Are you trying to avoid certain foods for weight loss or for thyroid issues.
The cautions listed above are great- but if you are looking to lose a few pounds too then you need to regimate yourself more.
Google the Zone diet or even South Beach and see how you can achieve both weight loss and thyroid balance.
A big No NO is sugar - try to eliminate that totally. We hypo's store sugar so bad. Also in any high carb diet - Carbs turn into sugar so elimination of that too is needed. Raising sugar levels with hypothyroidism can be very damaging to us.
But we crave both these things.
Elimination has to be #1 on our caution list.
Avoiding soy has been a major problem for me since discovering the thyroid problem. I also have Celiac (must avoid gluten as wheat, rye, barley, plus am one of those who needs to avoid oats too) + Dairy Intolerance (no cow's milk products of any kind in foods or medications). Before the thyroid prob was dx'd, I was using soy/tofu as a good source of protein and calcium, besides trying to limit the amount of meat in my diet. (I would love to be able to go on a Vegan Gluten Free Diet as it lowers cholesterol among other healthful benefits. But, I am finding it soooooo hard to totally give up meat - mostly chicken and fish.) Fortunately, I love fruits, vegetables, beans and nuts. It is important to know that that cooked broccoli, cabbage, and brussel sprouts are OK for us thyroid folks if not eaten often or raw...always eat them cooked, it lessens their effect on thyroid medications.
Any "white" starches. Adds to stress, anxiety, etc.