Food preferences

Children's food preferences strongly influence intake and it is therefore vital to understand how these preferences arise. Psychological research is beginning to reveal the complex interplay of innate, learned and environmental factors which shapes children's eating patterns. Food preferences develop from genetically determined predispositions to like sweet and salty flavours and to dislike bitter and sour tastes. There is evidence for the existence of some innate, automatic mechanism that regulate appetite. In 1–3 years infants energy intake regulation is effective if there is a wide offer of plain foods.

With plain foods, children choose their diet and have a regular growth, without instructions from adults. Beside the theory of self-regulation there is evidence that eating behaviour can be learnt and it is possible to modify energy intake by a repeated offer. Taste acquisition for specific foods is a consequence of learning.

Young children are also predisposed to be neophobic about food. Particularly towards the second year of life, coinciding with an important period of transition to an adult diet, there is a tendency to avoid novel foods (neophobia). Neophobia (literally ‘fear of the new’) manifests itself as a rejection of unfamiliar foods in favour of familiar ones. In a survey of almost 600 2–6-year-old children, neophobia was significantly negatively associated with fruit, vegetable and meat intake⁽Reference Cooke⁸⁾though not with consumption of dairy foods, starchy staples or cakes and biscuits⁽Reference Cooke, Wardle and Gibson⁹⁾.

Food aversions can be learnt in one trial if consumption is followed by discomfort. However, from birth genetic predispositions are modified by experience. There are mechanisms of taste development and positively associated with:

Mere exposure: the more exposure we have to a stimulus, the more we will tend to like it; foods which have been eaten more often tend to be liked more; this is the way that specific preferences grow in different cultures. Several studies suggest that an exposure based approach has promise for improving the quality of children's diets. Particular strengths of the technique are its simplicity and relatively low demands of both parents and children.

Medicine effect: we like better a food that we eat when we are healthy instead of a food proposed when we are ill.

Flavour learning: between 2 foods of different taste, administered one added with sugar and one without, there is preference for the first food also when proposed without sugar.

Flavour nutrient learning: the more a food is energy-rich the more is appreciated, this is a primordial model. Man can recognize the most caloric foods indispensable to life⁽Reference Kissileff¹⁰⁾.

Parental control

A recent paper⁽Reference Birch, Fisher, Markey, Grimm Thomas, Sawyer and Jonhnson⁵⁾ describes two primary aspects of control: restriction, which involves restricting children's access to junk foods and restricting the total amount of food, and pressure, which involves pressuring children to eat healthy foods (usually fruits and vegetables) and pressuring to eat more in general. Parents may use a combination of these methods to obtain a desired result; for example, pressuring a child to eat healthy foods by using bribes or rewards consisting of sugary snacks that are otherwise restricted⁽Reference Sherry, McDivitt and Birch¹⁹⁾.

Parent restriction has short term and long term effect on children's intake. It enhances preference, increases attention and intake at first, then this curb increases intake, increases eating in the absence of hunger, doesn't produce ability to self-regulate diet but causes negative self evaluation, greater weight gain from 5 to 11 years⁽Reference Birch, Fisher, Markey, Grimm Thomas, Sawyer and Jonhnson⁵⁾.

Pressuring children to eat, likewise appears to be counter-productive, reducing children's ability to regulate their energy intake⁽Reference Johnson and Birch⁶⁾. A further study⁽Reference Fisher and Birch¹¹⁾ has linked ‘pressure to eat’ to reduced consumption of fruit and vegetables in 5- year-old girls. A common assumption runs through these studies: that controlling children's intake of food is a causal factor in their poor eating patterns. It is entirely plausible, however, that the direction of causality runs counter to this; that, in fact, parents use of control is a response to unhealthy eating habits. Others researches have explored the impact of controlling food intake by rewarding the consumption of ‘healthy food’ as in ‘if you eat your vegetables I will be pleased with you’. For example, Birch et al. ⁽Reference Birch¹²⁾ gave children food in association with positive adult attention compared with more neutral situations.

This was shown to increase food preference; but as concluded by Birch: “although these practices can induce children to eat more vegetables in the short run, evidence from our research suggests that in the long run parental control attempts may have negative effects on the quality of children's diets by reducing their preferences for those foods.”⁽Reference Birch¹³⁾

Initial evidence indicates that imposition of stringent parental controls can enhance preferences for high-fat and energy-dense foods, limit children's acceptance of a variety of foods and disrupt children's regulation of energy intake by altering children's responsiveness to internal cues of hunger and satiety. This can occur when well-intended but concerned parents assume that children need help in determining what, when, and how much to eat and when parents impose child-feeding practices that provide children with few opportunities for self-control⁽Reference Brown and Ogden¹⁴⁾.

Maternal influences

Mothers are of particular interest on children's eating behaviour, as they have been shown to spend significantly more time than fathers in direct interactions with their children across several familial situations, including mealtimes⁽Reference Mc Hale, Crouter, McGuire and Updegraff¹⁵⁾.

Mothers who exert a greater degree of control over their child's food intake had children who demonstrated less ability to regulate energy intake. External parental control of the child's dietary intake may indirectly foster the development of excess adiposity in the child.

Birch and colleagues⁽Reference Francis, Hofer and Birch^16, Reference Shunk and Birch¹⁷⁾ point out that mothers, who were preoccupied with their own weight and eating, reported higher levels of restricting daughters' intake, encouraging daughters to lose weight over time. In this study, mothers' encouragement of daughters' weight loss was linked to daughters' restrained eating behaviour. This relationship was partially mediated by daughters' perception of maternal pressure to lose weight. These findings suggest that mothers' preoccupation with weight and eating, via attempts to influence daughters' weight and eating, may place daughters at risk for developing problematic eating behaviours.

The predictors of maternal child-feeding style are maternal and child characteristics. Birch and colleagues⁽Reference Birch, Fisher, Markey, Grimm Thomas, Sawyer and Jonhnson⁵⁾ affirm that mothers reported using more restrictive feeding practices when they perceived daughters as overweight and reported using more pressure in child feeding when they perceived daughters as underweight.

Mothers' child-feeding practices were related to mothers' own investment in weight and eating related issues, daughters' observable weight status, mothers' perceptions of daughters' weight status, and mothers' concern for their daughter developing a weight problem in the future. This model held for maternal restriction, in that mothers reported greater use of restriction in child feeding when they had greater weight and eating concerns of their own, when daughters were overweight, when they perceived that their daughters were at risk for developing a weight problem, and when they had concerns about daughters' weight⁽Reference Johannsen, Johannsen and Specker¹⁸⁾.