Answer to Q24.
An Infant feeding pressure group has claimed on a television release that "infant formulas are full of sugar" and hence are contributing to obesity. This statement is totally incorrect. All the regular infant formulas contain the same sugar (lactose) at the same concentration as in human milk. Soy formulas do not contain lactose although the sugar level is the same. Lactose is present in human milk at rather higher levels [ around 7%] than cow's milk, and it is considered a very important source of readily available calories for the baby. Just why milk contains lactose, a sugar which exists almost nowhere else in nature, in uncertain, although it may be related to the use of the galactose part of lactose in making certain complex sugars in the brain and other tissues. But we know that babies can make galactose themselves from glucose. Lactose also has a role in aiding the absorption of calcium and other nutrients.
There have been some studies which have suggested that formula-feeding may be a contributory factor to obesity in later life. Unfortunately this is difficult to determine as the interval between infancy and the development of obesity is usually many years and so many other factors, including socioeconomic, educational and similar factors as well as nutrition, are involved and interact. We do know that overfatness in infancy is little correlated to adult obesity, the relationship strengthens as the child gets older into adolescence.
The recent publication of new infant growth graphs based on breastfed infants may help. Previous widely used graphs were assembled in the USA many years ago when almost all infants in that country were formula-fed. We may as a consequence not only have overestimated the optimum rate of growth of young infants, but also be regulating the composition of infant formula to meet those growth rates. Until there is regulatory change it is not possible to modify the composition of any formula. It is not yet time to make such changes until we have more information.