elmhar

If you think these are causing allergy symptoms of some sort, a 2-week exclusion followed by a "challenge" should be instructive. Do not challenge dairy & soy together.

Dairy can be tricky to remove. Many prepared foods, "boxed dinners," 'non-dairy creamers' and vegetarian cheese substitutes contain caseinate, a dairy ingredient & prime allergen. If you want to do a good job on your elimination & challenge, it pays to read labels carefully.

For other symptoms, like Rheumatoid Arthritis, typically the studies show improvement in a subset of patients (not all benefit, but some do, very much) after 6 weeks on dairy-free diet.

So, in part how long your elimination period should be depends on your symptom type.

Best wishes.