How often should you recalculate your calories?
Your calorie target is built from your weight, so it quietly goes stale as you get lighter. Refresh it about every five kilos you lose, or every four to six weeks, whichever comes first.
You started well. Each week the scale dipped. Now you wonder: should I change my calorie number? The target you got on day one felt perfect. But your body is changing. So the number that fits it is changing too. This short read tells you how often to refresh it. And how often not to.
To stay accurate, you should recalculate your calories every single day.
mostly falsemostly false
Your weight hops up and down each day. Water, salt, a heavy tiffin, even chai can move it. One kilo of that day-to-day swing shifts your maths by only about 10 calories. That is noise, not a real change. If you recalculate daily, you chase the noise. Your body has not changed. Only the water has. Refresh on a rhythm, not on a single morning. BMR means the calories your body burns just to stay alive. It does not swing that fast.
Every kilo you lose drops your burn by about 10 kcal a day
Here is the honest maths. The most-used calorie rule is the Mifflin-St Jeor equation. It gives your body about 10 calories per kilo, each day, at rest. So when one kilo is gone, you burn about 10 calories less a day. Lose five kilos, and that is about 50 calories a day gone. That is like half a roti your old plan now miscounts. Scientists also found a small extra drop. It is called metabolic adaptation. That means your body burns a little less than the weight maths predicts. One study measured about a 46 calorie-a-day extra drop after people lost 12.5 kilos. So the real drift can be even bigger than the maths alone.
How often: four rhythms compared
How to make refreshing a habit
The bottom line
Refresh your calories about every five kilos you lose. Or every four to six weeks, whichever comes first. The reason is honest maths. A smaller body burns less, about 50 calories a day less for every five kilos. Type your new weight into Burnie, get a fresh number, and the scale keeps moving. Do not refresh every day. That is just chasing water.