I happened to be thumbing through Lawrence -  Breastfeeding:  A Guide
for the Medial Profession - after my last post and came across info for
managing obesity in breastfed infants (4th edition, p. 384).  Her
recommendations are generally to be aware of feeding for hunger v.
feeding for comforting other needs, have lots of closeness with infant
outside of feeding times, exclusive breastfeeding for 4 - 6 mo.,
encourage infant movement.  And, if excess growth continues, check
milk for high fat content.

Debi Barr