Might body fat levels play a role in hunger? My calories & workouts haven’t changed yet it seems like the leaner I get, the hungrier I get. Or is it just my imagination? Is this a leptin thing?
Yes, definitely. Leptin, a chief regulatory hormone tends to fall with dieting and falling body fat levels. Related to this, lower leptin levels impair the functioning of CCK (Cholecystokinin). The relevance of this is that CCK is a hormone that stimulates fullness from a meal. So you can see the implications of the falling body fat – lower leptin – impaired CCK functioning, relationship here.
Then you also have the hormone ghrelin to consider. Ghrelin is a hormone that stimulates hunger. Going back to leptin, there’s a relationship here too. As leptin levels fall, ghrelin levels rise – which means greater hunger signals.
So, that’s a long way of saying that yes, falling body fat levels can be tied to increased hunger signaling.