Mythbuster: Are Carbohydrates Really Bad For You?
Let’s discuss distinguishing between complex carbohydrates and simple carbohydrates. For example, there is a profound difference between 50g of sugar and 50g of oats. They both weigh the same, but how nutritionally dense they are and how they affect your body's metabolism is dramatically different.
Complex carbohydrates are chains of simple carbs strung together in long, complex chains. Complex carbs are better because (a) they contain vitamins, minerals, and fiber that are important to your health and (b) they generally do not have as dramatic of an influence on your blood sugar. Complex carbs are generally called starches and healthy sources include green vegetables, whole grains (oatmeal, pasta), starch-heavy vegetables (potatoes, sweet potatoes, corn), beans, lentils and peas.
In contrast, simple carbohydrates are simple carbs that are not strung together in long, complex chains. Examples include glucose, fructose, dextrose. The significance of this is (a) they do not contain the same vitamins, minerals, and fiber that you find in complex carbs and (b) they generally have more dramatic influence on your blood sugar. Examples would include sugars, syrups, jams, fruit drinks, soda and candy and these contain what are often termed refined carbs.. You may hear them referred to as FODMAPs, which stands for "Fermentable Oligo-, Di-, Mono-saccharides And Polyols."
The lack of nutritional content in refined carbs is somewhat obvious and I won’t dive into an explanation. It goes without saying, the lack of vitamins, minerals and fibers in any food compared to an alternative is a bad thing.
On the other hand, the influence on blood sugar is significant and requires explanation. Simple carbs are more easily absorbed in the gut and readily available for use. In small amounts or during exercise, this is helpful, but in excess and over an extended period of time, this causes multiple metabolic problems. The first is that it will eventually become stored as fat, leading to weight gain. The second and perhaps more important, is that your cells develop resistance to insulin, a hormone responsible for getting sugar into the cells, as a result of being overly saturated with these simple carbs. The consequence of this is that you eventually can develop type 2 diabetes from this and all the issues related to that (kidney, eye and foot disease, among others)
So now that you understand the difference between simple and complex carbs, there are a few more important points to make.
The first is that carbs are one of three macronutrients, which also includes fat and protein. You need all 3 macronutrients for survival. Your body is smart and capable of converting fats and proteins to carbohydrates, namely glucose (sugar), but this is not an efficient use of resources. So in order to be metabolically efficient, you do need some carbohydrates at baseline.
The trick is (a) how many and (b) what type of carbs. In general, for the average person, 20% of your dietary intake should be carbs, and the other 80% should be a mix of fat and protein. This varies somewhat depending on your level of physical activity and any medical problems you may have.
20% of what you may be asking? 20% of your total daily calorie intake. According to the NIH, the average adult male needs 2,500 calories per day and the average female needs 2,000 calories per day. Again, this will fluctuate based on your height, weight, level of physical activity and goals. But this is a rough estimate. I would encourage you to look into total daily energy expenditure and a calorie counter if you want to know more.
The second thing you need to understand is the type of carbs you are consuming. There are simple carbs in some healthy foods such as certain vegetables, fruit and milk. These should be your source of simple carbs. If you’re eating table sugar, brown sugar, corn syrup, honey, maple syrup, molasses, jams and jellies, fruit drinks, soft drinks like soda, candy, baked goods or chips you’re doing it wrong. Remember, these are going to significantly increase your risk of gaining weight and developing diabetes. They also have virtually no vitamins, minerals or fiber.
Health sources of of carbs are complex carbs. These should come from green vegetables, Whole grains (oatmeal, pasta, and whole-grain breads), Starchy vegetables (potatoes, sweet potatoes, corn, and pumpkin), and Beans, lentils, and peas.
So in summary, to get back to the initial point, carbohydrates are not inherently bad. They are an important and efficient source of energy for our body and brain. Your goals with carbohydrates will be to not overindulge, i.e. do not consume them in excess. As discussed, limit your intake to 20% of your total daily calories and do not consume them and exclude other important foods. When choosing carbs, choose complex carbohydrates over simple, refined carbs for their nutritional value and because they are better for your body’s metabolic profile.