Fitness trackers aren't as accurate as you think they are
If you’re chasing accurate calorie tracking, then obviously fitness trackers aren't the way to go. They are not the standard form of measure in the research community, but they are often used for preliminary studies. Usually due to the low costs associated with their use over, say, doubly labeled water or a metabolic ward study. Keeping people in a controlled environment is very expensive compared to handing them a Fitbit or a step counter.
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