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.