How Many Calories Should You Eat to Lose Weight?

It’s the first question almost everyone asks when they decide to lose a bit of weight: how many calories should I actually eat? The honest answer is that there’s no single magic number printed on a card somewhere with your name on it. But there is a sensible range you can work out in a few minutes, and it’s more useful than any generic “eat 1,200 calories” advice you’ve seen floating around.

Let’s walk through how to find your number, why a gentler deficit usually wins, and how to adjust when the scale stops moving.

Start with your maintenance calories

Before you can eat in a deficit, you need to know roughly what your body burns in a day. This is your total daily energy expenditure, or TDEE. It’s made up of a few parts:

• Basal metabolic rate (BMR): what you’d burn lying in bed all day. For most adults this is the biggest chunk, commonly around 60–70% of the total, though it varies from person to person.
• Daily movement and exercise: walking, workouts, fidgeting, standing.
• Digesting food: yes, breaking down meals costs a small amount of energy, especially protein.

A quick estimate: multiply your body weight in kilograms by roughly 28–32 if you’re lightly active. Someone weighing 75kg who does a bit of walking might land somewhere around 2,100–2,400 calories a day to maintain. It’s a rough ballpark, not gospel — individual needs vary with age, sex, body composition and activity — but it gives you a starting line. Online TDEE calculators using equations like Mifflin–St Jeor can give a slightly more tailored estimate.

The most accurate calorie target isn’t the one from a formula. It’s the one you adjust based on what actually happens to your weight over two or three weeks.

Set a realistic deficit

To lose fat, you eat fewer calories than you burn. The size of that gap decides how fast you lose and, crucially, how sustainable it feels.

A deficit of around 300–500 calories per day is a reasonable target for most people. That tends to produce very roughly 0.25–0.5kg of loss per week, though the exact figure varies. Slow? A little. But it’s the pace that helps you keep your energy up, hold on to more muscle, and not feel like you’re white-knuckling every meal.

Aggressive cuts of 1,000+ calories can produce faster loss short-term, but they tend to come with a cost: more hunger, more muscle loss, and a higher chance of rebounding the moment life gets busy. For general guidance, the NHS weight-loss plan suggests target daily calories of around 1,400 for women and around 1,900 for men, but those are broad averages rather than personalised targets — and larger, more active people often need more.

A worked example

Say your maintenance is 2,300 calories:

1. Subtract 400 for a moderate deficit.
2. Your target becomes roughly 1,900 calories a day.
3. Track for two to three weeks and weigh yourself under consistent conditions.
4. Lost weight steadily? Stay put. Nothing moved? Trim another 150–200.

Simple, and it beats guessing.

Don’t drop too low

There’s a floor worth respecting. Eating extremely low-calorie for long stretches makes it hard to get enough protein, fibre, vitamins and minerals, and it can leave you exhausted and irritable. As a rough guide, very low-calorie diets — often defined as under about 800 calories a day — should only be followed under medical supervision. More generally, dropping well below roughly 1,200 calories for women or 1,500 for men isn’t recommended without professional guidance.

Very low intakes also tend to backfire for many people. You may get hungrier, move less without realising it, and eventually find the diet hard to stick with. A moderate deficit you can hold for months will usually beat a punishing one you abandon in a fortnight.

Protein and food quality still matter

Calories largely decide whether you lose weight. What those calories are made of has a big influence on how you feel while doing it.

• Protein helps keep you fuller for longer and helps protect muscle while you’re in a deficit. A practical guide is a palm-sized portion at each meal; for people who train, research often suggests roughly 1.6–2.2g per kg of body weight, though needs vary.
• Fibre from vegetables, fruit, beans and wholegrains adds volume and slows digestion, so a lower-calorie plate still feels like a proper meal.
• Fats and carbs fill in the rest based on what you enjoy and can stick with. There’s no need to fear either.

Two meals can both hit 1,900 calories: one might leave you starving by 3pm, the other keeps you steady. The difference often comes down to protein and fibre.

Why tracking actually helps

Many of us underestimate how much we eat — not because we’re dishonest, but because the splash of oil, the handful of nuts, the “just a taste” while cooking all add up quietly. Writing it down for even a couple of weeks can turn your calorie target from a guess into something you can steer.

You don’t have to log forever. Many people track closely for a few weeks, learn what their usual meals cost, and then coast on that knowledge. The number on the label matters less than the habit of paying attention. (If tracking ever starts to feel obsessive or anxiety-provoking, it’s worth stepping back — see the note at the end.)

When to adjust

Weight loss is rarely a smooth line. Water shifts, hormones, salt, and a big meal the night before can all nudge the scale. Judge progress over two to four weeks, not day to day.

If you’ve genuinely stalled for three weeks or more at the same intake, that’s a cue to either trim 150–200 calories or add a little more daily movement. As you get lighter, your maintenance tends to drop too, so the target that worked at the start will likely need a small tweak later on.

This article is for general information and isn’t medical advice. If you have a health condition, take medication, are pregnant or breastfeeding, or have any history of disordered eating, talk to a GP or a registered dietitian before starting a calorie deficit.