As a diabetic educator, I often get a lot of questions about carbohydrates, more so after my last blog post, and a lot of the questions have to do with both the terminology that is employed when describing them and how much a person should eat. I hope to explain some of the questions that I get, and also deal with a few of my pet peeves in the process.
1. "Are complex carbohydrates better than simple carbohydrates?" Typically the subtext of this question is really "Are complex carbohydrates better for my blood sugar than simple carbohydrates?" To answer this question, I want to explain a little bit more about what "simple" vs. "complex" means when used in front of the word carbohydrate. A simple carbohydrate has only one sugar molecule or two bonded together (think about a necklace with only one bead on it, or a strand of single beads strung together). A complex carbohydrate has three or more sugars bonded together (think of a strand of different kind of beads woven together). Now think about dipping either the simple necklace or the complex necklace in acid; both of them are going to break apart at about the same rate. When a simple or complex carbohydrate gets hit by amylase, it starts breaking down at a similar rate. So the term "simple" vs. "complex" is merely a description of the chemical structure, period. It really doesn't tell us about how quickly something affects your blood sugar.
Now, where this gets confusing is that certain carbohydrate foods, often the "complex" ones, may be higher in fiber, and they also might take longer to consume, which MIGHT impact your blood glucose levels. Fiber slows down the emptying of your stomach, so in theory certain foods might take longer to get to your intestines and therefore your blood stream. As far as consumption time, think about the difference between four ounces of orange juice versus a small orange. Most people can knock back that amount of OJ in a couple swallows--so you get 15 gm of carbohydrate in your system pretty fast. With that orange you have to peel it, chew on it, spit out the seeds, oh, and you also get some fiber to slow down the emptying of your stomach. That orange is still going to impact your glucose levels, but you might see a slower rise.
2. "But I have diabetes, and I was always told that I needed to consume 'fast acting carbohydrates' when my blood sugar is low." Once again, the simple vs. complex terminology is really only a description of chemical structure. A "fast acting" carbohydrate is something that you can ingest quickly with a minimum of chewing and swallowing, that's all. So, if someone with diabetes (who takes medication or insulin) has a blood glucose level below 70; they need to stop a dangerous situation from getting more dangerous--they don't need to be chewing on a sandwhich or eating any fiber or fat to slow down the emptying of their stomach. That's why someone having hypoglycemia (aka low blood sugar) is normally told to drink four ounces of juice, or half a can of regular soda, etc. Now, every person who has had Type 1 diabetes (or Type 2 treated with insulin) for a long time will have their own "favorite" for treating a low; I have had some people tell me saltine crackers work the best (no fiber, can chew on several at once), some people tell me chocolate bars (although this is not normally reccommended because of the fat content), some people prefer to use the manufactured glucose tabs or gels for convenience. Each person needs to figure out what works best, but you don't want to confuse "simple" with "fast acting" necessarily.
3. "I've heard them talk about 'good carbohydrates' on TV/the radio/the internet. What are they?" Basically if the term "good carbohydrate" is used in a commercial or on the front of the box, the only thing it means is "We are trying to sell you this product." After I give that answer, I will usually give my definition which is twofold. Number one, that food is only "good" if it fits within your carb/calorie budget. If you are like yours truly who needs to keep the carbs to no more than about 30 per meal, then a plateful of pasta is way over that. In other words, some foods like pasta/bread/rice tend to have a high caloric density--by the time you eat a portion that fits your budget you wonder where the rest of it is! So that's why some people give up certain foods because they want more volume. Number two, does that food have anything good for you? A piece of fruit will give you fiber, lots of vitamins and antioxidants; whereas two Oreo cookies will give you.....two Oreo cookies. So that piece of fruit could be considered a "good" carbohydrate, but only if you eat one piece, etc. That sweet potato might be a good carbohydrate, but not if it's covered with maple syrup and marmallows and margarine (you are all horrified to realize this, I know).
4. "What about the glycemic index?" The glycemic index ESTIMATES how much each gram of available carbohydrate (remember about subtracting the fiber) in a food raises a person's blood glucose level after you eat and compares it to the impact of pure glucose. On this scale glucose has a glycemic index of 100 and other foods all have a lower glycemic index. Keep in mind, however, that the GI can be affected by a lot of different things, like how well something is cooked, the ripeness of the fruit, what other foods you are eating with the particular food of note, and even the acidity of the overall meal. For this reason, some diabetologists recommend that people forgo the GI and instead insist that each person with diabetes do extensive testing of their own blood glucose levels to see how different foods and combinations affect them (I tend to be in this camp as well).
For people who are in that pre-diabetic state (or who have a family history of insulin resistance and are trying to be careful), you probably aren't testing your blood glucose; it wouldn't hurt you to look at the GI because a lot of the foods lower on the scale tend to be richer in nutrients--but not always, and there are some foods, like watermelon, that actually have a lot of nutritional value! And one of the other problems I have noticed is that when people see something has a "lower" GI (like Dreamfield's pasta), they tend to (you guessed it) pig out on it, completely forgetting that the AMOUNT you eat is just as important. At that point it would be more useful to consider the glycemic load (GL), which takes portion sizes into account. For example, one of the foods that people have traditionally shied away from when they told they are diabetic is carrots, because they have a higher GI. What they don't know is that the GI was established by feeding healthy individuals 50 grams of available carbohydrate, which for carrots equals about a pound and a half of carrots. So if one uses the GL, you could eat a carrot, maybe make some carrot fries, but you probably don't want to eat the whole bag of baby carrots in one sitting. Once again, you know who you are.
Side note: Typically health care people have shied away from recommending the GI and the GL because it's "too difficult" to follow, and I wouldn't use this with my elderly patients who have trouble remembering to eat, let alone calculating out GL. Normally, however, my way of thinking says "get all the information and decided for yourself whether or not you can follow it."
5. "Do I need carbohydrate foods to survive?" Here is where we start playing with semantics. Technically, we could get what we need nutrient wise from eating protein, healthy fats, and vegetables and we could survive quite well. Typically when dietitian's get asked this question, however, they usually say "no" and start pointing out all the nutrition deficiencies you can wind up with. For some people it's because they are still suspicious of lower carbohydrate plans despite evidence pointing out that they can be beneficial, but for others it's because you work everyday with people that have the best of intentions to eat plenty of vegetables and vary their protein sources (and even include organ meats!), but they just don't do it for whatever reason. If you have already achieved a varied diet that doesn't include starches and don't even miss bread, etc, I think that is wonderful. The rest of us, however, would really like to eat our tacos in an actual corn
tortilla sometimes and still keep our calories and carbohydrates under control, and I think as long as you are meeting your health goals you are fine. I guess you could say some of need carbohydrate for our mental health more than anything, and I happen to like variety. (I actually had a lot of fun reading about The Aboriginal Eskimo diet), but then I'm weird like that.)
6. "Speaking of mental health, is it ok to purchase the low carb pasta, etc?" Maybe. I've given some tips for making that decision in a previous post. Spending excess money and ultimately consuming more calories is something that I have noticed to be a big problem in my practice, however.
7. "How much carbohydrate should I eat." I knew that was coming. First of all, the amount you can tolerate is going to depend on your metabolism, so if you are a blood sugar tester, test after meals for a couple weeks to see what you can handle. Second, keep in mind that we as human beings are a pretty hardy bunch, if you go one gram over your meal limit you will probably be ok. Third, some people start testing their urine for ketones to see if their intake of carbohydrate is low enought that their body is burning fat for energy as glucose is no longer a readily available source of energy. (***Warning. Warning. Warning. I am talking about KETOSIS which is a normal function of the body when glucose is not readily available. I AM NOT TALKING about KETOACIDOSIS which is severe ketosis in the presence of an insulin deficienciency and elevated blood glucse that can be deadly to a person with Type 1.***) Anyway, so here's the ballpark, since you asked so nicely:
If you have a lot of weight to lose or you are a person with Type 2 diabetes who needs serious blood sugar control help: 0-50 grams of carb per day. You probably don't want to stay here more than two weeks as you start depriving yourself of the good things in fruits and vegetables.
If you're more in that "I've got to lose some weight" or "my blood sugar control could be better": 50-100 grams per day. You actually get to work things like fruit, vegetables, and other tasty and nutritious things in here. I find it a little easier to stay here.
If you are ok with your weight and/or blood glucose control but you want to stay healthy (or have a history of insulin resistance): 100-150 grams per day. Any more and your calorie intake might start creeping up or your blood glucose might start acting funny.
***Remember, these are ballpark. If you have already found you need to stay <100 grams per day to keep your blood glucose under control, good for you. If you are a serious triathlete, you are probably going to need more.***
Take home message--The amount of carbohydrate you can consume and still meet your health goals varies by individual. Take care to watch the amount and the nutritional value of what you are getting.