800 Calorie Meal Plan UK — Is It Safe? What to Eat

An 800 calorie daily intake is classed as a Very Low Calorie Diet (VLCD) by the NHS and NICE — the lowest level recommended for any structured weight loss approach. At this level, significant and rapid weight loss occurs, but so does significant risk of muscle loss, nutritional deficiency, and metabolic adaptation if the approach is not structured correctly. This guide covers when it is appropriate, what the NHS actually recommends, and what to eat to make it as safe as possible.

Medical guidance: NICE and the NHS advise against routinely following a VLCD below 800 calories without GP or dietitian supervision. The NHS recommends VLCDs only for short periods (typically 12 weeks) and usually as part of a structured clinical programme, not an independent diet. Speak to your GP before starting a very low calorie diet.

Quick answer: 800 calories per day can produce rapid weight loss of 3–5lbs per week in the short term. The NHS uses it as part of supervised programmes for people with type 2 diabetes and obesity. Without supervision, the main risks are muscle loss (protein intake must be very high), nutritional deficiency, and metabolic slowdown. It is not appropriate as a long-term approach.

When 800 calories is used clinically in the UK

NHS Type 2 Diabetes remission programmes: the NHS Diabetes Prevention Programme and the DiRECT trial both used 800 calorie meal replacement diets with clinical supervision — achieving Type 2 diabetes remission in approximately 50% of participants at 12 months
Pre-operative weight loss: some NHS surgical teams use very low calorie diets for 2–4 weeks before bariatric surgery to reduce liver size and surgical risk
Medically supervised obesity treatment: under dietitian supervision as part of a structured programme, not independently

Who should NOT attempt 800 calories independently

Anyone pregnant or breastfeeding
Anyone under 18
Anyone with a history of eating disorders
Anyone with Type 1 diabetes without medical supervision
Anyone on medication whose dose depends on food intake (including GLP-1 medication — speak to your prescriber)
Anyone with a BMI under 30 without specific clinical reason

What to eat if following 800 calories under supervision

At 800 calories, protein must be prioritised above everything else — minimum 80–100g per day to limit muscle loss. This leaves very little room for carbohydrates or fat.

Meal	Option	Protein	Calories
Breakfast	Protein shake (25g protein powder + water) + 100g Greek yoghurt	35g	~200 kcal
Lunch	Tinned tuna (1 tin) + large mixed salad + lemon juice	28g	~180 kcal
Dinner	Chicken breast (120g) + steamed broccoli + courgette	38g	~250 kcal
Snack	Cottage cheese (100g)	11g	~100 kcal
Total		~112g	~730 kcal

Why most people searching for an 800 calorie plan should reconsider

The majority of people searching for an 800 calorie plan would achieve better long-term results at 1,200–1,500 calories. Research comparing VLCDs to moderate calorie deficits consistently shows similar total weight loss at 12 months because higher dropout rates on VLCDs cancel out the faster initial rate. The person who eats 1,400 calories consistently for a year loses more weight than the person who eats 800 calories for 8 weeks then abandons the approach.

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Also see: 1,000 Calorie Meal Plan UK | 1,200 Calorie Meal Plan UK | Why Am I Not Losing Weight Eating Less?