Body Composition Analyzers are completely different devices than traditional weighing scales because they measure and calculate what material is in your body, not just how much your body weighs. 

To get the most accurate and meaningful results it is important to measure under as similar circumstances as possible. In the attachment of this article you will find useful tips on how and when to measure to get the best and most consistent results (in English, German, French and Dutch).

Here you can read more about why your measurement results change or fluctuate: Why do my measurement results fluctuate / change?