What actually causes the swings
Water: sodium, carbs, and hormones each move water by 1–3 lbs.
Glycogen: each gram of stored carb pulls ~3 g of water. Refill the tank and you're up 2 lbs by lunch.
Gut contents: undigested food and stool routinely add 1–3 lbs.
Hormones: women can hold 3–5 lbs of water in the week before a period.
How to read the real trend
Weigh daily, same time, same conditions. Average the last 7 days.
Compare weekly averages, not daily numbers. Fat loss shows up as a slope, not a step.
Body-fat % or waist measurement once a week gives you a second data source when the scale stalls.
