Preventing obesity.

Editor—Crawford in his editorial on population strategies to prevent obesity has not mentioned an important factor in the aetiology of obesity: the method by which infants are fed. Von Kries et al found that a history of three to five months of exclusive breast feeding was associated with a 35% reduction in obesity at the age of 5 to 6 years, which was not accounted for by social factors, lifestyle, etc. They discuss the evidence for a programming effect of breast feeding in preventing obesity and being overweight in later life. Gilman et al found that infants who were fed breast milk more than infant formula milk, or who were breast fed for longer periods, had a lower risk of being overweight during older childhood and adolescence. These results are consistent with those of the DARLING study, which showed that infants who received no milk other than breast milk in the first 12 months were lighter than formula fed infants, though of similar length and head circumference. This study also found that energy intake of breastfed infants was lower than that of formula fed infants, even after the introduction of solids; the authors say that comparatively low energy intakes are a function of self regulation in breastfed infants. Breastfeeding mothers also lose weight after pregnancy more effectively than those who feed artificially, an advantage seen over at least the first 12 months of breast feeding. Vigorous marketing of junk food is often implicated in the obesity epidemic. What about inappropriate marketing of infant formula milk? In the United Kingdom, with its limited legal restraints, manufacturers can and do actively promote infant feeding bottles, teats, and follow-on formula milk to the public in contravention of the international code of marketing of breast milk substitutes. This recently drew comment from the UN Committee on the Convention on the Rights of the Child. In its observations of 4 October 2002 the committee recommended that the United Kingdom takes all appropriate measures to promote breast feeding and adopt the international code of marketing of breast milk substitutes in light of its low rates of breast feeding. Measures to promote and support breast feeding, including legislation and promotion of artificial feeding, seem to be a rational approach to preventing obesity.