Even the veggies with a very high carb content (potatoes, corn) are low (~15-20%). Bread has about 50%, maccaroni about 35%, while other veggies (broccoli, carrots) usually have less than 10% carbs.

Sorry I am not a doctor and at a superficial level I was thinking of veggies vs bad carbs. Would not go further because what I know, I know, but I am sure it can be challenged and people will do better to read on these.