How many calories should you eat to lose fat

Fat loss comes down to one idea: eat a little less energy than you burn, consistently, for long enough. Everything else is detail. This article walks through how to find your own number instead of copying someone else's.

Energy balance, without the guilt

A calorie is a unit of energy, nothing more. When you take in less than your body uses, it makes up the difference from stored fat. That is the entire mechanism. It is not a moral test, and food is not something you have to earn or repay.

This matters because so much diet advice is wrapped in shame — "good" foods, "cheat" meals, days you have to make up for. None of that is physics. A brownie is not a failure and a salad is not a virtue; they are both just energy, in different amounts. Once you see calories as information rather than judgement, the whole thing gets calmer and a lot easier to stick to.

So the real question is not "what am I allowed to eat" but "how much energy does my body actually use" — and then, "how far below that should I sit."

Start with maintenance

Your maintenance calories — often called your TDEE, or total daily energy expenditure — are what you burn on an average day. It bundles four things: the energy to keep you alive at rest, the cost of digesting food, your deliberate exercise, and all the incidental movement in between (fidgeting, walking, standing).

You can't measure this perfectly at home, but you can estimate it well. A good calculator uses your height, weight, age, sex and activity level to land in the right neighbourhood.

Treat the result as a starting point, not a verdict. Two people with identical stats can differ by a few hundred calories a day, so the number the calculator gives you is a hypothesis to test — which is exactly what the next steps do.

That widget is the TDEE and calorie calculator, if you'd like to bookmark it. And when its estimate and your scale start to disagree — they will — how many calories to maintain your weight covers believing the scale.

Choose a deficit you can actually live with

Once you have maintenance, fat loss just means eating below it. The size of that gap sets your pace — and this is where most people overreach.

The safe range for fat loss runs to about 1% of your body weight a week. Within it, the deficit we'd actually recommend is the gentler half: 0.5–0.75% of your body weight per week. For someone around 80 kg (about 176 lb), that is about 0.4–0.6 kg (roughly 1–1.3 lb) a week. It feels slow. It is meant to. A moderate deficit lets you:

• Keep more muscle, so you lose fat rather than just weight.
• Stay strong in the gym and energetic in daily life.
• Eat enough protein and fibre to feel full instead of ravenous.
• Have the mental slack to keep going for months, not days.

How big should your calorie deficit be, in numbers

A kilogram of body fat is worth roughly 7,700 calories. That figure is a rule of thumb rather than a law — it assumes a fixed body that doesn't adapt, and yours does — but it is close enough to turn the weekly pace above into a daily gap you can aim at. Rounded, and read against your current weight rather than your goal weight:

• 60 kg (132 lb) — 0.30–0.45 kg a week, a deficit of about 330–500 calories a day
• 70 kg (154 lb) — 0.35–0.53 kg a week, about 385–575 a day
• 80 kg (176 lb) — 0.40–0.60 kg a week, about 440–660 a day
• 90 kg (198 lb) — 0.45–0.68 kg a week, about 495–740 a day
• 100 kg (220 lb) — 0.50–0.75 kg a week, about 550–825 a day

Two things to notice. The bigger you are, the bigger a deficit you can carry comfortably — which is why a number copied from a smaller friend leaves you hungry for no extra progress. And every one of these shrinks as you do: recalculate against your current weight every 5 kg or so, or the deficit quietly becomes maintenance.

There is a floor, and it isn't the same for everyone

Subtracting a deficit from maintenance can produce a number that is simply too low to eat well on, and the smaller you are the sooner that happens. So there's a floor underneath all of this — and it scales with your body rather than being one figure for everybody.

The practical version: don't plan to eat much below your own resting burn, meaning what your body costs before you move at all. For most people that lands somewhere between 1,200 and 1,600 calories a day. If the arithmetic keeps putting you under that, the answer isn't a smaller number — it's a smaller deficit and a longer timeline, or a conversation with a doctor. Sustained very low intakes are where muscle loss, nutrient gaps and the rebound all live, and they buy you nothing that patience wouldn't.

Crash diets do the opposite. Cut too hard and you lose more muscle, tank your energy, wreck your training, and set yourself up for the all-or-nothing rebound that undoes the whole effort. The aggressive plan almost always loses to the boring one, because the boring one is the one you finish. Why crash diets fail makes that case in full.

The number is a hypothesis, not a rule

Here is the part almost no diet plan tells you: your starting calorie target is a best guess, and best guesses are meant to be revised.

Your body responds. As you lose weight you burn a little less, and your day-to-day movement quietly adjusts too. So the target that worked in week one may stall by week five. That is not failure or a "broken metabolism" — it is the normal, expected drift of a moving system.

The fix is to watch your weight trend, not any single morning's number, which bounces around with water, salt and sleep. Take the average of your daily weigh-ins across one to two weeks and compare it to the fortnight before. If the trend is falling at roughly the pace you planned, hold steady. If it has flattened for two weeks straight, nudge intake down a little — 100 to 150 calories — and watch again. You are running a slow, patient experiment on a sample size of one: you.

If it has been flat for longer than that, the answer usually isn't a smaller number: why am I not losing weight in a calorie deficit runs through the six explanations in the order they're actually likely. And if the reason your logging has gone patchy is the kitchen scale, you can track calories without weighing your food accurately enough for this loop to work.

Let the target adjust to you

That loop — set a number, watch the trend, adjust — is the whole game, and it is easy to describe and tedious to do by hand. That is where Sophia comes in. She sets your starting calorie target from your own numbers and goals, then reads your weight trend each week and moves the target accordingly — easing off when you need a break, nudging it when things stall — so you always know what to eat next without doing the maths yourself.