying to stay strict.
There are grilled meat stalls at most of the larger markets. There are usually cheese stalls. The Dutch and Flemish stalls sometimes carry things like smoked fish or aged cheese. You can eat at a winter market on keto but you’re working harder than in summer.
The vin chaud question comes up every year. It has sugar in it — typically quite a lot. Whether it’s worth it during a cold evening at the Marché de Noël is something only you can decide, and making it a whole drama either way seems like the wrong approach to December.