Lia Goltstein
We all know that one person who will not touch their food if there is a more exotic ingredient in it. Some individuals even demand that all salad ingredients are put into separate bowls, so they can decide for themselves what is in it. These individuals are fittingly known as picky eaters. Picky eating is characterised by an unwillingness to eat certain familiar foods or to try new foods, as well as having strong food preferences [1]. But how come some individuals will not even try Brussels sprouts while others are willing to eat larvae?
Picky eating is a common phenomenon in early childhood. Children take a long time to get used to new flavours, which causes a lot of stress to their parents who simply do not know why their child will not try certain foods. British scientists have studied the causes and consequences of picky eating by using data from the Avon Longitudinal Study of Parents and Children (ALSPAC) [1]. This is a large cohort study, charting the health of 14,500 families. They found multiple associated factors, such as suffering from autism, late introduction of lumpy food (> 9 months), parents not eating the same meal as the child and high concern of the mother about the eating behaviour of the child [1].
However, none of these factors are a necessity to be a picky eater. Scientists from the University of Illinois believed that picky eating was not only caused by the child’s upbringing. They collected the saliva of 140 preschoolers for genotyping and let the parents fill in a questionnaire about the food habits of their child. They discovered that at least two genes related to chemosensory perception played a role in children’s picky eating behaviour [2]. Chemosensory is the ability of your taste buds receptors to react to certain chemical stimuli. In other words: differences in chemosensory causes individuals to taste different subtle flavours when eating the same ingredient. This explains why some individuals find rocket salad too bitter to eat and others find it refreshing [2]. Chemosensory receptors, however, are not the only receptors that determine taste. Other factors include smell (which is detected by the olfactory epithelium of the nose), texture (detected by mechanoreceptors and muscle nerves), temperature (detected by thermoreceptors) and whether the food is spicy or minty (detected by chemesthesis) [3].
Luckily, most children will lose their picky eating habits by the time they reach double digits. Unfortunately, there are also some individuals who will maintain this trait. When picky eating has consequences for someone’s health it is called Avoidant/Restrictive Food Intake Disorder (ARFID) [4]. This disorder can be found in the DSM5 under eating disorders [4]. Health consequences include being underweight as well as being overweight and having poor dietary variety, which can lead to constipation and low energy [1]. Most individuals can be cured through extensive cognitive-behavioural therapy, but when the cause is mostly due to genetics, it is more difficult to achieve success [5].
Thus, it is not easily explained what made someone a picky eater. It is most often a combination of multiple factors, both inherited and learned. This also explains why treatment is not successful for everyone. Therefore, do not call your friend fuzzy next time they say their cilantro tastes like soap [6].
[1] Taylor, C et al. Picky/fussy eating in children: Review of definitions, assessment, prevalence and dietary intakes. Appetite. 95:349-59 (2015).
[2] Cole, N et al. Variants in Chemosensory Genes Are Associated with Picky Eating Behavior in Preschool-Age Children. J Nutrigenet Nutrigenomics. 10(3-4):84-92 (2017).
[3] Mouritsen, O et al. The science of taste. Flavour 4:18 (2015).
[4] Fisher, M et al. Characteristics of Avoidant/Restrictive Food Intake Disorder in Children and Adolescents: A “New Disorder” in DSM-5″. Journal of Adolescent Health. 55(1):49–52 (2014).
[5] Nicholls, D et al. “Selective Eating: Symptom, Disorder or Normal Variant.” Clinical Child Psychology and Psychiatry. 6(2):257–270 (2001).
[6] Mauer, L et al. Prevalence of cilantro (Coriandrum sativum) disliking among different ethnocultural groups. Flavour volume 1:8 (2012).