The iHealth HS5 scale uses bio-electric impedance analysis (BIA) to measure body fat. This analysis technology is very accurate and easy to use.
However, variations in the hydration level can affect measurements. If your body is dehydrated, you will probably obtain overvalued measurements. On the other hand, if you are too hydrated, you may notice slightly undervalued measurements. Changes in the level of hydration can be caused by diet (food and drink), exercise, alcohol, caffeine, health status (including menstruation).
To obtain the best possible accuracy and repeatability we advice following the following tips:
- Take measurements at least 3 hours after waking (a long night of sleep tends to dehydrate the body)
- Take measurements at least 3 hours after a big meal or after intense exercise.
- Take a measurement once a week at the same time and under similar conditions. Taking measurements more frequently is not useful since your body fat does not change significantly from one day to the next.
We estimate the best time of day to take a measurement is between 6pm and 8pm (before eating and taking a shower or bath).
By following this advice, variations in hydration will be negligible, and you will be better able to see the actual changes in your body fat.
*credit to Sylvain of iHealth Labs EU
https://helpcenter.ihealthlabs.eu/hc/en-gb/articles/115005876425-iHealth-HS5-Why-does-my-body-fat-vary-