Fat loss, explained like you're not a scientist

A calorie is a unit of energy. Everything else on this page builds from that.

A calorie is a unit of energy. That's it. Like litres for fuel or metres for distance. Not a toxin, not a villain, just a measurement.

Your body burns a certain amount of energy every day keeping you alive, moving, and training. Eat less than you burn, and your body takes the difference out of stored fat. That's fat loss. The whole thing.

In the two-year CALERIE trial, 34 adults prescribed a 25% calorie cut achieved about 15%, a useful reminder that the best deficit is one you can sustain.

Keto, fasting, slimming clubs, "clean eating": every one of them only works because it puts you in that deficit. Nothing else.

Same goes for anything aimed at one bit of you. No exercise burns belly fat on its own, and how to lose belly fat goes through what actually shifts it, and why it is the last place to go.

Training adds to that burn, but less than most people assume, and the pace you pick changes what you get out of it. The cardio zones, in plain English, if you want that side of it.

So the first real step is knowing your number: how much your body burns per day. Pair that with a body-fat estimate only if it gives you another repeatable measure; it is a trend tool, not a score to chase.

Builds on Lesson 1: same deficit, but this is how you survive it without white-knuckling hunger.

Hunger is what kills diets, not lack of willpower. The fix is picking foods that fill your plate and your stomach for very few calories.

400 calories of chicken, spuds and veg is a full dinner you can't finish. 400 calories of chocolate is six squares and you're hungry in an hour.

• Heavy hitters: potatoes, chicken and turkey, white fish, eggs, prawns, 0% Greek yogurt
• Plate fillers: any veg, salads, soups, berries
• Snack saves: popcorn instead of crisps, big bowl of strawberries instead of biscuits

Nothing on that list is a supplement, and that's deliberate: food does this job. If you're wondering what is worth buying, only four supplements have real evidence behind them and the rest of the aisle is marketing.

Builds on Lesson 1: your number's only useful if what you log actually matches what you eat.

Your eyes lie about portions. Everyone's do. A "drizzle" of olive oil is often 200 calories. A "bowl" of cereal is usually two servings.

A cheap kitchen scale ends the argument.

Weigh the oil, the rice, the cereal for a few weeks and two things happen: your numbers start matching reality, and you learn what a real portion looks like so you can eventually eyeball it. Where do the numbers come from? Scan the barcode.

Builds on Lessons 1–3: the number's right, the weighing's right; this is what stops it falling apart by Thursday.

The worst food decisions happen at 6pm, starving, staring into the fridge.

• Repeat breakfasts and lunches. Same porridge, same lunch, most days. Boring? It's two meals. Save the variety for dinner.
• Cook once, eat twice. Double the mince, tomorrow's lunch is done.
• Shop from a list written after you've eaten, never while hungry.
• Log the day in the morning, not after eating. Now it's a plan, not a confession.

Doesn't touch your calorie number directly. It decides how easy that number is to hold.

Run on five or six hours and your hunger hormones shift: you are hungrier, you crave sugar and carbs harder, and the deficit you managed easily last week feels impossible.

Nothing about your calorie target changed. Your ability to hold it did.

It runs the other way too: training is one of the better things going for sleep and for mood. What exercise actually does for your head is the honest version of that, research and caveats included.

Builds on Lesson 2: same principle, applied to the meals you already eat, not new ones.

You don't need new meals. Keep the dinners you like and swap the expensive-calorie parts for cheaper ones:

Same meals, hundreds of calories less. Nothing boring about it.

Every lesson above, on one plate. If this makes sense, you're ready for Day One.

Theory is grand. Here's the practice: a full example week, 3 meals a day, every item from Aldi or Lidl (one Tesco item — the Philadelphia Protein cream cheese), macros computed from the labels. The three rows below add up to 2170 kcal and 193g protein:

Both versions use everyday own-brand items. The full page has both weeks, the shopping list, a swaps table and a batch-cooking plan.

Know your number, eat filling food, weigh it, plan it, swap it. That's the whole game.