While some exercise trackers (Fitbit, Apple watches, etc.) may be useful for counting steps and tracking the distance you’ve run or walked, they aren’t very accurate at estimating the calories you’ve burned throughout the day or during exercise.
This is because these devices estimate your calorie expenditure mostly based on heart rate, and fail to account for the many other factors that contribute to calorie expenditure. On top of that, they don’t always keep track of your heart rate perfectly—particularly when you’re sweating during exercise. This oversimplified method of estimating calorie expenditure usually overestimates the number of calories you burn each day, and this is why you might not be losing weight despite eating fewer calories than your device says you’re burning!
The true indicator of how many calories you need to lose weight will be your body’s response to the target macros that Avatar recommends! If you’re not losing weight—despite what your exercise tracker tells you—you’re not really eating fewer calories than you’re burning and will need to eat less food! Stick with the system, and it will ultimately pinpoint the exact macros you need based on your response to the recommended targets.