Everyone knows what a deficit is. Far fewer know it doesn't have to happen every day — which is the bit that decides whether they stick with it.
Eat less energy than you use and your body makes up the difference from stored fat. A pound of fat is roughly 3,500 calories, so a deficit of 500 a day comes to about a pound a week.
That's the whole mechanism. No food is special, nothing is forbidden, and nothing you eat after 6pm behaves differently from the same food at noon.
A deficit is a weekly average, not a daily rule. Your body doesn't settle the books at midnight — that's a calendar convention, not biology.
So a target of 2,000 a day is really 14,000 a week, and nothing requires it to come out in seven equal slices. Run Monday to Friday at 1,800, have 3,000 on Saturday, and the week is identical.
That single reframe is the difference between a plan that survives a wedding and one that doesn't.
Treat every day as pass or fail and you'll fail about once a week, because life contains birthdays. And the failure isn't the meal — it's concluding the week is ruined, which usually costs another three days.
Judge it weekly and a big Saturday stops being a failure. It's a Saturday you paid for.
Weigh daily and look at the line, not the dots. Day-to-day weight is mostly water, salt and timing. Across a fortnight the trend tells you the truth; a single morning never does.
Leeway is a free tool that does this arithmetic for you. Put what's coming up into the week and it spreads the cost across the days around it, with a floor it won't plan below.
Open the planner — freeLeeway is a planning tool, not medical or dietary advice. Calorie figures are typical estimates and vary by brand, measure and recipe. It isn't suitable if you have, or have had, an eating disorder or a disordered relationship with food. If you're unsure what a safe calorie target is for you, speak to a GP or registered dietitian first.