I tested Garmin’s Energy Expenditure estimates for 4 weeks. Here is what I found:
TL;DR: Garmin’s daily “Calories Burned” was extremely accurate over a 4-week period (0.5% variance).
Detail:
ETA: 6’4” / 53 yo
At the risk of ridicule…
I am objectively obese despite very good health markers and a generally active lifestyle. I did not feel like my diet was to blame and thought maybe Garmin was over-estimating my daily burn. So I did … “science”… I tracked calories, recorded weights, did math, and recorded.
Here is the breakdown:
Diet
Start 332.6 20260907
Day
1 - 2100
2 - 2400
3 - 2300
4 - 2140
5 - 2280
6 - 3100
7 - 2700
Calories consumed: 17020
Garmin 7 day burn: 34986 (4998/day avg)
Deficit per Garmin: 17966
Weight lost if Garmin was accurate: 5.13 lbs
End weight: 329.9 20260914
Weight lost: 2.7 lbs
Net Cal lost: 9450
Actual Calories burned: 26470 (3781/day avg)
Garmin variance: +24%
Week 2
Day
8 - 2200
9 - 2400
10 - 2400
11 - 2700 - higher calorie lunch
12 - 3100 - higher calorie lunch / stress induced
13 - 2200
14 - 3050
Calories consumed: 18050
Garmin 7 day burn: 29886 (4269/day avg)
Deficit per Garmin: 11836
Weight lost if Garmin was accurate: 3.38 lbs
End weight: 326.8 20260921
Weight lost: 3.1 lbs
Net Cal lost: 10850
Actual Calories burned: 28900 (4129/day avg)
Garmin variance: +3%
Week 3
Day
15 - 1870
16 - 2300
17 - 2300
18 - 1865
19 - 2300
20 - 4840
21 - 2000
Calories consumed: 17475
Garmin 7 day burn: 29701 (4243/day avg)
Deficit per Garmin: 12226
Weight lost if Garmin was accurate: 3.49lbs
End weight: 321.4
Weight lost: 5.4
Net Cal lost: 18,900
Actual Calories burned: 36375 (5196 / per day)
Garmin variance: - 22%
Week 4
Day
22 - 2400
23 - 2370
24- 2405
25 - 2499
26 - 2240
27 - 2940
28 - 2550
Calories consumed: 17404
Garmin 7 day burn: 27,836 (3977 / day avg
Deficit per Garmin: 10,432
Weight lost if Garmin was accurate: 2.98 lbs
End weight: 317.8
Weight lost: 3.60
Net Cal lost: 12,600
Actual Calories burned: 30,004 (4286 / day)
Garmin variance: - 7.78%