High Calorie High Protein Diet: A Practical UK Guide

Written by James Frost, founder of Flaming Phoenix. Updated October 2026.

A high calorie high protein diet means eating 300 to 500 calories a day more than your body uses, with 1.2 to 1.6g of protein per kilogram of body weight. Spread it across three meals and two or three snacks, each built around a protein food. For a 70kg adult that is 84 to 112g of protein, and the worked UK day below reaches 3,013 calories and 120g.

This page is about how to eat that way; for lists of foods that carry both, see my guide to high calorie high protein foods.

What is a high calorie high protein diet?

A high calorie high protein diet is ordinary food arranged so every meal and snack carries more calories and more protein, usually without bigger plates. NHS trust leaflets give it for a small appetite or recent weight loss; it also suits older age and the weeks after a period of illness, and people training hard use it with bigger numbers.

Leaflets from Gateshead Health NHS Foundation Trust and East Lancashire Hospitals NHS Trust set out the method: eat every 2 to 3 hours, choose full-fat versions, and add protein and fat to food you already eat. If a doctor has told you to limit protein, follow that over anything here.

How much protein and how many calories do you need?

Most adults on this diet aim for 1.2 to 1.6g of protein per kilogram of body weight a day, and 300 to 500 calories above the intake that holds their weight steady.

The UK reference intake is 0.75g per kg, which the British Nutrition Foundation puts at 56g a day for a 75kg man; it notes athletes and older adults may need more, quoting 1.2 to 2.0g per kg for athletes. A 2018 review led by Robert Morton in the British Journal of Sports Medicine of 49 trials and 1,863 people found extra protein stopped adding muscle from resistance training at about 1.62g per kg a day, on average.

Protein targets by body weight

This table shows daily protein at each rate, multiplied out and rounded to the nearest gram.

Use 1.2 to stop losing weight or to gain slowly, and 1.6 if you lift weights or train most days. The protein calculator for weight gain works out your own figure.

Calories: maintenance plus 300 to 500

The NHS suggests adults who want to gain weight add around 300 to 500 calories a day. Against the NHS averages of 2,500 for a man and 2,000 for a woman, that is about 2,800 to 3,000 and 2,300 to 2,500, and more if you are tall or active. To stop losing weight, eat at maintenance and keep the protein. My guide to how many calories to gain weight works out maintenance properly.

How to structure meals and snacks

Build the day from three meals and two or three snacks, and give each one a protein food, a starchy base and some fat.

The British Dietetic Association notes that the body’s use of protein at one sitting levels off at around 20g of animal protein, or about 30g of plant protein, and advises spreading it through the day. In McCance and Widdowson values, 20 to 25g looks like this:

• 100g of raw chicken breast: 24g of protein.
• A 145g tin of tuna in brine, drained: 25g.
• Three medium eggs: about 19g.
• 80g of dry red lentils, cooked into a dahl: 20g.

Fat adds most of the extra calories in little space (a tablespoon of olive oil is 117 calories), and snacks of 300 to 400 calories with about 10g of protein, such as yoghurt with walnuts, fill the gaps. Keep milky drinks for between meals, as the NHS advises, so they do not fill the space a meal needs.

What does a 3,000 calorie high protein day look like?

A 3,000 calorie high protein day in the UK can be porridge, a jacket potato, spaghetti bolognese and three snacks, reaching 3,013 calories and 120g of protein.

It is sized for a 75kg adult: the NHS average of 2,500 calories for a man plus 500, and 75 × 1.6 = 120g of protein. Values come from the UK’s McCance and Widdowson tables (CoFID 2021), scaled and rounded: oats are 381 calories and 10.9g of protein per 100g, so 60g gives 229 and 7g.

By meal, that is 590 + 378 + 611 + 414 + 862 + 158 = 3,013 calories, and 21 + 12 + 24 + 13 + 42 + 8 = 120g of protein. Protein supplies 16% of the calories (120g × 4 = 480, and 480 ÷ 3,013 = 0.16).

For a 65kg adult, drop the afternoon toast (414 calories, 13g) and the walnuts (138, 3g): 2,461 calories and 104g, or 1.6g per kg. Other meals at this size are in my 3,000 calorie meal plan.

How to build a week-long high calorie high protein meal plan

To build a week-long high calorie high protein meal plan, keep the worked day’s snacks and rotate the meals; each swap below is within 100 calories of the one it replaces.

The table gives portions and values worked out as above (buttered means 10g of butter; stock and spices are left out).

One week, snacks included (950 calories and 33g a day):

• Monday: the worked day, cooking double bolognese and freezing half.
• Tuesday: eggs on toast, tuna sandwich, chilli (cook double).
• Wednesday: beans on toast, lentil soup and toastie, salmon.
• Thursday: porridge, jacket potato, Tuesday’s chilli.
• Friday: eggs on toast, tuna sandwich, chicken pasta bake.
• Saturday: beans on toast, lentil soup and toastie, dahl.
• Sunday: porridge, jacket potato, Monday’s bolognese.

Each day lands between 2,922 and 3,054 calories, with 120 to 150g of protein. For a plan built around the scales, see my weight gain meal plan.

How much does a high calorie high protein diet cost?

A high calorie high protein diet can cost under £3.50 a day: the worked day above comes to about £3.40 at Tesco prices, and its dearest item is the 100g of mince at 80p.

This table ranks protein foods by the cost of 20g of protein, using Tesco’s website on 22 October 2026 (cheapest own-label line, no Clubcard offers) and McCance and Widdowson values (pasta, oats and lentils weighed dry).

The cheapest protein arrives with the most calories: 20g from spaghetti costs 10p and brings 607 calories, against 58p and 88 calories from chicken. On this diet that works in your favour, though grain protein is used less well, so pair grains with milk, cheese, eggs or beans. For the same shop ranked by calories per penny, see cheap high calorie foods.

How to eat this way with a small appetite

With a small appetite, keep the same foods but serve smaller amounts more often, and enrich what is already on the plate instead of adding portions.

There is no figure to hit at each sitting: a few mouthfuls six times a day add up, and better days can carry more.

The simplest change is fortified milk: Gateshead’s leaflet stirs four heaped tablespoons of dried milk powder into a pint of full-fat milk, about 60g going by East Lancashire’s figure of 30g for two heaped tablespoons. The pint’s 358 calories and 19g of protein plus the powder’s 209 and 22g make 567 and 41g, so a 200ml glass holds about 200 calories and 14g, against 126 and 7g for plain milk.

• Use it in porridge, mash, sauces, custard and milky drinks.
• Serve the protein part of the plate first: the egg, fish or cheese.

For an older relative, my guide to protein for older adults covers the amounts for later life. If you, or someone you look after, are losing weight without trying, or eating has changed suddenly, speak to a GP, who can refer you to a dietitian.

How to eat this way when you are training hard

When you train hard, aim for about 1.6g of protein per kg in four or five servings of 20 to 30g, and let carbohydrate supply most of the extra calories.

Morton’s review put the average levelling-off point at 1.62g per kg, with an upper confidence limit of 2.2g. The British Nutrition Foundation notes that 20 to 25g of high-quality protein close to exercise seems enough to maximise muscle protein synthesis. After a session, a pint of whole milk adds 358 calories and 19g of protein for 41p. If the scale is stuck after three weeks, add carbohydrate, not protein: 75g of dry rice is 266 calories.

How do you know it is working?

It is working when your weight trend rises by about 0.25 to 0.5kg a week over at least three weeks, or holds steady if steady was the aim.

The arithmetic: 500 extra calories a day is 3,500 a week, the figure usually quoted for a pound (0.45kg), and 300 a day is 2,100, about 0.27kg. Weigh weekly, on the same day before breakfast, and judge the trend, since water and food in the gut move single readings. If nothing moves in three weeks, add 200 to 300 calories a day: a 250ml glass of whole milk (158) and 20g of walnuts (138) is 296. If you train, rising weights in your log are a second sign. If weight keeps falling even though you are eating more, see a GP. The wider picture is in my guide to how to gain weight.

Where do Phoenix Bars fit?

I make Phoenix Bars for days a kitchen cannot cover: up to 557 calories in only 120g, with up to 66g of carbohydrate and up to 19g of protein, in six flavours. That makes them a source of protein and no more: 19g of protein is 76 calories (19 × 4), about 14% of a bar’s calories, against 16% for the worked day. A bar adds calories in little space; the meals still carry the protein. It also stirs into warm milk as a porridge.

Harry Clough, who ran 650km from Edinburgh to London, ate them for breakfast and wrote that they were “a really good way to maximise my calorie intake without having to eat too much.” The range of high calorie bars is on the homepage.

Frequently asked questions

How do I get 100g of protein a day in the UK?

Give each meal a 20 to 30g protein food and add a dairy snack. In the worked day, porridge with milk and peanut butter (21g), a jacket potato with beans and Cheddar (24g), bolognese (42g) and a 150g pot of Greek-style yoghurt (9g) make 96g; a 250ml glass of milk brings it to 104g.

How do I eat 2,000 calories a day with plenty of protein?

Use the worked day without the afternoon toast, the walnuts and the evening milk, with 50g of spaghetti and a 150g potato. That comes to 2,036 calories and 89g of protein: 1.2 to 1.6g per kg for anyone weighing about 55 to 74kg.

What is a good high calorie high protein breakfast?

Overnight oats made with 80g of oats, 200g of Greek-style yoghurt, 150ml of whole milk and 20g of peanut butter come to about 787 calories and 30g of protein. Three eggs scrambled in butter on buttered toast, with a glass of orange juice, is 575 calories and 27g. My high calorie breakfast guide has more.

What are good high calorie high protein meals for bulking?

Pair a starchy base with 40g or more of protein and some fat: chilli con carne with rice and Cheddar is 891 calories and 45g, a chicken pasta bake 791 and 52g. Eat them alongside training and about 1.6g of protein per kg. My bulking meals guide has more.

Can you follow a high calorie high protein diet as a vegetarian or vegan?

Yes. Vegetarians keep eggs and dairy, and the red lentil dahl above is 866 calories and 33g. Vegans lean on lentils, beans, tofu, peanut butter and soya drink, which McCance and Widdowson lists at 3.1g of protein per 100ml (sweetened) against 3.4g for whole milk. Plant foods bring fibre that fills you up quickly, as Gateshead’s leaflet notes, so add oil and nut butter generously.

Sources: NHS, Healthy ways to gain weight; NHS, Understanding calories; British Nutrition Foundation, Protein; British Dietetic Association, One Blue Dot: protein; Morton RW and others, British Journal of Sports Medicine, 2018; Gateshead Health NHS Foundation Trust, High calorie, high protein diet; East Lancashire Hospitals NHS Trust, High energy high protein diet sheet; McCance and Widdowson’s Composition of Foods Integrated Dataset (CoFID) 2021; Tesco online prices, 22 October 2026.