Macronutrient Primer: Carbohydrates
Carbohydrates are a misunderstood macronutrient in the fitness industry. It’s quite alarming how many people think they are insulin resistant or can’t tolerate carbs. This article will discuss everything you need to know about what a carbohydrate is, how it impacts you, and how you can use them for reaching optimal performance and body composition. First, a couple of terms need to be defined.
Insulin: Insulin is the “storage” hormone of the body. When you eat, specifically carbohydrates, and protein to an extent, your pancreas releases insulin. Cells in the body, both fat and muscle, can absorb the sugar when insulin is released.
Insulin Sensitivity/Resistance: Insulin sensitivity and resistance is the relationship between how much insulin needs to be released to store and dispose of a certain amount of glucose. You are insulin sensitive if your body releases a small amount of insulin for a certain amount of blood glucose. You are insulin resistant if your body releases a lot of insulin for that certain amount of blood glucose. Insulin sensitive people are those who are generally leaner and healthier, and insulin resistance is for those who cannot handle blood sugar well. Type II diabetics are the extreme case of insulin resistance. The level of your insulin sensitivity has to do with body composition, genetics, and activity level.
What are carbohydrates?
Carbs are organic molecules in the body that are broken down into glucose (sugar). Carbs are broken down into two categories: Simple and Complex Carbohydrates. Simple carbs are smaller, as they’re either one or two molecules linked together. Some forms of simple carbohydrates are glucose and fructose. Complex carbs are larger, and have more than two sugar molecules linked together.
No matter what kind of carbohydrate you consume, it ultimately is broken down into sugar, and then it is absorbed by the body. It doesn’t matter if its Skittles or high fiber oatmeal, it will be broken down as sugar. The difference between these food sources is their digestion speed. Low glycemic carbohydrates are digested slowly, and do not spike insulin. Simple carbohydrates are digested rapidly and lead to a larger insulin spike.
What do carbohydrates do in the body?
Carbs are the primary source of immediate energy for the body, and carbs and glucose also help the brain and body function normally. Where walking is solely supported by fat oxidation, sprints, jump rope, or other types of vigorous activities primarily rely on carbohydrates to fuel the energy for the body.
What is the Glycemic Index?
The glycemic index is a measure of how quickly blood sugar levels rise after eating. Pure glucose, or sugar, has a glycemic index of 100 as it gives the quickest increase in blood sugar after consumption.
Low Glycemic Index (GI) foods are foods that have a GI of 55 or less. These foods include beans, peanuts, oats, most vegetables, brown rice, and most sweet fruits, like strawberries, mangoes, and peaches.
Medium GI carbohydrates have a GI of 56-69. These foods include boiled potatoes, bananas, and pita bread.
High GI carbohydrates have a GI of 70 and higher. These foods raise blood sugar the most. Some examples of high GI carbs are white bread, white bagels, glucose, and pretzels.
Insulin on Fat Burning
Insulin again is the storage hormone. When insulin is elevated, lipolysis is essentially stopped. Lipolysis is the process of triglycerides (fats) being broken down from fat tissue for eventual oxidation (burning of fat). Lipogenesis on the other hand is the process of storing energy into these fat cells. Since insulin is a storage hormone, it promotes lipogenesis and the uptake of fatty acids into fat cells. It also, promotes storage of nutrients into the muscle cell as well. Moral of the story is: when insulin is elevated, lipolysis is “turned off” for easier terms, and thus fat oxidation cannot take place.
What does this mean?
Well, low glycemic carbohydrates will elicit the smallest insulin responses. High GI carbs will elicit the highest insulin responses. When insulin is raised, it will stay elevated until all the sugar in the blood is disposed of into cells. Sooooo, low glycemic carbs will allow for a quicker drop of insulin, and back to lipolysis. For those who are insulin resistant, picking lower glycemic carbs should be a priority.
While low glycemic carbs are usually better for body composition because it doesn’t result in large insulin responses, there are times where an insulin spike can be beneficial. Insulin is a double edged sword. While raising it all willy nilly can result in lessened fat oxidation and fat storage, spiking it after a workout can help drive nutrients into the muscle cells since they’re in a state where they are very susceptible to nutrient uptake.
So someone who is insulin resistant, and releases too much insulin in response to carbohydrate consumption, can have trouble staying lean with high carbohydrate consumption. For those who are insulin sensitive, higher carbohydrate diets can be used and won’t usually have adverse effects on body composition.
Please note this: YOU CAN ONLY GET FAT WHEN YOU’RE IN A CALORIC SURPLUS. You can spike insulin all you want, but if you’re under eating and there’s not extra energy (calories) to be stored, you cannot physically gain fat. Again, “calories in” in relation to “calories out” will result in weight gain or weight loss. This is where the whole “If It Fits Your Macros” diet comes into play: if you’re tracking your calories and macros, and a bag of skittles can fit into what you eat for the day, then have that bag of skittles.
How do I tell if I am insulin resistant or insulin sensitive?
There are a few ways to tell if you are insulin sensitive or resistant. One way is to purchase a blood glucose meter and do a test. I’m not going to explain this though, if you want to go this route I recommend Googling it.
Those who are insulin sensitive can handle a diet higher in carbohydrates and feel just fine. In response to a carbohydrate heavy meal, they feel very energized and ready to go.
Those who are insulin resistant can’t tolerate carbs very well. In a high carbohydrate diet, they feel very bloated and tired all the time. Those who are insulin resistant usually get very sleepy after a high carbohydrate meal, from a sugar crash.
I recommend to experiment with different diets and see how they effect your energy levels and body changes. As of now, my diet consists of a 35/35/30 (Protein/Fats/Carbs, in percentages of total calories). This has given me the best results in terms of energy levels. The leaner you get, the more insulin sensitive you can become. When I was heavier and out of shape and just started getting into working out, the diet I used was 35/55/10. Exercise also helps with insulin sensitivity.
Carbohydrates Around the Workout
So now that we have a basic understanding of how insulin affects us, how should we use carbohydrates around our workout? In my opinion, low glycemic carbohydrates are best before a workout. Since they’re digested slower, they provide more energy for a longer time. They’ll also keep blood sugar levels stable and can ward off the blood sugar crash some of us are susceptible to. Good choices are brown rice, oats, and whole-wheat bagels.
After a workout, our body is craving nutrients and insulin sensitivity is sky high. Also, muscle cells will be ready to take in these nutrients for recovery. If you ever want to cheat on your diet, now is the time, and it could be beneficial. Some people like to have a whey protein shake mixed with straight glucose or maltodextrin to spike insulin, and help drive those amino acids from the whey into muscle cells to help fuel recovery.
Low glycemic carbs are fine post workout too, as you don’t need a large insulin spike for muscle recovery to take place and for muscle cells to take up glucose. I, for one, like to consume old-fashioned oats post workout, or P28 Flat Breads and make burritos with brown rice or quesadillas with them. Again, experiment and see what works best for you.
So there you have it. Again it’s much more complex than how I just painted it, but it’s a good start to understanding carbohydrate consumption and the hormone, insulin. Understanding the glycemic index can help those who are insulin resistant control their insulin, as controlling insulin can help you stay leaner when consuming carbs and prevent blood sugar swings and crashes. To recap, carbs don’t make you fat, EXCESS CALORIES make you fat. Remember that next time someone says, “Carbs past 6:00 PM will be stored as fat.” Because that’s false, and they’re an idiot. When you eat your carbs, and any macronutrient for that matter, timing is largely irrelevant. What matters is total calorie consumption for the day, and macronutrient consumption.
Information provided by Richard Aponte. Thank you Richard!