Autism and Metabolic Health

What is autism?

Autism, or autism spectrum disorder (ASD), is a difference in how the brain develops. It affects how a person communicates, relates to others, and experiences the world. It is called a spectrum because it looks different in every person. Some autistic people need a lot of daily support. Others need little or none.

Autism is lifelong. It is not caused by parenting, and research has shown it is not caused by vaccines. Genes play a big part. Many autistic people see autism as part of who they are, not something to be fixed. Autistic people often have real strengths, such as attention to detail, deep focus and honesty. The goal of support is to help each person thrive, not to make them less autistic.

Common signs and experiences

Social communication:

  • finding eye contact uncomfortable or less natural
  • finding it hard to read facial expressions, tone of voice or unwritten social rules
  • talking a lot about favourite topics, or speaking little or not at all
  • taking words literally

Behaviour, interests and senses:

  • repeated movements or sounds, such as hand-flapping or rocking (often called stimming, which can help with calm or focus)
  • liking routines and feeling upset by sudden change
  • very strong, focused interests
  • being more or less sensitive to noise, light, touch, taste or smell

Signs usually show in early childhood, but some people, often girls and women, are not diagnosed until much later. Many autistic people also have other conditions, such as ADHD, anxiety, epilepsy, sleep problems or stomach and bowel problems.

How it's diagnosed

There is no blood test for autism. A team or specialist, such as a developmental paediatrician, psychologist or psychiatrist, watches the person, talks with them and their family, and looks at their development. Children are often screened at routine check-ups. Adults can also be assessed.

Usual support and treatments today

  • Therapies and support. Speech and language therapy, occupational therapy (help with daily skills and sensory needs) and social skills support. Some families use behavioural programmes. Views on these differ, so it's worth asking questions and finding what feels right.
  • Education support. Individual learning plans and changes at school.
  • Medication. There is no medicine for autism itself. Doctors may prescribe medicines for related problems, such as severe irritability, ADHD, anxiety, sleep or seizures.
  • Health care for other conditions. Treating gut, sleep or other health problems can make daily life easier.

Where metabolic health fits in

Metabolism is how the body turns food into energy. Mitochondria are tiny parts inside our cells that make most of that energy. Researchers have found that some autistic people show differences in energy use, mitochondria, folate (a B vitamin) handling or gut bacteria. That's why scientists are testing diets and supplements, which you can read about below. This is emerging research, not established treatment, and it is not a cure.

When to get help

Talk to your doctor if you notice delays in speech, play or social skills, or if you think you or your child might be autistic. Get help quickly if a child loses skills they had before. Autistic people have higher rates of anxiety and depression. If you or someone you know is having thoughts of suicide, call or text 988 in the US, or call 911 in an emergency.

See the studies and clinical trials further down this page.

Sources: Autism Spectrum Disorder (NIMH); Autism fact sheet (World Health Organization). General education only, not medical advice. Read the full disclaimer.

Reading time: about 6 minutes. General education only, not medical advice.

The short version

Autism spectrum disorder (ASD) is a difference in how the brain develops. It affects social communication and behavior, and it looks different in every person.

Some researchers are asking whether how the body makes and uses energy plays a part for some autistic people. They are testing diets and supplements that act on metabolism: ketogenic diets, a vitamin called folinic acid, a compound from broccoli sprouts, and treatments for the gut.

This is early research. None of these is an established treatment for autism, and none is a cure. Autism is not an illness to "fix." The studies below mostly measure things like language, behavior, gut comfort and daily skills, which matter to many families.

What the research shows so far

  • Ketogenic and modified Atkins diets. A few small studies found better scores on autism rating scales after several months on a low-carb, high-fat diet. Not every child improved. These studies were small, and most had no comparison group or blinding, so parents and staff knew who was on the diet.
  • Folinic acid (a form of folate). Some autistic children have antibodies that can block folate from getting into the brain (called folate receptor autoantibodies). In one well-designed trial, children given high-dose folinic acid made bigger gains in verbal communication than children given a placebo (a dummy pill). The gain looked larger in children who had these antibodies. Larger trials are now under way to check this.
  • Sulforaphane (from broccoli sprouts). A first trial in teens and young men found behavior improved on sulforaphane compared with placebo. A later, larger trial in younger children did not find a clear difference on its main measure. So the results are mixed.
  • The gut. Many autistic children have stomach and bowel problems. A small study of "microbiota transfer therapy" (a carefully screened donor stool treatment) found big drops in gut symptoms and some improvement in autism scores, lasting at least two years. It had no placebo group. Placebo-controlled trials are now running.

The big limits: most studies are small (often under 60 children). Many were open-label, meaning everyone knew who got the treatment, so hope and extra attention can affect the results. Most lasted only months. Few results have been repeated by other research teams yet.

Studies you can read for free

Also worth knowing: a 2017 study in Egypt compared a modified Atkins diet, a gluten-free casein-free diet and a normal balanced diet in 45 children aged 3–8. Both special diets did better than the normal diet over 6 months. It is not free to read (PubMed summary).

Clinical trials

These studies are listed on ClinicalTrials.gov. Status was checked in October 2026 and can change. A listing does not mean a treatment works or is safe.

Folinic acid (leucovorin)

  • NCT04060030: leucovorin vs placebo for social and language skills. Recruiting. Ages 2½–5. Phoenix, AZ and Brooklyn, NY.
  • NCT04060017: leucovorin vs placebo for language in young children. Active, not recruiting. Ages 2½–5. Phoenix, AZ and Brooklyn, NY.
  • NCT02839915: folinic acid vs placebo for language impairment. Active, not recruiting. Ages 5–17. US sites including Lexington, MA and Atlanta, GA.
  • NCT07630506: folinic acid vs placebo. Recruiting. Ages 3–10. Singapore.
  • NCT07642661: folinic acid vs placebo. Recruiting. Ages 3–6. Jerusalem, Israel.

Diets

  • NCT07797725: low glycemic index diet vs modified Atkins diet vs gluten-free casein-free diet, added to usual care. Not yet recruiting. Ages 3–8. New Delhi, India.
  • NCT06315465: modified Atkins diet added to usual care. Status listed as unknown (not updated recently). Ages 3–8. New Delhi, India.
  • NCT06309251: ketogenic diet in children with several conditions, including autism. Recruiting. Up to age 18. Pavia and Milan, Italy.

Sulforaphane

  • NCT02677051: sulforaphane vs placebo. Active, not recruiting. Ages 13–30. Piscataway, NJ.

Gut and metabolism

  • NCT04182633: microbiota transfer therapy vs placebo in children with autism and gut problems. Active, not recruiting. Ages 5–17. Tempe, AZ.
  • NCT07381374: fecal microbiota transplant vs sham. Recruiting. Ages 3–16. Shenzhen, China.
  • NCT06514573: butyrate (a gut-made fatty acid) vs placebo in children with autism and gut problems. Recruiting. Ages 3–6. Rome and Naples, Italy.

Search for yourself: go to ClinicalTrials.gov, type "autism" in the condition box and a word like "diet," "ketogenic" or "folinic" in the other terms box. You can filter by "Recruiting" and by location. Talk with your child's doctor before contacting a study.

Safety first

  • Do not start a therapeutic diet in a child without medical supervision. This matters most for ketogenic diets. In studies, children were followed by doctors and dietitians with blood tests.
  • Ketogenic diets can cause side effects, such as constipation, low energy at the start, high cholesterol, kidney stones and slower growth. They can change how some medicines work.
  • Nutrition risks are real. Many autistic children already eat a narrow range of foods. Cutting out food groups can lead to low calcium, vitamin D, fiber, iron or protein, and to weight loss. A dietitian can help check for gaps.
  • Supplements are not risk-free. Doses in studies were set and watched by doctors. Supplements can interact with medicines, and store products vary in what they contain.
  • Don't stop current treatments or therapies because of something you read here.

Disclaimer

This page is for general education only. It is not medical advice, and it is not advice about any one person or child. We are not able to review anyone's situation. Research summaries here may be incomplete or out of date, so please read the original sources. Always talk with your own doctor, pediatrician or other qualified clinician before changing a diet, starting a supplement, or joining a study. Read the full disclaimer.

If you are in crisis in the US, call or text 988. For emergencies, call 911.