Article by Dr Gillian Harris, Consultant Clinical Psychologist, The Children`s Hospital, Birmingham. Dr Harris carries out research into feeding and eating problems at the School of Psychology, University of Birmingham.
Children are not born liking certain foods. They are born with an inbuilt strategy to learn to like the foods that they are given, foods that will be available in their country and place of birth. The way in which children learn these preferences is determined by the interaction of social, cognitive, and developmental factors. This learning strategy has evolved to ensure that children eat foods that are appropriate for them, and avoid eating non-foods that might be poisonous.
The development of food preferences goes through three stages; the first stage is a time of relatively easy acceptance, the second stage is one of rejection based on the way that foods look, the third stage is one of rejection based on what the child thinks
about the food. Toddler eating behaviour is therefore the result of an interaction between these three developmental stages and the eating environment to which the child is exposed.
In the first stage, which occurs in the first year of life, the infant should be exposed to foods that are being eaten by their family. Infants are born with a liking for a sweet taste, but all other taste preferences, sour, salt, bitter, and their combinations, have to be learned1.
The bitter taste is the most difficult taste to get the infant to accept because this taste is usually associated with toxicity. There is also a genetic difference in the extent to which we can taste a bitter food; this starts in childhood, some infants will react more strongly to the bitter taste than others2.
The infant only learns a preference for foods because those are the foods that are given. Wherever the infant is born, whatever foods are available in that culture, the infant can learn to like them3. There is no evidence to suggest that infants prefer bland tasting foods. They might accept rice mixed with milk but that is because they are used to the taste of milk! And they might make funny faces when new stronger tastes are introduced, but they usually get used to these tastes with continued exposure.
The more different tastes that are given during the period of early introduction, the more likely an infant is to try new foods when they are offered4. Therefore, the more home-prepared fruit and vegetables that an infant is offered, then the more fruit and vegetables s/he will eat in later childhood5.
Firstly, infants get used to tastes and later in the first year, they get used to different textures. By the end of the first year, they have learned to recognize the food that they are usually given: the taste, the smell, the texture, and most importantly the way that the food looks6. This first stage of food acceptance is one of learning to like what is available, or made available, by means of exposure.
This stage is completed by the end of the first year. By the end of the second year, children’s food preferences become relatively fixed. They tend not to change their food preferences between the ages of 2 and 8 years7.
How can this part of the process go wrong?
- Instead of giving the foods that they want their children to eat when they are older, parents might restrict their children to a diet of specially prepared baby food and nothing else.
- If parents want their children to eat vegetables for example, when they are older, then they need to start to introduce these in the first year, so that the infant gets used to the taste and the way that they look. If parents leave these foods and try to introduce them into the toddler diet later, then this will be difficult. This will be especially difficult when the food is an unusual colour (few foods that we give to infants are green) and an unusual taste (few foods that we give to children are bitter – and yet some very good vegetables like broccoli are both green and bitter).
- Infants might miss out on the sensitive periods for the introduction of tastes and more solid textures. Different tastes need to be introduced by at least 6 months, or as soon as possible thereafter. Solid finger foods need to be introduced from 7 months, so that the infant experiences different textures in the first year. When introducing the more solid foods, infants are more able to cope with bite and dissolve texture to begin with – lumpy foods that break down in the saliva. They can then gradually progress to more difficult textures that need moving around in the mouth, or chewing.
- Infants that are delayed will have missed out on a period of relatively easy acceptance. The later that solid foods are introduced then, in general, the more difficult it becomes, and the more problems the infant will have in learning the tongue movements necessary to control the food in the mouth8,9.
- Get a good range of tastes in from the introduction of the first foods.
- Encourage parents to introduce a range of different coloured foods.
- Encourage parents to let their children experiment with food of different textures, both to hold and feed themselves with.
- Make sure that parents know infants have to get used to the taste of new foods and may be wary at first.
The second stage begins at around 12 months. At this age, the neophobic response begins (fear of new foods)10. This stage of relative food refusal is thought to have evolutionary benefit: as the child becomes mobile, then they are less likely to put non-foods or poisonous foods in their mouths. The child knows which foods are strange or new because they don’t match the child’s visual image of the foods that they have learned to like. Foods that the child doesn’t recognize will begin to provoke a disgust response, which in some children can be very strong.
The neophobic response strengthens over this period and tends to peak at around 18 months. Parents will observe that children after this age will refuse foods on sight, and reject them without even tasting them. This response again, would be of evolutionary benefit, to aid survival. It is better to reject a food that could possibly be poisonous, on sight, and without tasting it. Those children who tasted new things more readily would have died out quite quickly!
Around about this age, children will reject foods if they are not an exact match for their image of a food that they know. They may also reject foods that they ate before if they are not an exact match to the way they expect them to be. So, biscuits will be rejected if they are broken and chips will be rejected if they are brown at the ends. It might seem that the child is being ‘fussy’, or flexing their ‘no’ muscles, but in fact they are just responding to a cognitive developmental stage. Each child has a group of accepted foods that they recognize and know that they have had before. Anything else is a non-food and will provoke a disgust response.
Of course, children do take new foods after this period, but they rely on slightly different rules to make choices and decisions. Food must be safe if others are eating it, so children will eat new foods if they see other people eat them.
They will copy adults in the first 18 months, and then, after this they increasingly copy the behaviour of other, slightly older, children11.
Children also start to get verbal labels for foods and to make generalizations at this age. That is, they begin to accept food that is slightly different in the way it looks from the food that they originally ate. At 18 months a chocolate biscuit might have to be a chocolate digestive, whereas by 30 months, a chocolate chip cookie will do just as well!
- Encourage parents to eat healthily too!
- Their children will copy their eating patterns, so they need to set a good example.
Remember, each fruit or vegetable has to be introduced one at a time, so parents need to be reassured about this.
A child won’t necessarily like one vegetable because they eat another, or like one presentation of a vegetable (mashed potato) because they eat it in another form (chips).
This article continues, click here for part two.