Number 1, Track It!
Can one control anything not quantified? I do not think so.
Personally, i weight every single am using a scale with 0.1 lb resolution; first thing after out of bed, after using the commode and with nothing on & write it down. This strategy reduces confusion & the 0.1 lb resolution typically makes it easy to see the results of whatever i did & ate (mostly ate) the previous day, before i forget.