A Very Scientifc Explaination Possibly Describing Why Neurodiverse Children are Often Picky Eaters

I am a huge fan of the neurodiversity movement. This movement empowers people with autism and other differences in behavior that are thought to be related to how the brain works. The movement asks neurotypicals (such as myself) to view people with autism or pervasive development disorder as human beings who simply do things a little differently. These people are not victims, and the current act of glorifying people who do "nice" things for the "poor helpless special kid at school" (see the quarterback who takes the down syndrome girl to the prom because he's like soooo nice) actually have a negative emotional impact on them.

But, I digress. As mentioned before, the brains of the neurodiverse do things a little differently than those of neurotypicals, and we should ALL (neurodiverse included) have an understanding of these differences. Perhaps you have stumbled upon this post because you are neurodiverse and were doing research on why you perceive certain things in certain ways. Maybe you are looking for information on how to deal with sensory overstimulation in order to live more comfortably.  Maybe you’re the parent of a neurodiverse kid who is at their wits end about why their child is so bothered by seemingly insignificant things. Or perhaps, you just really like science and have an interest in learning about the latest data out there, regardless of what category you fall in to.

I wrote this piece using data gathered via metanalysis for a poster session I did in grad school. The topic is a fascinating look in to the human mind. If you are a parent of a neurodiverse kid who is an incredibly picky eater, this topic is very important for you. It is imperative for your child’s health and wellbeing that you understand what is at the root of this “annoying behavior”. The sensory stimuli differences that cause your child to be a picky eater are actually extremely uncomfortable. This behavior is markedly different than a neurotypical child who refuses to eat certain foods because they are “yucky”. You can convince a child who does not have sensory processing child to eat, and eventually enjoy, broccoli. A child with sensory processing disorder who experiences extreme physical discomfort (eg. nausea, physical pain, ect) from eating broccoli cannot be coaxed out of this. Furthermore, to force them to eat broccoli is cruel. It is your job to take all the necessary steps to ensure that your child will not become malnourished. There are plenty of things that you can do to help them eat a balanced diet.

If you an older neurodiverse person who is interested in using therapies to be able to eat a more diverse diet (perhaps because you would like to try new foods, or because you have developed a health ailment related to your diet), I urge you to talk to your doctor and find therapists who are educated in this area. It would be most beneficial to find a doctor or therapist who also has sensory processing disorder, as their personal experience with the condition is worth more than most textbook education on the topic.

Though I am neurotypical, I have sensory processing disorder. That’s why I am so interested in the topic.

DISCLAIMER: I am not a prescribing provider, occupational therapist, or registered dietitian. This information is provided by a graduate student who is not yet allowed to practice. This information is in no way medical advice, and is not intended to diagnose or treat any condition. It is merely for entertainment. If you would like more information on this topic, please seek medical advice from a doctor or midlevel practitioner who can provide you with a diagnosis. 

Introduction

Sensory processing disorder (SPD), formerly sensory integration disorder, is a neurological disorder affecting the perception of sensory stimuli perception.¹ SPD patients may experience overstimulation in certain sensory receptors, as well as under stimulation in other sensory receptors. Furthermore, SPD patients may exhibit crossed sensory paths, such as the nausea and vomiting from hearing certain sounds that should not be expected to cause vomiting. SPD commonly co-occurs with autism spectrum disorder (ASD) and other pervasive development disorders (PDD).²

Thesis

Children diagnosed with SPD are at an increased risk of malnourishment due to malfunctioning sensory input. All children with an ASD or PDD diagnosis should be monitored for SPD signs. Furthermore, all children with an SPD diagnosis should be monitored for signs of poor nutritional status.

Pervasive Development Disorder, Specifically Autism

PDD is a broad diagnosis that includes autism, Asperger’s, Rett’s syndrome, childhood disintegrative disorder, and PDD-not otherwise specified.³ PDD is generally characterized in developmental delay, failure, or regression.

One in sixty-eight US children fall somewhere on the autism spectrum.⁴ ASD is characterized by a regression of normal development between ages 1-3 years old. ASD toddlers may suddenly stop making eye contact or speaking after a period of normal development. The spectrum ranges from “high autism-low functioning” to “low autism-high functioning”. Patients on the “high autism-low functioning” area of the range are generally unable to walk, speak, feed, or clothe themselves. High functioning autistics have relatively few developmental disabilities, and can lead fairly average lives. The hallmark signs of autism are obsessive fixation on a particular topic, avoidance of eye contact, inability to read social cues, and unusual interaction with peers. Young children with autism may prefer to organize toys, rather than act out in an imaginative fashion.⁵ ASD can occur with or without a deficit in intelligence quotient.

The cause of ASD is currently unknown, however, there is thought to be a genetic component.⁶ ASD occurs commonly in siblings, particularly identical twins. An environmental activation of genes is the leading theory on the development of the condition.

Sensory Processing Disorder

SPD is a malfunction of the sensory system. This condition affects both ascending and descending neurological pathways.⁵ SPD is not currently recognized as occurring as a standalone condition, however emerging research is suggesting that SPD can occur in the absence of PDD. 90% of ASD patients experience SPD, and 5-16% of the general population experience SPD.

According to adult self-report data and observational data of children, the overstimulation that results from SPD is extremely uncomfortable.⁷ Simple everyday experiences, such as television viewing or teeth brushing, can be unbearable for SPD patients. As a result, patients will actively avoid stimuli that they know to be unpleasant. Avoidance of unpleasant stimuli is perfectly normal, but becomes a problem when the unpleasant stimuli is hard to avoid.

SPD also involves some degree of understimulation.⁸ In cases of understimulation, it is unclear whether the ascending path way, the cortex, or the descending pathway are responsible for the inappropriate stimuli response. It is also unclear why some stimuli causes overstimulation, while other stimuli goes almost unnoticed.

Sensory Processing Disorder’s Effect on Feeding

SPDs can interfere greatly with mealtimes, as mealtimes are generally filled with stimuli.² There is a wide range of smells and colors in foods. This provides olfactory and optical stimuli. Eating is generally a social activity, this provides auditory stimuli. The texture of foods ranges from soft and mushy to hard and crunchy. Utensils can be cold, metallic, and sharp or they can be plastic and flimsy. This provides both oral tactile stimulation and digital tactile stimulation. Finally, there is a wide array of food flavor combinations. This provides gustatory stimulation.

Patients with ASD may gag or vomit when they attempt to eat certain foods, as a result of inappropriate signaling from the brain that the food should be expelled via emesis. They may feel physical pain from the sound of a fork scraping against a plate. They may feel an indescribable discomfort from having a grape explode in their mouth.

Sensory Processing Disorder, Food Selectivity, and Malnourishment

SPD patients actively seek to avoid eating foods that cause them discomfort. Older children and adults may flat out refuse to eat certain foods and food groups, while younger children throw tantrums and dodge the feeding spoon⁷. Children with ASD are more likely to refuse foods, and have a smaller bank of acceptable foods relative to their non-ASD peers.⁹

Omission of foods and refusal to eat put SPD patients at risk for malnourishment.¹⁰ The majority of studied SPD patients consume adequate kilocalories, but favor carbohydrates over lipids and proteins. SPD patients generally demonstrate normal anthropometric values due to acceptable kcal intake. However, they tend to favor refined carbohydrates as their primary source of kcals. A lack of lipid, fat, and plant based carbohydrate intake results in micronutrient deficiencies. Most SPD patients do not consume the recommended daily intake (RDI) levels of vitamins A,D, and K. Their intake also lacks calcium, choline, fiber, magnesium, phosphorous, and potassium. Furthermore, excess consumption of specific foods results in intakes above the upper limit (UL) of copper, retinol (despite low intakes of vitamin A overall),folic acid, zinc, and manganese. Most B vitamin and iron levels are adequate.

Interventions for Sensory Processing Disorder Related Malnourishment

Anthropometric values and blood values for micronutrients should be measured by a prescribing provider during annual checkups.¹⁰ Additionally, the patient should be monitored for signs and symptoms of nutrient deficiencies. Access to a dietitian should be recommended at the first sign of malnourishment. Occupational therapists (OTs) should be utilized from the beginning of the SPD diagnosis. OTs can help the patient learn to effectively cope with overstimulation. They can also provide insight on how to limit stimuli that is not absolutely essential to feeding. Stimulation is compounded by all of the stimuli in the environment, therefore, it is beneficial to limit stimuli during feeding. Dimming lights, reducing noises, and using utensils that the patient does not have a strong reaction to can help them adequately cope with food specific overstimulation. Foods that cause overstimulation can be hidden in foods that the patient does not have difficulty with. This practice can help provide needed nutrients without causing a reaction in the patient. Finally, supplementation via nutritional formulas can be beneficial to the patient. In the rare case that kcal requirements can not being met through interventions, total parenteral nutrition (TPN) and enteral nutrition (EN) can be used.

Conclusion

SPD is a condition that often co-occurs with PDD. SPD is over or under stimulation resulting from environmental stimulation. The condition becomes a problem when it interferes with the life of the patient in a profoundly negative way. SPD affects nutritional status due to the stimuli filled nature of feeding. A multi-disciplinary therapeutic approach can provide relief of SPD symptoms for patients. This team should include prescribing providers, dietitians, and occupational therapists. SPD patients should be monitored for malnutrition and below average anthropometric values.