Sweet potatoes are a type of complex carbohydrate. Complex carbohydrates are typically recommended over simple carbohydrates due to the fact that they break down to sugar slowly in the body, providing you with a consistent energy source and stable blood sugars. Complex carbohydrates are also typically higher in fiber, vitamins, and minerals when compared to simple carbs. Sweet potatoes, along with other orange colored fruits and vegetables, are high in antioxidants Vitamin A and Vitamin C, and are a good source of Potassium.
Sweet potatoes are considered a starchy vegetable and have 42 grams of carbohydrate per cup. What sets them apart from regular potatoes is their fiber content; they have 3x as much fiber as a regular potato, helping to slow down digestion and leaving you feeling fuller longer. Not only are sweet potatoes more nutrient dense then regular potatoes, but they will help keep you satiated. (This is probably why they have a reputation for being healthier than regular potatoes).
Healthy ways to prepare sweet potatoes are to simply bake them like a baked potato and top with a teaspoon of olive oil and sprinkle of salt. Adding a healthy fat will help you better absorb the fat soluble vitamins (like Vitamin A). Other ways to prepare them would be to steam, roast, and add atop a salad. Pairing your sweet potato with a protein rich food such as turkey, and a non-starchy vegetable (anything green) is a perfect way to create a colorful and balanced meal.