What is the association between insomnia and trouble losing weight?

We don't yet know. The two are significantly correlated but we don't yet know how this works. The mechanism linking short sleep periods with weight gain is possibly related to leptin and ghrelin, the two key opposing hormones involved in appetite regulation.
Snooze to lose!! If you are trying to lose weight make sure that you are getting adequate sleep. Sleep deprivation can lead to increase of stress hormones that can make you fat and gain weight. Studies also shows that lack of sleep can causes increase in appetite.