Dietary Concerns

Documented food allergies are twice as common in children and adolescents with autism (10%-16%) compared to their neurotypical peers. Due to this prevalence, it’s possible that there are autistic adults with existing food allergies that might not have been diagnosed in their younger years. Autistic adults who have been classified as selective - or picky - eaters might be avoiding food that simply does not make them feel well, whether it a true allergy or a food intolerance.

Food allergy vs food intolerance

Food allergies are a function of the immune system and can be mild or life-threatening; food intolerances take place in the digestive system and can cause significant discomfort. Harvard Health explains the difference and why it matters.

If there are persistent symptom of gastrointestinal distress, it can be helpful to keep a food diary or food log to see if incidents of nausea, vomiting, itching, diarrhea, hives and constipation can be tied to certain kinds of foods.

The Centers for Disease Control has a free, downloadable example of a simple food diary that can help patients record eating habits.

Special diets

In the early 2000s, some families of autistic children experimented with specific diets (gluten-free/casein-free, specific carbohydrate) to help address physical and behavioral issues. Although some positive results were shared, in some cases, these diets caused nutritional deficiencies that may have followed patients into adulthood. As a result of his work with autistic patients with digestive issues, Dr. Tim Buie, a pediatric gastroenterologist at Boston Children’s Hospital, doesn’t recommend a specific diet for autistic persons. Rather, he concurs that tracking and understanding what foods keep someone happy and healthy play a big role in overall GI health for autistic people.

Dr. Buie explains the role of food choices and special diets in autistic patients:

Picky eating

Many autistic adults gravitate toward (or avoid) foods that are a certain color or texture, or they may eat the same foods, day after day, for months or even years. These preferences are not indications of food allergies, especially if there are no symptoms of discomfort. Autistic adults don’t necessarily have to eat a wide variety of foods at every meal to meet their nutritional needs. For caregivers of autistic adults, it is important to support food choices to the extent that it’s possible and practical if they are healthy and they eat a reasonably balanced diet.

Dr. Buie understands the frustration of caregivers who worry about picky eating tendencies:

You get to be picky, just like I get to decide whether I'll eat asparagus or not. You know, I think all of us have particular food preferences where we tend to avoid them. They become a problem when they're impacting nutrition or when they're impacting weight or balance in some way.

Dr. Tim Buie

Children with autism are 40% more likely to be obese as adults. Research has noted this risk but has not established an underlying cause. Genes, family history, cultural background, medication and eating habits may all play a role. An important part of adult health care is discussing nutrition with a PCP as part of managing overall good health. Weight gain or weight loss from over or under eating specific foods will be part of any yearly exam discussion with a PCP (any significant weight gain or loss should always prompt an immediate appointment). Diet and weight gain are important issues to be raised with caregivers and group home providers and staffs to assure that autistic adults have balanced diets and get regular exercise.

Celiac Disease

Celiac disease is an autoimmune condition in which ingesting gluten triggers a complex inflammatory reaction. It is no more common in autistic people than in the general population, but it is now more frequently recognized in all patients. Symptoms of celiac disease include:

• Diarrhea

• Weight loss or inability to gain weight

• An increase in abdominal discomfort

If these symptoms exist or there’s a family history of celiac disease, a gastroenterologist can test for it through a blood test or biopsy.