Let’s start with a few givens (i.e. things that are well documented and known):
- Cortisol is the “stress” hormone. It is good in small amounts (getting you up in the morning, running away from lions) and bad in the chronic long term (immune suppression, abdominal “beer belly” obesity).
- Serotonin is the regulator of the six F’s: Fight, Flight, Food, Falling asleep, Feeling good, and… Sex. Too much is bad too little is bad. The same story as cortisol.
- Serotonin is involved in regulating cortisol secretion by the 5-HT(2a/2c) receptors (more serotonin, less cortisol)
Let’s step into the much neglected world of serotonin research on insulin resistance and obesity. When’s the last time you’ve heard in pop culture about serotonin in any other way than depression? Maybe I’m reading the wrong news sites but the interplay here is important, however rarely talked about.Serotonin has a strong entanglement with carbohydrate consumption. Additionally, fast digesting carbohydrates significantly raise blood plasma levels of tryptophan.
This tryptophan is then transported into the brain and is the precursor for serotonin. In a normally functioning system this would cause satiety ( that I'm really full feeling ) as it increases serotonin levels (and lowers cortisol). On a LCHF diet when we reach satiety our leptin receptors release fat to be converted to ketones which are used by the brain and for energy.
It seems serotonin could be a huge mechanism for failure. A disorder in producing serotonin could lead to the over consumption of carbohydrates with little to no satisfaction (but the craving sensation would linger).By removing carbohydrates and replacing the carbohydrates with alternative protein sources and fat we are able to restore normal function.
Fat fasts, calorie restriction and food scarcity, while at first may seem like a good idea for fat loss, does significantly boost cortisol levels and lead the vicious regain of weight once one strays from the path.
Low carb rehabilitates the serotonin system. There seems to have an extremely positive association between low carb diets and better sleep, mood, and memory (functions relating to serotonin). Also because most low carb advocates will stand by the idea of eating until you’re full- there is no starving cortisol mechanism kicking in- thus helping the body recover from cortisol overproduction. This is however conditional to getting sufficient trytophan as early as possible before activity or early morning as satiety is required to get the leptin receptors to release fat .
And that's why breakfast with protein rich in trytophan is so important It’s at least food for thought… 
Moringa is extremely high in trytophan :)