Weight changes doesn't seem to align with my Fitbit stats

[Calvinkong]

Hi, i'm new to Fitbit and just recently gotten a Charge 3. Before this, i just tracking my calories in/out and macros based on established generic formulas on the web.

I'm in the 3th week of my Fitibit tracking now and what i observed is...

1. My daily calories expenditure kind of too high from my expectation. Fitbit says my daily calories expenditure average around 2.7k~. I have a typical office job and spent about 1hr in gym daily. My BMR is 1.5k~ and after factor in sedentary lifestyle (x1.2), my expenditure sit around 1.8k~ before factor in gym time. 1hr gym time should only equate to 400 calories at most if not lesser... hence before fitbit i always thought my total daily expenditure is around 2.2k only. 

2. All these while I have been eating around 1.9 - 2.1k calories per day because i was basing on the 2.2k calories benchmark, and still eating the same after i gotten fitbit.

3. So i setup a Food Plan in fitbit for fun, and set a goal to lose 2kg with a 250 deficit speed, and fitbit projected i will reach my goal in 7 weeks. Since i still eat 2k~ calories daily.. fitbit reported i'm under budget every day by a huge margin even after factor in the planned 250 cal deficit. But my weight has been hovering the same after 3 weeks.

4. I can only conclude that is either fitbit over estimate my cal out, or i under estimate my cal in. I have been tracking my food intake for a good 1yr now so my accuracy shouldn't be way off. Half of my food is self prepared where i measured everything using digital scales. The other half is outside food which is hard to know for sure... but overtime i have figure out to estimate it against my own cooking and i always factor in extra 10g of fat and 10g of sugar in outside meal for compensation.  

At this point, i really don't know which method i should trust now.. or just go back to the good old fashion.. gut feelings and self inspect in front of a mirror... lol...

[Dominique]

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@Calvinkong wrote:

I can only conclude that is either fitbit over estimate my cal out, or i under estimate my cal in.

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It’s a reasonable conclusion IMO: there’s a margin of error in both. Estimating energy expenditure with a fitness tracker isn’t exact science. Even if your calories out are off, they’re likely to be consistently so. Therefore your Fitbit is still useful as a way to gauge your overall activity, and adjust your intake accordingly.

[SunsetRunner]

There’s a little more to it than just calories. Calories are a factor but your hormones actually determine where those calories go. The hormone that has the biggest impact on the general population is insulin. If you are trying to lose fat then you would want to minimize that insulin spike. If you are trying to gain muscle, then you want the insulin spike. The calorie calculators are just estimates. The only way to know for sure is to try it for a while and see what happens, but if you know for sure you are in a calorie deficit and still, aren’t losing fat, chances are it’s what you’re eating. Eat based on what your goal is. It’s okay to eat out every now and then but if half of your food is fast food or eating at restaurants, you don’t have a good baseline of how much you are actually eating or the content of your food. In the United States, legally, nutrition labels are allowed to be off by I think it’s something like 10%. I don’t know if that also applies to restaurants, but considering portion sizes are not exactly the same when going to restaurants, can you imagine how much you would be off? 

[JimC_99]

I have been tracking calories for close to a year and I find that the Fitbit over-estimates my calorie burn at over 35%.  My weight loss seems to track better with the NIH Body Planner on the NIH website.  Each person will lose weight differently, so find a system that you can use and be patient.