Poblano peppers are low in calories and fat, low carb, and are a good source of fiber, Vitamins A and B-6, iron, and potassium. One poblano pepper includes: 48 calories 1.4 grams of fat 9 grams carbohydrates 3.7 grams of fiber 410 mg of potassium 69% Vitamin A 30% Vitamin B-6