Mood Changes in Caloric Intakes

“Jumping into a 40% energy deficit may result in MOOD disturbances for the first ten or so days, which return to pre-dieting levels by the third week, regardless of the protein-to-carbohydrate ratio. This matches up quite nicely with what many refer to as the “low-carb flu”. The lack of differences between the groups of the current study suggests that perhaps it should be called the “dieting flu,” as it appears that these effects are not isolated to low-carbohydrate diets. 

Similarly, cognition and subjective SLEEP quality showed MINIMAL changes, some of which were transient.

When considered in conjunction with the benefits of HIGHER PROTEIN diets during times of caloric restriction for muscle preservation and satiety, it seems prudent to not worry about the hypothetical problems that a high protein to carbohydrate ratio would have on brain chemistry and neurotransmitters, as these changes do not appear to significantly impact cognitive function. Any mood or cognitive disturbances that do occur appear to be transient and may be owed to the caloric DEFICIT itself rather than the macronutrient ratios” – ERD issue 4 

http://www.sciencedirect.com/science/article/pii/S0031938414006015