Food-related challenges can impact the nutritional status of an autistic individual.  In general, people falling within the autism spectrum of disorders (ASD) have a restricted range of food preferences that predisposes them to poor eating habits.  In a study published in the Journal Pediatrics, Bandini and associates (2010) compared 53 ASD children with 58 typically developing children for dietary choices. Those with ASDs exhibited more food refusal (41.7% vs. 18.9% of foods offered, p < 0.0001), and a more limited food repertoire (19.0 vs. 22.5 foods, p < 0.001). Only four children with ASDs and one typically developing child were reported to demonstrate high frequency single food intake. The authors concluded that the limited food repertoire of ASD children predisposes them to the inadequate intake of a large number of nutrients.

Food selectivity in ASD is usually ascribed to sensory defensiveness. Indeed, the texture or taste of some foods may upset the taste sense much the same way that fluorescent lights may hurt their eyesight.  The problems associated with a selective dietary habit are compounded as food preferences become hardwired routines that are difficult to change.  These routines tend to expand by including behaviors outside the inciting sensory sensitivity.  With time, an autistic person may add other requirements for eating, including: the way the food needs to be arranged in the food plate, how they smell, the temperature of the food, and even the type of dish or cutlery items used at mealtime.  These preferences may prevent a child from trying new foods and restricting particular food types.  New foods, in effect, may precipitate tantrums or other inappropriate mealtime behaviors. In response, parents coax, reprimand, allow the child to take breaks from eating, or cave in and give the child his/her preferred food.  In the majority of instances these actions serve to worsen the behavior of the child (Piazza et al., 2003).

In some cases, routines may serve to organize and orient an autistic individual.  These routines help the individual to better cope with life’s exigencies.  However, in the case of food selectivity, routines can limit nutrition in ways that will vary from patient to patient (Young-Jiang et al. 2017).  This may help explain why the medical literature is lacking in consistent results when evaluating specific nutrients and why patient intervention may need to be tailored to the requirements of each individual.  Indeed, in a recent metaanalysis of the literature children with ASD were found consume less protein (standardized mean difference = -0.27, 95% confidence interval (-0.45, -0.08), calcium (-0.56 (-0.95, -0.16)), phosphorus (-0.23 (-0.41, -0.04)), selenium (-0.29 (-0.44, -0.13)), vitamin D (-0.34 (-0.57, -0.11)), thiamine (-0.17 (-0.29, -0.05)), riboflavin (-0.25 (-0.45, -0.05)) and vitamin B12 (-0.52 (-0.95, -0.09)) and more polyunsaturated fat acid (0.27 (0.11, 0.44)) and vitamin E (0.28 (0.03, 0.54)) than controls (Esteban-Figuerola et al., 2018).  The long-term effects of this food selectivity for an autistic individual are unknown, specially as we consider an aging population and the ripple effect malnutrition may have on comorbidities.  Indeed, for many autistic individuals the combination of an imbalanced diet and a sedentary life may lead to obesity.  This predisposes the autistic individuals to a plethora of chronic diseases including cardiovascular disease, type 2 diabetes, and even some types of cancer.  It is therefore unsurprising, but quite alarming, that there is a high prevalence of  diabetes, hypertension, and obesity within the ASD population (Flygare Wallen, et al., 2018).

It is important that the autistic individual establishes proper eating habits.  There should be three meals per day and some nutritionist recommend 2 scheduled snacks for children. However, eating between scheduled meals should be limited or discouraged.  There should be an attempt to try new foods, albeit in small quantities.  In previous blogs I have emphasized how autistics that only eat processed foods stand at risk for constipation as they lack the proper amounts of fiber in their diets. Even if you try to correct the GI problems by giving fiber, constipation may lead to impaction in those cases where fiber-rich foods or supplements are not given with ample water. I would also emphasize doing exercise while receiving fiber therapy

Those interested in further reading can access:

Exercise and autism

Autism: the usefulness of exercise

Iron and autism

Benefits of a fiber diet for autistic individuals

References

Bandini LG, Anderson SE, Curtin C, Cermak S, Evans EW, Scampi R, Maslin M, Must A. Food selectivity in children with autism spectrum disorders and typically developing children.  J Ped 157(2): 259-264, 2010.

Esteban-Figuerola P, Canals J, Fernandez-Cao JC, Arija Val V. Differences in food consumption and nutritional intake between children with autism spectrum disorders and typically developing children: a meta-analysis. Autism 2018 [Epub ahead of print]

Flygare Wallen E, Ljunggren G, Carlsson AC, Pettersson D, Wandell P. High prevalence of diabetes mellitus, hypertension and obesity among persons with a recorded diagnosis of intellectual disability or autism spectrum disorder. J Intellect Disabil Res 62(4):269-280, 2018.

Piazza CC, Fisher WW, Brown KA, Shore BA, Patel MR, Katz RM, Sevin BM, Gulotta CS, Blakely-Smith A. Functional analysis of inappropriate mealtime behaviors. J Appl Behav Anal 36(2):187-204, 2003.

Young-Jiang L, Jian-Jun O, Ya-Min L, Da-Xiong X. Dietary supplement for Core Symptoms of Autism Spectrum Disorder: Where are We Now and Where Should We Go? Frontiers in Psychiatry 8:155, 2017.