One kg of body fat stores roughly 7,700 kcal. To lose 0.5 kg of fat a week, you need an average deficit of about 550 kcal a day. The maths is clean, but adherence is the actual variable. Most cuts fail at the size of the deficit, not the duration.
Pick a rate you will stick to
0.5 to 0.75% of body weight per week is the sustainable range. For an 80 kg person that is 400 to 600 g a week, or a 450 to 650 kcal daily deficit. Going faster works for two to three weeks, then sleep and training quality drop, and weight loss stalls because you start moving less without noticing. Anything beyond 1% per week should be capped at four to six weeks before a maintenance break.
What to do when the scale stalls
Plateaus after week three are normal. Your body adapts: NEAT drops, water shifts, glycogen depletes. Wait a full 10 days before adjusting. If the 10-day average weight has not moved, drop another 100 to 150 kcal per day, not 500. If you have already cut twice and feel cooked, take a 10 to 14 day diet break at maintenance. You will lose more fat across the year by alternating cuts and breaks than by trying to grind one long deficit.
