To gain 1 kg of fat, you'd have to eat about 7,000 kcal more than you burn. Nobody does that in one dinner. So when the scale jumps 1 kg overnight, what went up was almost always something else.
What makes your weight fluctuate
- Salt: a saltier meal makes your body hold water for a day or two.
- Carbs: your body stores carbs in muscle along with water. After a meal with more pasta or bread, the number rises.
- Digestion: what's still in transit weighs something. Constipation can add hundreds of grams.
- Menstrual cycle: fluid retention is common in the days before your period.
- New workout: muscles that worked harder hold water to recover.
- Time and clothes: weighing at night, after eating and dressed, gives a different number.
What to do
Nothing. Swings of 0.5 to 1.5 kg (1 to 3 lb) are normal and go away on their own within a few days. What matters is the trend over weeks.
- Weigh yourself on the same day of the week, when you wake up, after the bathroom.
- Compare week to week, not day to day.
- If the week was salty or it's the week before your period, wait for the next weigh-in before drawing conclusions.
The daily scale measures water. The weekly scale, always done the same way, shows the path.
This content is for information only and doesn't replace advice from a doctor or dietitian.
