calories left to eat for the day

[Plogan22]

Does the number of calories left to eat for the day mean I can eat them and still loose weight? 

[Dominique]

The consensus here seems to be it’s better not to eat back the calories you have left for the day. The uneaten calories will be your safety margin if it turns out Fitbit’s estimate of the calories you burned are on the high side (which is not uncommon).

[rachiti]

Fitbit does a "generic" calorie estimate.  After you've used the device for a couple of months, you will know how much you can eat calorie-wise and still have a good chance of seeing a reduction in fat for you personally.  Additionally, keep in mind that if you're starting an exercise program at the same time - you will increase your muscle mass which can offset your weight loss in fat...but it's still a much healthier weight overall even if it doesn't budge at first. 

In my case, for example, according to Fitibit I could eat 4000-5000 calories per day (not including the 1000 calories per day I had it set to hide) and lose 5 pounds per week.  In reality, I had to eat less than 2,500 calories per day in order to lose 1-2 pounds per week.  Right now I'm eating under 3000 calories per day even though it still has my calories set about 1000 calories per day higher...and I've gained 10 pounds in the last year.  Everyone's metabolism is different.

[WavyDavey]

Besides the good advice from @Dominique about keeping a calorie reserve, I found one other disadvantage to trying to end at 0 calories by midnight. Food eaten after dinner didn't digest well for me.