Although a low-carbohydrate diet ( high-protein diet) can be an effective dietary approach for weight loss, its long-term effect on psychological functions, including mood and cognition might be very bad.
Besides being something known, I can feel it personally when dealing with people who changed their balanced diet ( 50% carbs, 25 % protein, 25 % fat) to pure a protein one! They are always stressed and easily tempered 
And this is what happened to me as well! I tried the protein diet for a week and honestly couldn't resist it for more than 5 days! I started to crave for bread and fruits!
And you can see the pre-menstrual carbohydrate cravings, experienced by 70% of women and the usual binging of those who are on high-protein diets for more than 2 weeks.
Carbohydrates make us feel relaxed, focused, and always in a good mood.
Why?? Here is a short mechanism:
After consumption of a carbohydrate-rich meal, the hormone insulin is secreted. Insulin lowers the blood levels of most amino acids (the building blocks of protein), except for tryptophan (a precursor to serotonin).
When there is a larger proportion of tryptophan, it enters the brain at a higher rate, thus boosting serotonin production.
Protein-rich food have been found to prevent serotonin production.
Serotonin, this neurotransmitter, is the one responsible for elevating our mood. That's why, we feel sleepy, relaxed and satisfied after a rich carbohydrate meal.
if you go back to the food guide pyramid, you can see that the base (starch & bread) provides the higher food consumption. So a well balanced and varied diet of 50 % carbohydrates is the best dietary approach to take.
Another benefit of carbohydrates is their impact on wakefulness. High-carbs breakfast for example improves mental acuity, decreases fatigue, and makes you generally feel positive about life 
You need to be energetic, healthy and happy while doing a diet.
The best choices of carbohydrate foods are always those that are high in fiber to prevent constipation.
So go for whole grain breads, bran flakes, whole fruits, brown rice and pasta.
And don't forget to limit fat consumption. Choose the unsaturated fat containing meals rather than fried fatty meals! Fatty foods make you feel tired and cause abdominal discomfort.
And the end, don't go for any type of diet without asking an expert. Each kind of diet is specific for each one depending on the health case.. 
you are the greatest, i will always "eat like mira"
Glad i recently came across this site, will be sure to book mark it so i can come by often.
Heya i am for the first time here. I found this board and I find It really useful & it helped me out much. I hope to give something back and aid others like you helped me.