Contrary to popular belief, there are no specific foods that must be eaten or completely avoided by a breast-feeding mother. Her varied diet is an advantage for the baby’s long-term development: different foods alter the flavour of breast milk and give the baby a wide range of taste experiences, from birth.1,2 As mother and baby get used to each other’s routines, the mother will identify whether some foods affect her baby’s constitution (for example, causing diarrhoea, colic symptoms or restlessness), and can avoid them or limit their intake as required.
The breast-feeding mother should drink to satisfy her own thirst and remain hydrated; drinking more than is needed will not increase her milk supply.
A moderate intake of caffeine generally does not cause a problem for most breast-fed babies, but excessive caffeine may make the baby fussy and restless.3 Theobromine is in chocolate and cocoa and is similar to caffeine, and may cause similar effects if consumed in large quantities.4 Recreational drugs, alcohol, nicotine and illegal drugs all pass into the breast milk to some degree. Illegal drugs pose significant health hazards to mother and baby.3

 

References1. Maier A et al. Food-related sensory experience from birth through weaning: contrasted patterns in two nearby European regions. Appetite 2007; 49: 429–440.
2. Mennella JA. Experience with a flavor in mother's milk modifies the infant's acceptance of flavored cereal. Dev Psychobiol 1999; 35: 197–203.
3. Liston J. Breastfeeding and the use of recreational drugs – alcohol, caffeine, nicotine and marijuana. Breastfeed Rev 1998; 6: 27–30.
4. Martín I et al. Neonatal withdrawal syndrome after chronic maternal drinking of mate. Ther Drug Monit 2007; 29: 127–129.

From: Journal of Family Health Care Bulletin. Directory of Breast-Feeding Advice. December 2009. Published with JFHC 2009; 19(6). http://www.jfhc.co.uk/images/stories/breastfeeding.pdf