CalDef tracks your calorie deficit in real time, right on your wrist — combining calorie counting with intermittent fasting tracking. Overview card: see calories in, calories burned (from your watch's activity data), your current deficit, and how far you are from your daily target, all on one screen. Logging meals is fast: pick from a 40-slot meal database you edit from your phone (via Garmin Connect app settings), use quick +100/+250/+500 kcal buttons for one-off food, or dial in an exact number by hand. Fasting card: a live timer since your last logged calorie, your fasting window (16:8 or 14:10), and how long until you can eat again. Weekly card: your deficit and calorie history for the last 7 days, so you can see the trend, not just today. Everything stays stored locally on your watch — nothing is sent anywhere. Built for people who already track activity on Garmin and want calorie deficit and fasting tracking in the same place, without needing a phone app.