How it works
Unpause turns your fast into grams with a simple, published model. Here’s every step, and what it can’t tell you.
While you sleep: your resting burn divided by 24. While you’re awake: the rest of your daily burn, spread across your waking hours. Both come from your age, sex, height, weight and typical day, using the Mifflin–St Jeor equation.
Right after a meal, about a third of your energy comes from fat. As the sugar stored in your liver runs low, that share rises: about 59% at 12 hours, 74% at 16 and 86% at 24. It’s the shift researchers see in breathing measurements (the respiratory quotient).
Every minute, Unpause multiplies the energy by the fat share and divides by 9 kcal per gram of fat. Add it up, and that’s the number ticking on your screen.
Try it
Drag along the fast.
Example: a 34-year-old woman, 168 cm, 72 kg, on her feet a bit, asleep 11 PM–7 AM. Your numbers use your own profile.
The phases
The phase on your Today screen tells you where you are. The bar is roughly how much of your energy comes from fat as each phase begins.
Your last meal is still being absorbed.
from 32% fat
Insulin is falling; your body starts reaching for stores.
from 35% fat
Glycogen is going down, and fat use is climbing.
from 45% fat
Fat is now your main fuel. This is the good part.
from 59% fat
Mostly fat, steadily. You’ve reached your goal zone.
from 74% fat
A long fast. Keep water and electrolytes up.
from 86% fat
Workouts
Fat during the workout. The extra energy you use, at a fat share that depends on how hard you go. Easy movement runs mostly on fat; hard efforts burn more sugar.
An earlier fat switch. Burning stored sugar pulls the curve forward, so the rest of your fast burns more fat. Unpause shows both as one number on your ring, like “+8 g”.
How hard? Use the talk test: easy, you can chat; moderate, short sentences; hard, you can’t talk.
The fine print
Fat burned isn’t fat lost. It’s what your body uses while you fast. You store some again when you eat. Net fat loss comes from your calorie balance over days. Unpause tracks that separately and sharpens it with your weigh-ins.
Everyone is different. Sleep, stress, training and what you last ate all shift the real numbers. Treat the grams as a guide to what each hour does, not a measurement.
Not medical advice. If you’re pregnant or breastfeeding, under 18, have had an eating disorder, or have diabetes or another condition, talk to a doctor before fasting. Fasting safely →
