How often should I recalculate my TDEE?

Every 10 pounds you lose, or once a month if you log meals and weigh in. Each pound you lose lowers your daily burn by about 10 calories, so after 10 pounds your old target has quietly lost about 100 calories of its deficit. Redo it too after any big change in your steps, like a new job or a new dog.

It’s easy to set a number once and treat it as fixed. But the body you set it for keeps changing. A smaller body costs less to run and less to carry, so the target that took off a pound a week in month one takes off a little less each month after, with nothing changed on your plate.

The simple version

Your calorie target is a budget written for the body you had when you set it. A lighter body spends less, so the same budget leaves a smaller gap every month.

The numbers

• About 10 a pound. NIH scientists built a model of weight change whose rule of thumb is that every 10 calories a day you cut for good takes off about a pound in the end, with half of that gone in the first year. Turned around, each pound lost lowers your burn by about 10 calories a day.
• A small extra dip. In a 2020 study, 71 people with obesity ate 1,000 calories a day for 8 weeks and lost about 30 pounds. Their resting burn was about 90 calories a day below what their new size explained. After four weeks at a steady weight the gap was about 40.

What to do

• Rerun the calories to lose calculator every 10 pounds.
• Better, measure it: four weeks of meals and morning weigh-ins on the real TDEE calculator give the number your body runs on now.
• In Gyroscope, your meals and weigh-ins feed your energy balance, your weight trend gives a calorie-burn estimate, and your TDEE gets its own trend. See tracking it in Gyroscope.