I have zero faith in those machines. I once tested at 12% body fat in the morning and 8% in the evening (dehydration).
Most people who think that are holding water really are “holding fat”.
That having been said… if water retention truely is an issue I recommend:
Trying to lower cortisol (phosphatidylserine around workouts and in the evening, 600-800mgl; 2000mg vitamin C twice a day, rhodiola in the morning)
Decrease your aldosterone and vasopressin hormones (that make you retain water). To do so you have to drink like there is no tomorrow… I’m talking 6-8 liters per day. That might seem counterintuitive but it will prevent water retention by decreasing the hormones that make you retain water, be prepare to visit the bathroom a lot.
Improve digestive system health (fermented foods, probiotics, finding if you have food intolerences, etc.)