Well the jury is out on this one.
Sweet Potatoes are low on the glycemic index and contain high amounts of fibre, vitamins (especially beta carotene and vitamin A), minerals and potassium.
Sweet potatoes, like all vegetables grown underground, do contain sugars but the sweet potato releases the sugars slowly, so any effect on blood sugar levels is slow and steady, unlike the white or red potato. But they still affect your blood sugar and some people won’t touch them because any disturbance to blood sugar levels isn’t worth it.
We use them but tend to use them as a treat and not as a staple.
They should be avoided if part of your motivation is weight loss or if you are trying to be in ketosis.