This interesting thread links Leptin with Glutamate, its quite common for people to stall weight loss on ketogenic diets. And those very obese who loose weight tend to have very very low leptin levels after the weight loss.
On a ketogenic diet, gluconeogenesis is most likely massively increased. The liver, at all costs, needs to maintain normoglycemia as hypoglycemia is death very quickly. This would suggest that following a ketogenic diet, the pathway of gluconeogenesis is massively upregulated becuase the liver cannot afford to ever let the 5g of glucose in the blood drop too low.
Obviously, ketones reduce the need for glucose in the brain, but whatever way we swing it, that 5g of blood glucose rules the day. That must be maintained.
Anyway, there is lots of anecdotal evidence that one of the ways to break a fat loss stall on a ketogenic diet is to kind of carb binge for sometime. Such a carb binge will completely refuel liver glycogen and thus down regulate the pathway of gluconeogenesis, perhaps finally allowing glutamate to cause intense leptin secretion from white adipocytes.
With gluconeogenesis so high during a ketogenic diet, my theory is that glutamine is massively and preferentially turned into liver glycogen, instead of being turned into glutamate or reaching white adipocytes where we can crank up leptin.
I intend to experiment with honey and l-glutamine powder mega-dosing over the coming week.