Weak & shakey feelings can be from low blood sugar...
Delayed food allergies are usually diagnosed via a combination of symptoms and a blood test that looks for IgG (and sometimes IgA) antibodies to foods. Sometimes you can figure out what your delayed allergies are by keeping a food/symptom journal, but not always...it can be very difficult to figure out patterns when the symptoms come on so long after exposure to the triggering food. That's why the blood test can be more helpful. Most Allergists don't believe in delayed food allergies, so you may need to find a Naturopathic or Integrative physician to order these tests for you.
I just had some tests done through Alletess, which looks for IgG, IgA and IgM food antibodies. I was not surprised by the results - I thought it was pretty accurate.
I hope this helps - take care,
Chronic Lyme Disease, Bartonella (clinical dx only), Gluten & Sulfite Sensitivity, Many Food/Inhalant/Medication/Chemical Allergies & Intolerances, Asthma, Gut issues (dysmotility, non-specific inflammation), UCTD ("Secondary Lupus-Like Syndrome"), Osteoporosis, etc.; G-Tube; TPN via PICC (trying again to wean off the TPN).
Meds: IV Cipro, Heparin (to flush PICC line), Singulair, Claritin, Domperidone, Colloidal Silver, probiotics, digestive enzymes, Milk Thistle, Magnesium, homeopathy.