©2020 by Theresa Regan

Autism and Eating Patterns: What You Need to Know

#autism #adultautism #autismandeating

Photo by Ethan Sexton on Unsplash

There are a few things I ALWAYS ask my patients on the autism spectrum. One of them is "What do you eat?" Eating behaviors can be impacted by many of the non-social criteria of the autism spectrum including rigid and ritualistic behaviors, repetitive behaviors, intense interests, and sensory processing differences.

I'll never forget the time I asked an ASD female with diabetes, "What do you eat?" She quickly answered, "mashed white potatoes." There was a long pause before I realized she was done listing the foods she eats. Here she is, a diabetic who is living off carbs because of eating characteristics related to autism. This was really important for her medical team to understand because she would not be a patient who could take a handout on diabetic nutrition home and substantially change her eating behaviors.


1. Restricted, repetitive eating patterns

Many on the spectrum eat a restricted number of foods over and over again. Sometimes this takes the form of "food jags" where the individual eats a few foods for months or years (peanut butter and potato chip sandwiches) and then switches to something else (e.g., hot dogs with relish) for months or years.

For some of these folks, sensory issues don't seem to play a huge part in the food preferences, but. they are very repetitive in their eating patterns.

2. Sensory Processing Variants

a. Over-sensitive and Picky eating patterns: This is the case for the ASD individual who is very aware of the slightest difference in the food in front of her. It may be "her favorite" food, but tonight it is "too crunchy, too brown, or too wet." She may be able to tell the difference between the same foods but in different brands (e.g., various brands of basic, thin cut potato chips). There may be only 4-5 items that the individual will tolerate to eat because of sensory sensitivities, often associated with the texture of foods rather than taste. Some individuals with sensory sensitivities will eat a variety of food, but it must all be separate. There is, in those cases, an intolerance of the mixing of textures.

b. Under-reactive and Adventurous eating patterns: Some in the spectrum show very significant under-reactivity to certain sensations such as pain or noise. In the case of eating, they may be significantly under-reactive to the texture, seasoning, and temperature of the food. This is the person who "eats anything." This pattern may also represent a sensory processing deficit.

c. Interoceptive Cues: Those with interoceptive sensory processing deficits (an awareness of physical states) may show over-eating or under-eating associated with a poor understanding of their level of hunger or thirst. Some of my patients are regularly hospitalized for dehydration and related urinary tract infections or fainting. Some are admitted for concerns of severe malnutrition. Alternatively, some seem to not know when they are full, and will gorge themselves with food without feeling satisfied. Hoarding of food can also be seen in the spectrum.

3. Ritualistic/Rigid Eating Patterns

Some individuals on the spectrum eat a fairly good range of food, but have significant rituals or rigid patterns of approaching the meal. For some, this means a rigidity about whether more than one food is on the plate at a time, what order the foods are eaten in, whether the foods are touching, and what foods are served together (e.g., grilled cheese MUST always be accompanied by tomato soup).

4. Intense Interests

For some on the autism spectrum, their special interest has to do with nutrition, weight, and/or exercise. This person may keep copious notes about calories, food groups, time and location of exercise, etc. For many, there is not a concern about weight per se, but when they dive into an interest, they are "all-in." For others, the rigid and ritualistic behaviors combine with intense interest and does include an impact on weight or an excessive monitoring of weight such that an eating disorder is appropriate.



In cases of an autism spectrum related eating problem, it will not be effective to explain to the person why they should change and then send them home with educational handouts. Their's is a neurologic eating pattern and cannot be significantly altered in the long term by repeating educational material about what the person "should eat" instead.


Team up with the individual to see if the person can tolerate something with more nutrition. Move slowly, introducing one new item at a time. For example, the woman who only ate mashed white potatoes could also tolerate nutritional shakes/drinks. The addition of this element helped her get protein, vitamins, minerals, and fiber.


Medical team should understand that nutritional monitoring will be important. For example, physicians may wish to check albumin levels (protein), as well as vitamins, etc. Some nutritional deficits can become so severe, they result in permanent brain damage (e.g., deficits in thiamine can lead to a Korsakoff's Syndrome). Nutrition supplements in some form may be important to prevent these problems.