It's not just the lack of sleep that makes you hungrier and lowers your leptin hormone; it's actually the stress your body feels from losing sleep that causes these changes. This means managing stress might be more important for weight control than just focusing on sleep duration alone.

Our current analysis shows that the evidence we have reviewed leans toward stress being the key factor behind hunger and lower leptin levels after poor sleep, rather than the lack of sleep itself. What we have found so far suggests that the physical strain your body feels from losing rest may be the real link to these changes. We analyzed the available research and found that 46 studies support, 0 studies refute the idea that sleep-related stress plays a larger role than simple sleep loss. Leptin is a hormone that signals fullness to your brain, and our review indicates that the stress response to tiredness may be more closely tied to appetite changes than the hours of sleep you miss. The evidence we have reviewed leans toward the view that managing this stress could matter more for weight control than just tracking bedtime hours. We want to be clear that this is a partial view that improves over time. Not every study looks at the same factors, and our current analysis is based on the data available to us right now. The evidence we have reviewed leans toward stress being the key link, but we continue to monitor new findings as they come in [1]. For everyday life, this means that when you are not getting enough rest, focusing on calming your nervous system might help you manage your appetite better. Simple stress reduction habits, like taking short walks, practicing slow breathing, or setting aside quiet time each day, could be useful steps while you work on improving your sleep routine.