All and all You have to see for yourself because all babies are different. My hubby and i but love spicy food and i have ate it and baby has not had a problem with that or veggies. But pizza doesn't agree with him.
The big no-no is broccoli. Cruciferous (tree-like) vegetables can cause baby extreme gas and discomfort. Every baby is different though. As your breastfeeding, keep track of what you eat and how baby responded. Keep in mind, baby eats what you eat, but about 2 hours later bc it takes time for your body to process food. So if you had something spicy for lunch and baby is fussy around 4 pm, your baby probably does not like spicy food.
I eat spicy food a lot and haven't had an issue with it.... I did how ever slowly reintroduced spicy foods because I was worried about it too.... I just couldn't deal with how bland some things are without hot sauce.