Hello everyone. I have an underactive thyroid. Been doing some research to improve my health. Ive read any soya protein food ie Cauldron sausages, Quorn burgers etc is not good for those who have underactive thyroids. Is this true? Can someone shed some light on this. I eat a lot of Cauldron sausages (meat substitute) food as my hubby is vegetarian. Thanks. Sim.