Sunday Roast with Diabetes: CGM-Backed Plate Rules That Work

Nutrition · 6 · April 20, 2026

A proper Sunday roast is not the enemy. What's on your plate, in what proportion, and what you do after — those decide the damage. Two weeks of roast dinners at home and at three different gastropubs, every meal logged through a continuous glucose monitor. Here are the plate rules that held up.

Why the roast became a problem

A plate of meat, a few potatoes, some vegetables, and gravy is not a diabetic emergency. A plate of meat, four roast potatoes, two Yorkshires, a pile of stuffing, and gravy made from a packet with sugar in it — that is a different meal, served by the same pub, under the same name. Sunday roast has drifted. Each individual element is defensible; the stack as it arrives is not.

My first pub roast of the experiment, eaten with the same enthusiasm I've always eaten one, produced a CGM peak of 197 mg/dL and a crash back to 73 three hours later. The same plate, rebuilt at home with the swaps below, peaked at 148 and left me awake for the second half of the match.

The plate, part by part

The meat: not the problem

Roast beef, lamb, chicken, or pork are essentially neutral for blood sugar. Go to town. The only caveat is that fatty cuts served with a thick glaze or a honey crust pick up carbs you may not notice. Plain roast, thick slice, you are fine.

Roast potatoes: depends on the portion

A standard roast potato is about 80 g. One potato is a starch side. Four potatoes is a dedicated carb course hiding on your meat plate. My CGM data across two weeks suggests:

• One medium roast potato: average peak contribution 8–12 mg/dL.
• Two: 20–28 mg/dL.
• Three or four: 35–55 mg/dL.

Fresh hot roast potatoes spike more than reheated day-old ones. The resistant starch that forms in the fridge is real. Cold Monday potato hash for lunch is a better deal than a fifth hot potato on Sunday.

Yorkshire puddings: smaller than you think

They look innocent. They are made of flour, eggs, and milk, which you might read as low-spike. In my data, a single medium Yorkshire added 15–25 mg/dL to the peak — higher per gram than the potato. The fluffy texture means fast digestion. One is fine. A trio at a carvery is not.

Stuffing: the quiet villain

Compressed bread, butter, onion, and often sugar in the prepared varieties. The standard pub ladleful read on my CGM like a small slice of bread pudding. If you want to keep an indulgence on the plate, keep the Yorkshire and skip the stuffing. The stuffing is almost always the biggest single carbohydrate source on a pub roast plate that nobody counts.

Vegetables: eat more of these

Buttered carrots, parsnips, broccoli, cabbage, green beans, peas. Generally low-spike, high-fibre, and a second helping of any of them is the easiest way to feel satisfied without another potato. The one to watch is mashed swede or mashed parsnip with honey — the sweet root mashes creep into potato territory.

Gravy: home-made is fine, packet is not

Home-made gravy from the roasting pan is drippings, a little flour, stock, and seasoning — essentially neutral. Packet gravy often contains added sugar, starch thickeners, and salt to carry them. Pub gravy varies. If you love gravy, ask the bartender if it's home-made; most honest chefs will tell you.

Bread sauce: a tolerable small serving

A tablespoon is fine. The full ramekin they bring you at a proper pub is a whole separate slice of bread.

The six swaps that held up across every roast

1. One Yorkshire, not three. If the pub serves three, eat one and cut the others for your table partner who never gets asked.
2. Two potatoes, not four. Ask for a double portion of vegetables instead. Most pubs will swap without comment.
3. Skip the stuffing. The single biggest lever on the plate.
4. Home-made gravy only. If you cannot confirm, a thin line of gravy and stop there.
5. Eat the meat and vegetables first. Get through the protein and greens before starting on the starches. This is the Japanese meal-order research applied to a roast. It works.
6. Walk after. Ten to fifteen minutes. Around the block, along the river, between the pub and the car the long way. Every single time my post-roast curve was better with a walk and worse without.

A note on the pub economy

The reason pub roasts have gotten carb-heavier over fifteen years is simple: potatoes, Yorkshires, and stuffing are cheap; beef and lamb are expensive. The plate you get has drifted because the margin math pushed it there. Do not feel guilty asking for extra vegetables and one fewer potato. You are not asking for less food. You are asking for a redistribution.

What I did not compromise on

The roast itself. The vegetables. A proper home-made gravy. A single Yorkshire. A glass of wine with it if I wanted one. The pub, the match, the Sunday. Blood glucose control at a Sunday roast is not a case against tradition. It is a case for paying attention to what the plate has become and asking, politely, for the version the name used to describe.

Next week: the pub ploughman's. Early signs: the cheese is fine, the pickled onions are fine, the bread is the whole story.

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