You can also get very bad headaches in reaction to foods that you are sensitive to, or have difficulty digesting. ( eg: oranges/citrus, eggs, dairy, wheat, pork, sulphur in products, monosodium glutamate, the onion family esp leeks, chocolate, carbonised/highly grilled foods, soya, high fat content, etc, quite often just the things you think you love and eat every day aswell! ) And people on the spectrum have a higher incidence of food allergies than the general population.
Anxiety can be the trigger but it is often the daily consumption of something(s) which your body has trouble dealing with which pushes your body's "stress burden" so high in first place.
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