ecec,
I have been bf Tim for more than 15 months and am still bf. Apart from emotion, I discovered that I could get more milk if I took in a more meal between breakfast and lunch as well as having teatime. I believed that our body needs nutrients and energy to generate milk of high quality.
So, we may need to take in more food so as to have more nutrients and energy (because in winter when it's cold, some of the food may be used for providing warmth ).