Trust me, you are NOT alone in this.
For me, it's water, because my water drinking is based around my work schedule, which obviously is completely thrown off on weekends!!
I agree that it COULD being slowing progression for anybody since it's almost a third of your week (two days).
My first thought would be, what about setting a SPECIFIC time, just once on Saturday and once on Sunday, to record everything?
Hope this helps!! Good for you on catching a problem area and reaching out to help resolve it!!!
| Pounds lost: 2.5