3 Connections Between Autism, Diet, and Behavior

Autism is not caused by malnutrition or food-related challenges, but, for many people, there is a connection between autism and food. Research suggests that food-related challenges have a significant impact on many people who are diagnosed on the autism spectrum.

Father feeding little girl outside
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According to one study, "children with ASD exhibited more food refusal than typically developing children (41.7% vs. 18.9% of foods offered)." Another study concurs: "... children with autism have significantly more feeding problems and eat a significantly narrower range of foods than children without autism." This means that, if you have a child on the spectrum who eats poorly, you're not alone. Poor eating habits can lead to a wide range of nutritional problems which, in turn, can lead to problems ranging from health issues to attentional and behavioral problems.

"Poor eating habits" and "feeding issues" have several different causes and many levels of severity.

Resolving problems with feeding, picky eating, food intolerances, and nutritional deficits can have a positive impact on your child's life. Here are some of the ways in which feeding issues can impact your child, along with some suggestions for addressing the problem.

Feeding Issues Related to Sensory Challenges

Maybe your child won't eat broccoli, apples, nuts, or breakfast cereals. Or won't touch yogurt, milk, applesauce, soup, or oatmeal. In both of these cases, there's a pattern: in the first case, the child is rejecting crunchy foods. In the second case, they won't tolerate smooth or gooey foods.

People living with autism can be prone to sensory overload and sensory defensive, meaning they are easily upset by certain sensory experiences, and thus avoid them. They may hate bright lights or loud noise. They may also avoid strong smells and certain tactile experiences. Certain foods have strong smells and tastes; others have specific textures that may be appealing or disgusting to individual children.

Strategies You Can Try

There are a few simple fixes for eating problems related to sensory challenges:

  • Once you detect a pattern (averse to crunchy, for example), stop serving crunchy food. It's that easy. Cook the broccoli till it's mushy. Serve oatmeal instead of Rice Krispies. There's always a perfectly acceptable nutritional alternative to foods of any given texture, smell, or taste.
  • If you're determined that your child MUST eat certain types of food they can't easily tolerate, consider "hiding" them in other foods. Many parents put veggies into baked bread and muffins, for example.
  • As you're finding ways to accommodate your child's needs, consider finding a sensory integration therapist who has experience with feeding issues. They may be able to help you and your child learn to incorporate a wider range of foods.

Feeding Issues Related to Gastrointestinal Problems

According to a review of multiple studies, there is "a strong relationship and significant correlation between eating problems and gastrointestinal (GI) dysfunction [in children with autism]." This may mean that some of your child's more extreme behaviors may be related to pain and discomfort from gas, bloating, diarrhea, or acid reflux. Solve the underlying problem, relieve the pain, and your child may find it much easier to focus, think well, control emotions, and behave more appropriately.

Signs of GI discomfort can include diarrhea, constipation, flatulence, or a hard belly. You may also notice your child pressing their stomach up against pillows or chairs to relieve pressure.

If your child is verbal and can describe their physical sensations, they might tell you when they are experiencing GI issues, or they may be able to describe their sensations if you ask.

Strategies You Can Try

If you think your child could be experiencing GI problems, you can take some important steps:

  • Start by contacting your pediatrician and asking for a GI evaluation.
  • While you wait for your child's appointment, start a journal to track your child's experience. When do the GI symptoms seem to start (after meals? between meals? at night?)? Which foods seem to trigger the symptoms? What behaviors do you believe are being triggered by GI pain or discomfort?

Milk, Dairy, or Gluten Sensitivity

Some children who have autism seem to have negative reactions to milk or dairy products (associated with lactose or a protein called casein) and/or wheat products (gluten). These reactions may or may not be allergies.

If you believe your child is responding negatively to either milk or gluten, you can consider starting a gluten and/or casein-free diet. It is very important, though, to ensure your child is getting enough nutrition—work with your pediatrician or with a dietician to plan a well-rounded diet.

Feeding Issues Related to Autistic Behavior Patterns

Like many children, kids living with autism would usually prefer chicken nuggets and pizza to salads and fruit. Kids who have autism can get absolutely stuck on very few food choices and absolutely refuse to make even the slightest change.

While it is possible that these preferences have sensory or GI causes, it's also possible that your child has developed a routine that is extremely difficult to change. People with autism, in general, prefer sameness and function well with routines. But sometimes that can get in the way of proper nutrition.

If you're struggling with an autistic child's need to eat the same things, in the same order, day in and day out, start by checking to see if there is a real nutritional problem. If your child eats a limited but complete diet (only 2 or 3 proteins, carbohydrates, and fats) they might not be in any nutritional trouble. If you're worried, you might just supplement their diet with a multi-vitamin.

Strategies You Can Try

If your child's diet is really poor, and you've already addressed any sensory or physical issues, you'll need to address the behavior.

There are several approaches you can take, and you can mix and match:

  • Use a behavioral approach: When you tell your child "eat a bite of spinach and I'll give you a prize," you may solve your child's eating problem. Rewards can work well, but this approach can backfire if it's taken too far. For example, don't offer a toy for every bite of new food, because this will make your child dependent on prompts and rewards.
  • Find foods that are similar to their favorites: If your child loves chicken nuggets, chances are good they'll also enjoy chicken patties (a different shape). They may also be willing to try fish sticks (same shape and texture) or chicken fried steak. Similarly, a child who likes applesauce may be willing to try apple slices or apple pie.
  • Offer options: For some children with and without autism, food is one of the few areas where they feel they can exert control. Rather than getting into a power struggle, offer your child several food options and let them pick those they prefer. Some parents use muffin tins to offer a smorgasbord of small acceptable possibilities.
  • Write a social story: Social stories are short stories, sometimes with illustrations, that you can write specifically to prepare your child for something new. You might write, for example, "When it's dinner time, I sit at the table. There are different foods on my plate. I must eat one bite of every food."
  • Make healthy swaps: A whole wheat version of a favorite snack can up its nutritional value, often without your child having to make a noticeable adjustment.

Resources and Research

A great deal of research has gone into the issue of autism and nutrition. Some findings are helpful in guiding families and doctors.

It's important to note, however, that not all research is of equal quality, and some studies are conducted with a specific agenda in mind. For example, researchers may conduct studies in order to validate a product they want to sell or to convince parents that a particular perspective is correct.

Solid, replicated research studies have shown that:

  • Children with autism have more eating issues than other children.
  • Children with autism have more GI problems than other children. The reason for this has not yet been determined, though there are several theories.
  • Some children with autism are sensitive to specific foods such as casein, gluten, artificial sweeteners, and dyes (this is true of children without autism as well).
  • Some children with autism, probably because of picky eating habits, have nutritional deficits that can be alleviated through supplements.
  • Some problematic behaviors are almost certainly increased by food/nutrition-related issues and can be alleviated through a variety of means, including dietary changes and supplements.
  • There is an increased risk of eating disorders, such as anorexia and bulimia, among people who have autism.

According to current knowledge, autism has not been shown to be caused by particular foods, and it can't be cured through nutritional changes of any kind.

Screening for Feeding Issues

Nicole Withrow and Jennifer Franck developed a screening tool called the Sensory, Aberrant Mealtime Behavior Inventory for Eating (SAMIE), which they applied through a survey to a large group of children and teens with autism. The tool helps parents and practitioners zero in on the specific challenges they need to address and provides some direction for action.

6 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. Schreck KA, Williams K, Smith AF. A comparison of eating behaviors between children with and without autism. J Autism Dev Disord. 2004;34(4):433-8. doi:10.1023/b:jadd.0000037419.78531.86

  3. Karling P, Maripuu M, Wikgren M, Adolfsson R, Norrback KF. Association between gastrointestinal symptoms and affectivity in patients with bipolar disorder. World J Gastroenterol. 2016;22(38):8540-8548. doi:10.3748/wjg.v22.i38.8540

  4. Kinnaird E, Norton C, Pimblett C, Stewart C, Tchanturia K. Eating as an autistic adult: An exploratory qualitative study. PLoS ONE. 2019;14(8):e0221937. doi:10.1371/journal.pone.0221937

  5. Sharp WG, Berry RC, Mccracken C, et al. Feeding problems and nutrient intake in children with autism spectrum disorders: a meta-analysis and comprehensive review of the literature. J Autism Dev Disord. 2013;43(9):2159-73. doi:10.1007/s10803-013-1771-5

  6. Withrow, N. and Alvidrez, L. (2019), "The development of the Sensory Processing, Aberrant Mealtime Behavior, Motor Inventory for Eating (SAMIE) in children with an ASD", Advances in Autism, Vol. 5 No. 4, pp. 268-281. doi:10.1108/AIA-08-2018-0025

Additional Reading

By Lisa Jo Rudy
Lisa Jo Rudy, MDiv, is a writer, advocate, author, and consultant specializing in the field of autism.