I have been reading articles from several "reputable" sources about yams & sweet potatoes. The problem is they contradict each other as to how to tell them apart. Folk wisdom says orange flesh is yam, white or cream flesh is sweet potato. Can you please define what the actual tubers look like so I know what I am buying? Which has the more acceptable nutrition for diabetics?
Yams and sweet potatoes are commonly confused with each other in the United States; this is because most grocery stores label orange variety of sweet potatoes as yams to distinguish them from the white variety. I believe that in most stores we are purchasing sweet potatoes even if they are labeled as yams. Yams are harder to find and you may have to go to an international grocery store to purchase them. Botanically yams are in a different group than sweet potatoes. Compared to sweet potatoes, yams are starchier and drier.
Assuming that you are probably eating sweet potatoes, if cooked without added ingredients, nutritionally they are high in carbohydrate, fat and cholesterol free, low sodium, very rich in Vitamin A and high in Vitamin C and contain fiber. Estimated nutrient content for one cup cooked is approximately 40 grams Carbohydrate and provides over 700% of daily Vitamin A.
I didn't find specific nutritional data on white versus orange sweet potatoes varieties but based on color I would assume that the deeper colored varieties would have more vitamins/antioxidants as this holds true for other foods.
For diabetes you will need to consider the carbohydrate content and how that fits with your individual meal plan and goals for diabetes.