The role of food experiences during early childhood in food pleasure learning.

Infants are born equipped to ingest nutrients, but have to learn what to eat. This must occur early, because the mode of feeding evolves dramatically, from "tube" feeding in utero to eating family foods. Eating habits established during early years contribute to the development of subsequent eating habits. Therefore, it is fundamental to understand the most important early periods (between birth and 2 years, i.e. onset of food neophobia) for the development of eating habits and the drivers of this development. The role of pleasure in eating is central, especially during childhood when cognitive drivers of food choices may be less prominent than later in life. It is not easy to define and measure pleasure of eating in early childhood. However, it is possible to identify the characteristics of the eating experience which contribute to drive infant's eating and to shape preferences (food sensory properties; food rewarding properties; social context of eating). The learning processes involve repeated exposure (including to a variety of flavours), association with post-absorptive consequences and with contextual signals (including family members). The important early periods for learning food pleasure start being well identified. Beyond the first flavour discoveries during the prenatal and lactation periods (through the infant's exposure to flavours from foods of the mother's diet), the most important phase may be the beginning of complementary feeding. Infants discover the sensory (texture, taste and flavour) and nutritional properties (energy density) of the foods that will ultimately compose their adult diet; parents are still in charge of providing appropriate foods, timing, context for eating. Inter-individual differences in food pleasure learning, related to temperamental dimensions, or to sensory sensitivity also have to be taken into account.