Children's hard-wired aversion to pure vegetable tastes. A 'failed' flavour-nutrient learning study.

Conditioning is an important mechanism for establishing food preferences. Although the basic principles for conditioning are well-known, less is known about the conditions under which this type of learning takes place. This paper aims to add to the knowledge of the essential conditions for flavour-nutrient learning with vegetable flavours. We describe a study which aimed to investigate whether flavour-nutrient learning is effective in increasing 7-8-year-old children's preference for vegetables. Their preference for, and consumption of, two different vegetable drinks was measured before and after a 14-day-conditioning period, using a within-subject design. Flavour-nutrient learning could not occur, due to insufficient consumption during the conditioning period: 2.4 g (S.D.=5.6) for the high energy (HE) drink and 3.0 g (S.D.=9.3) for the low energy (LE) drink. The high taste intensity may have caused the insufficient consumption. We hypothesize that the pure taste of vegetables in itself is not acceptable. Mixing vegetables with other foods may lead to gradual acceptance of vegetables through flavour-flavour and flavour-nutrient learning. Future flavour-nutrient learning studies with children should use less intense vegetable flavours.