You know, I don't know of any info out there about growth spurts. But I do feel your pain. When very new mine all nursed about every half hour or 20 minutes to get my supply established. There were times when I had to hand the baby off to Daddy just so I wouldn't scream! Of course I am probably certifiable because I am nursing both my 14-month-old and my almost-3-year-old (yay child led weaning!

). What I would do in your situation is eat when I am hungry, but keep a
very close eye on my portions (not doing this is why I'm sitting at about 200lbs right now; I have learned my lesson!). Eat to need, don't worry about hitting an exact number of extra calories. I EBF'ed Linda until almost 8 months, and I think Esther was about 7 mos or so before she really had any interest in food. I don't think most of the info out there accounts for stuff like growth spurts and older nurslings.