happy_face wrote:I just "interrupted" the diet because of overwhelming cheese cravings and eating (1 big cheese per day for the last 5 days!

) This is mostly due to PMS. The weird thing is that I didn't crave sugar like I used to
Thats the addiction to opioid peptides. One is particularly perceptive to these 'rewarding' substances during your period, as cholesterol (indirect seronin activator) gets drained from your body (the pre-placenta).
I read that taking more yolks in the second part of the cycle can be very helpful, so I will try that next time. However, I am concerned about the negative impact this might have on acne.
No impact.
Cheese does have a big impact though.
is the serotonin level (lower) the main cause of creating the cravings and other PMS symptoms?
Yes.
If yes, are there nutrients other than yolks that could help maintain the level of serotonin?
To a much lesser degree yes. Vitamin B3 (fish, granadilla, dried fruits) competes with serotonin for their shared precursor; tryptophan.
Tuna is better than salmon, as salmon contains relatively little tryptophan.