Three weeks of progress, then nothing. The instinct is to assume something has broken — metabolism, hormones, the diet itself. Usually nothing has. Here are the four explanations, in the order they are likely.
1. It has not actually stopped
Body weight swings by one to two kilograms across a day on water, food in transit, salt and, for women, the menstrual cycle. Against that noise, a fortnight of real loss at 0.25 kg a week is invisible. If you are comparing two single mornings, you are not measuring weight loss — you are measuring hydration. Compare weekly averages instead, and give it three weeks before concluding anything.
2. The target moved
A smaller body burns less. Lose 6 kg and the deficit that produced the loss has quietly shrunk to almost nothing — the plan is still working exactly as designed, the design just expired. The NIH Body Weight Planner2 is unusual in modelling this properly; most calculators hand you one number as if it were permanent.
3. Portions drifted
Nobody notices this happening. The oil goes in more generously, the "handful" grows, the weekend stops being counted. Two hundred extra calories a day is enough to erase a 0.3 kg-a-week deficit entirely, and two hundred calories is a tablespoon of oil and a biscuit.
4. Everything else got quieter
People in a deficit move less without deciding to: fewer steps, less fidgeting, an earlier sofa. It is not laziness, it is the body defending its budget. The NHS activity guidelines3 are worth keeping an eye on for exactly this reason — the baseline is easy to lose without noticing.
What to do, in order
- Wait three weeks. Most plateaus resolve themselves by being measured properly.
- Re-weigh your food for one week. Not forever — one week, to see where the drift went.
- Recalculate the target for the body you have now. Not the one you started with.
- Add steps before cutting food. Getting the baseline back costs you nothing on the plate.
- Consider a maintenance fortnight. Eating at your new maintenance for two weeks is not a failure, and people who take one are more likely to still be going in six months — the pattern over months is what decides the result, as Harvard's healthy weight guidance4 keeps pointing out.
The one thing not to do
Do not cut another 500 calories out of a diet that is already restricted. That is how a plateau becomes a binge, and how a fortnight of flat becomes a month of lost ground. If nothing has moved in a month of honest measurement, the NHS weight-management pages1 are the right place to look next.
