Question: What exactly in the meals I eat affects blood sugar level most (carbohydrate, fat, or protein)?
Answer: The nutrient and the diet that affects your blood sugar the most is carbohydrate. It is the nutrient that does raise blood sugar more than protein and certainly more than fat. It is, however, a nutrient that is contained in many, many important foods in our diet. It's the food that contains fiber; it's the food that's going to contain many important vitamins and minerals. Examples of carbohydrates are: fruits and vegetables, whole grain breads, milk, candy and cakes, sure, but it's also in pasta, cereal, bread. So you can see there's a wide range of foods that contain carbohydrates.
It's important when you have diabetes that you pick carbohydrates that are the most nutritionally valuable. Sometimes it can help if you think about those as kind of being like dollars that you have to spend. You want to spend it, sure, on some things that are exciting and maybe a little bit different and maybe special in some way; but you don't want to spend all of your dollars, your carb dollars, on that because you really do need to be spending them on things that don't have to be boring and dull and unpleasant or not fun to eat, but you do want to make sure that you're spending most of those carbohydrates on ones that mean something to your body, nutritionally.
Protein, because it's made up of amino acids, there are some little components of protein that can turn to sugar. If you eat a very high-protein diet, you may need to be paying attention to that component in your diet. But for most people, (it's) probably not terribly important to be counting the glucose production that comes from protein.
Fat does not have any carbohydrate content or raising of blood sugar that comes from it. However, fat is also -- or can be found -- in foods that may raise your blood sugar. You know, most foods are not made up of only one of those nutrients. Many, many foods that we eat are made up of carbohydrate and fat, or carbohydrate and protein, or carbohydrate, fat, and protein. So it is important that you learn about the amount of carbohydrate in the food, because it raises your blood sugar. But it means too that you don't ignore the fat content in the food that you're eating -- again, wanting to pay attention to the kind of fat that you're eating, and making sure that you get a good balance and that you get a good variety of foods.