Increasingly, epidemiological studies are showing the benefits of exclusive breast-feeding to infants in industrialized countries, as they have previously for those in developing countries. In this review we have focused on several recent developments, in particular on the interplay between infant behaviour and maternal physiology in regulating breast milk supply. This will illustrate that many past and current clinical problems concerning breast-feeding are likely to be of iatrogenic origin, the products of imposing arbitrary rules for breast-feeding management. In order for the protective benefits to be fully realized it is necessary to ensure that breast-feeding is free from prescriptive practices. We will illustrate the key role played by the infants' control of appetite in the hope of encouraging clinicians to empower infants to exercise more control over the feeding process.