A high-fat, low-sugar food plan that still gains weight

For her partner, 10 September 2026, at his request. Targets: at least 2,200 kcal and 80 to 90 g protein a day, weight up from 51 kg. Estimates are conservative, as with the diary. The dietitian and GP should see this.

First, the honest position (two paragraphs, then the plan)

There is no evidence that a ketogenic diet slows chordoma or any related tumour, and the trials that tested ketogenic and fasting diets in cancer patients all produced weight loss, which is the one thing the patient cannot afford. The tumour is not fed by dietary carbohydrate; the body holds blood glucose steady whatever she eats. The European cancer nutrition guidelines advise against energy-restricting diets in anyone underweight or losing weight. Details and sources are in the metabolism brief.

So this plan is not a strict ketogenic diet. It is the version that answers what I think you are after: fat and protein doing most of the work, sugar and refined starch out, and some slow carbohydrate kept in, because it is what makes 2,200 kcal easy to eat, keeps her bowels moving on morphine, and keeps her blood sugar and blood pressure steady. If you want the strict version (under 50 g carbohydrate a day and ketosis), the same foods apply with the fruit, potato and oats removed; expect weight gain to be harder, constipation worse, and tell the anaesthetist, because a strict ketogenic diet is usually stopped a week before surgery.

The rules

1. Fat is the calorie lever: olive oil, butter, cream, cheese, nuts, nut butters, avocado, oily fish, egg yolks, coconut milk. Add fat to everything she already eats.
2. Protein at every meal and snack: eggs, fish, chicken, meat, Greek yoghurt, cheese, nuts. Aim for 25 to 30 g at each of three meals and 10 to 15 g in snacks.
3. Out: sugar, sweets, biscuits, cakes, fruit juice, fizzy drinks, white bread, most breakfast cereals. Honey and dates only in the smoothie if she wants them for taste.
4. Kept, in moderation: whole fruit (berries, one banana a day at most), potato and oats with fat and protein alongside, oatcakes, one slice of seeded bread. These carry the fibre her bowels need on morphine.
5. Small and often: six eating points a day. Appetite on morphine comes in windows; food should be ready before the window opens.
6. Fluids: 1.5 to 2 litres, more on diclofenac days. Full-fat milk counts as food.
7. Weigh once a week, same scales, morning. If weight falls two weeks running, the plan is wrong for her and the dietitian decides.

A day that reaches 2,300 kcal and 90 g protein (conservative estimates)

• On waking (with the morning doses): Greek yoghurt 150 g full-fat with 30 g mixed nuts and a few berries. 400 kcal, 20 g protein.
• Breakfast (about 09:00): two or three eggs scrambled in butter, 40 g cheese melted in, a handful of spinach; one slice of seeded toast with butter if she wants it. 550 kcal, 30 g.
• Mid-morning: the smoothie, made richer: 200 ml full-fat milk, 100 ml double cream, one tablespoon peanut butter, half a banana, a handful of spinach, one date if she wants it. 520 kcal, 14 g.
• Lunch (about 13:00): tinned mackerel or sardines in olive oil on two oatcakes with butter, or half an avocado with a boiled egg and olive oil. 450 kcal, 22 g.
• Afternoon: cheese and a few grapes, or a handful of nuts. 250 kcal, 10 g.
• Dinner (about 19:00): salmon, chicken thigh or mince cooked in olive oil or butter with green vegetables in butter; small potato or sweet potato with butter if wanted. 600 kcal, 35 g.
• Supper: full-fat milk warmed with a spoon of cream, or yoghurt and nuts again. 250 kcal, 8 g.
• Total: about 3,000 kcal, 139 g protein if all eaten; two thirds of it still clears both targets.

The pantry

Eggs, butter, double cream, full-fat milk, Greek yoghurt (10 percent fat), cheddar and brie, olive oil, coconut milk, avocados, mixed nuts and peanut butter, tinned oily fish, salmon fillets, chicken thighs, beef mince, spinach, broccoli, tenderstem, courgette, mushrooms, berries, bananas, oatcakes, seeded bread, potatoes and sweet potatoes, herbs and salt.

What to watch

• Bowels: fat and protein without fibre slow the gut, and morphine slows it further. Keep the vegetables, oats and a daily fruit; keep the senna; add a macrogol sachet if two days pass.
• Nausea on fat: if cream or oil turn her stomach at a dose peak, shift the richest items to the two hours before the next dose.
• Blood pressure: hers runs low; salt food properly and keep the fluids up.
• Weight: the only number that judges the plan.