How accurate is the calorie burn figure from a Fitbit Charge HR into MFP?

jtcedinburgh

Hi - I wondered perhaps if some of you might have done some investigation into this type of thing....???

Since buying my Charge HR I've been working closely with MFP, and regularly see 1000+ KCal 'adjustment' coming from the FitBit app*. I think it's getting the running figure correct - for me, ~450KCal for a 30m 5K jog, which adjusts as around 300KCal into MFP (I guess this is the net figure). But the walking seems high - 700KCal adjustment for ~4-5 miles? I'm eating back most of those calories against a 1500KCal daily target, but am still cautious about eating back ALL due to my suspicion that it might be reading high. PS. My diary is open if you want to take a peek.

ta.

* a typical 1000 adjustment day would be something like a 5K run and assorted walks with around 50-75 'flights' of stairs - me being 88Kg and 6' tall.

autumnblade75

I'm inclined to believe your Fitbit is probably right.

I'm 40 and female, and 5'3 at 65kg, and with my MFP settings on sedentary, I routinely see 1000 calories per day worth of adjustment at a similar activity level. If you would like smaller adjustments, you could change your activity setting in MFP to "Active" or "Very Active." If you do that, you may want to enable negative adjustments, for days that are not so active.

haviegirl

Your readings are similar to what my husband (roughly similar size as you; he's heavier and 6'1") gets for similar exercise. And using the numbers from Fitbit and MFP, he's losing weight steadily per his goal. So yeah, pretty accurate. And my Charge HR has been accurate for me, too--steady weight loss using the numbers.

Spliner1969

It's really dependent on the person and their fitness level. Someone with a high fitness level will burn less in those times, someone with a low fitness level and overweight will burn more. Make sure your fitbit is taking into account your current weight, heart rate, height and age, and I'd say it's probably 80-85% accurate. Never eat back all of your exercise calories and you should be fine. I tend to figure my MFP calorie ranges at IIFYM.com and do not add exercise. That way I know what goals I should be at if I sit on my *kitten* all day. Then I add in exercise as I do it with apps. I never allow myself to eat back more than say half (actually now that I'm at maintenance I allow up to 70% of those calories to be eaten back) of the calories and I was able to lose weight at my intended rate.

Look at it this way, if you're adding those calories back into your goals, eating them back, and you're not losing weight.. it's likely the calculations are off. But if you are eating all or some of those calories back and you're losing weight at the desired rate then it's probably pretty accurate. The most accurate, in my opinion, are the estimates based on heart rate. Here's the rub though, I don't believe (this is my opinion only) that Heart Rates measured on the wrist are all that accurate. I'd rather rely on a chest strap, they seem to be dead-on accurate for me. Any monitor worn on the wrist can be affected by movement of your arm and the type of activity you are performing.

jtcedinburgh

Thanks. I am losing weight, but slower than the 1500 net target would suggest. I guess that this implies that the Charge HR is slightly over-calculating burn, but as I rarely eat all of the FB cals I am still losing (~0.5Kg/week rather than the 1Kg as per the target). However, I am feeling much fitter, which can only be a good thing (regardless of weight!)....