Just as an afterthought, I don’t really get why people should only do weekly or fortnightly weigh-ins. Daily weigh-ins, at the same time (after waking up, after morning bathroom visit), make the most sense.
It’s pretty easy to get excited or upset about variations in weight. Maybe my 65.8kg weigh-in this morning isn’t going to be close to what I’ll weigh tomorrow: maybe tomorrow I’ll be back up to 67kg. But this is the precise reason why daily weigh-ins are better: with more data, you can average out your weight for the week, rather than relying on one measurement for the week. Maybe on your weigh-in day you’ll be retaining water, or extra dehydrated. But how would you know, if you had no other data from the past few days to compare it to.
I’m not talking about forming an obsession, which is always unhealthy, but just being informed, and understanding that frustratingly, the scale doesn’t always go down despite our logic.