What a flat week actually means

The scale reports one quantity: how much you weigh at that moment. It does not distinguish between fat, water, muscle and the contents of your digestive system, and it has no way to tell you which of them moved.

Things that produce a flat week

• A salty couple of days, holding water that will leave on its own.
• New or harder training, which brings water into the muscles for a while.
• Genuinely eating more than you thought - the honest possibility, and the one worth checking first.
• Nothing at all. Bodies do not lose weight on a schedule.

How long is too long

My working rule is three weeks. Under three weeks I change nothing, because the noise on a weekly comparison is bigger than the signal I would be reacting to. Over three weeks I go back through the log and check my portions honestly before touching anything else, because that is where the answer has been every time so far.

What I try not to do is react on Tuesday to a number that will look different on Friday. Every adjustment made inside a flat week has, for me, made the record harder to read rather than the weight easier to lose.

The trend line is the fact. A single reading is a measurement with noise in it.

If it has been flat for a fortnight and you are still logging honestly, the boring answer is usually the right one: keep going and look again next week.