Encouraging vegetable intake in children : the role of parental strategies, cognitive development and properties of food

Background Despite the health benefits, children’s fruit and vegetable intake is below that recommended. This thesis focuses on the role of parental strategies, children’s cognitive development and properties of food in order to develop new approaches to increase fruit and vegetable preferences and intake in 4 to 12-year-old children. Methods First, we conducted a qualitative study (N=28) with three age groups representing different cognitive developmental stages, and a parental survey study (N=242). These studies indicated that texture was more important for 4-5-year-old children’s food preferences than for 11-12-year olds and that the parental strategy of ‘Choice’ was positively related to both children’s fruit and vegetable intake. Subsequently, in three intervention studies, the focus was on vegetables only, because previous approaches have been less effective for vegetable intake than for fruit intake. We investigated three approaches for their effectiveness in increasing children’s vegetable acceptance: 1. Varying the preparation method (4-12y; N=94): Carrots and French beans were prepared in six ways: mashed, boiled, steamed, grilled, stir-fried and deep-fried. 2. Flavour-nutrient learning (7-8y; N=19): During a 14-day learning period, vegetable flavours were combined with energy (maltodextrin) or without energy in a drink. 3. Choice-offering (4-6y; N=303): Children had no choice, a choice before a meal, or a choice during a meal regarding which vegetable out of two they were going to eat. Results Varying the preparation method demonstrated that steamed and boiled were preferred over the other preparations (p<0.05). Positive predictors of vegetable liking were a uniform surface, the typical vegetable taste and crunchiness, whereas brown colouring and a granular texture negatively predicted liking. Due to insufficient consumption of the vegetable drinks (≈3 grams of 150 grams), flavour-nutrient learning could not take place. The pure vegetable taste was too intense. In the choice-offering study, the children appreciated a choice before the meal, but the three conditions did not differ for vegetable liking (p=0.43) or intake (≈52 gram; p=0.54). In the no-choice condition, high reactant children consumed less vegetables than low reactant children (Δ=28 grams; p=0.04). Conclusion To encourage children’s vegetable liking and intake, the following approaches may be most promising: 1) serve vegetables as crunchy as possible without brown colouring or a granular texture; 2) provide children with choice during vegetable eating; 3) stimulate a positive vegetable-eating context. Finally, serving vegetables in mixed dishes is a good way to facilitate flavour-flavour and flavournutrient learning, but the effectiveness of flavour-nutrient learning for increasing children’s vegetable acceptance needs to be determined in future research