How many calories do I need a day?

The number on the side of the packet — 2,000 for women, 2,500 for men — is the most quoted figure in British nutrition and the most misunderstood. Here is where it comes from, why it is probably not your number, and how to find yours.

The NHS guideline

The NHS puts the recommended daily calorie intake at around 2,500 kcal for men and 2,000 kcal for women. That is an average for an average adult doing average activity. If you are 6ft 2 and carry blocks for a living, or 5ft 2 and sit at a desk, the average is a long way from you.

What changes your number

• Size. Bigger bodies burn more at rest. This is the biggest factor.
• Activity. Not just training — the difference between a site job and a desk job can be several hundred calories a day.
• Muscle. More muscle, more burn, though the effect is smaller than the adverts suggest.
• Age. Requirements drift down slowly through adulthood, mostly because activity drops.

The two-week method

Online calculators guess. Your body does not. The only accurate way to find your maintenance calories is to eat a consistent amount for two weeks and watch the scale:

1. Pick a number — the NHS figure is fine as a start.
2. Eat roughly that every day for 14 days. Track it, honestly, including the Friday takeaway.
3. Weigh yourself each morning and average each week.
4. Weight steady: that is your maintenance. Going up: your maintenance is lower. Going down: it is higher.

Two weeks of boring consistency beats any app's estimate.

How much to cut to lose fat

The NHS weight loss plan works on a deficit of around 600 kcal a day — roughly 1,900 for men and 1,400 for women from the guideline figures — which is designed to lose about 0.5–1kg (1–2lb) a week. That is the sensible band. Cut harder and you lose muscle, feel terrible and rebound. If you train, keep protein high and take the deficit mostly from the foods that were not doing much for you anyway. Our protein guide has the numbers.

How much to add to build muscle

A small surplus — 200–300 kcal above maintenance — is enough. A big surplus builds fat faster than muscle. If you are new to training you can build muscle at maintenance, or even in a small deficit, so do not rush to "bulk".

Why this is easier with someone doing the sums

Most people know roughly what to do and still do not do it, because the arithmetic every day is a chore and the number needs adjusting as you change. The AI coach sets your calories from your actual weigh-ins, adjusts them weekly, and builds the meals to hit them — around your shifts, not a textbook day. £19.99 a month, first 30 days free.

FAQs

Is 1,200 calories a day enough?

For most adults, no. It is below what the NHS recommends without medical supervision and usually ends in a rebound.

Do I need to count calories to lose weight?

Not forever. Two weeks of counting teaches most people what a normal day looks like; after that, a plan does the counting for you.

Are the calories on food labels accurate?

Roughly. UK labels are allowed a tolerance, and restaurant figures are rougher still. Consistency matters more than precision.

Guideline figures: NHS, "Understanding calories" and the NHS weight loss plan. This is general information, not medical advice — check with a GP before a big change if you have a health condition.