Carbohydrates -Part 2: Sugar, Starch & Fiber
In our last post, we took a birds eye view of carbohydrates. We looked at a high level at what they are, what they do for us, and started to get into the different types of foods to consider.
There is another layer to carbs that we only scratched the surface of. Not all carbohydrates are created equal when it comes to energy – some provide rapid energy in small amounts and others more sustained, slow energy. The amount of carbohydrates in any given food exists on a spectrum. A lot of this has to do with the makeup of the carbohydrates.
Let’s explore what sugar, fiber and starch are. Then we can start to talk about where and how to go about our day of fueling with carbohydrates.
The word “sugar” is tricky. When most people talk about sugar, they are referring to sweeteners – like granulated sugar, powdered sugar, honey, and syrup (to name a few).
But sugar is not just sweeteners – it’s a type of chemistry that can be found naturally in many foods (like fruit, yogurt, and milk) or added to food in the form of sweeteners. Our body “sees” all these sugars the same. However, when we get sugar in natural foods (like fruit and milk), we get additional chemistries like fiber, fat, and protein that slow absorption and metabolism.
All sugars and sweeteners are made of 1-2 molecules, which makes them very easy to digest and break down. Sweeteners have little to no water, fiber, or nutrients associated with them. They tend to provide more energy per serving than “natural sugars,” which come prepackaged with water, fiber, and other nutrients.” But sweeteners don’t take up much space in the stomach compared to “natural sugars” making them an ideal source of rapid energy such as going into an intense workout or refueling in the middle of a workout.
But using foods high in sweeteners to fill your appetite means you’re missing out on nutrients and more likely to have irregular energy. Their low volume increases and limited additional nutrients means you’re more likely to eat more energy than what you need. But on the other hand, if you need energy but can’t tolerate much in your stomach, sweeteners are a decent fuel source.
There is no “best” or “worst” sugar. Our body sees all sugar the same way, whether it’s white, brown, maple syrup, honey, or “natural.” Instead, it’s about understanding how to balance sugar for function (e.g., energy) and enjoyment (e.g., cake).
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Starch is another type of carbohydrate found in foods. It has more molecules than sugar, but its chemistry is not as complex as fiber, so it can still be broken down by the body and used as fuel.
It’s the primary energy found in grains (flour, bread, cereal, pasta, rice, oatmeal, crackers) and some vegetables (potato, sweet potato, yams, corn)
Fiber is a type of carbohydrate that our bodies cannot digest. The chemistry is so complex that our body lets it pass right through. Because of its complexity, it tends to slow down our digestive process, leaving us feeling fuller, longer. Additionally, as it moves through our digestive system, it acts like a broom, sweeping along with it any other waste that needs to get removed from the body. Vegetables, beans, nuts/seeds, fruits, and whole grains are all rich in fiber.
Fiber is a great benefit if you’re trying to have sustained energy and feel fuller longer. But because it’s so hard to digest, it’s not ideal if you’re looking for rapid energy.
Energy in Different Forms
The amount of carbohydrate exists on a spectrum – some food groups don’t have as much energy available as others. And where it comes from on a plant often changes the density of the energy it provides.
Vegetables, for example, are mostly water with some fiber and a little carbohydrate.
Fruits have a bit more carbohydrate in the form of sugar and fiber.
Grains have even more carbohydrates from starch and sometimes fiber. And sugar (or sweetener) is pure sugar and provides the most energy per serving.
How to put it all together
Carbohydrates are not evil – they are a fuel source, that when used well, can do great things for the body. Most foods come with a label (or can be looked up online), and from there, if you understand what to look for, you can choose foods that work best for your goals.
You can look at a label and understand exactly what a food is made of and how your body will use it as fuel. Let’s look at an orange vs. an 8 oz glass of orange juice. Scroll down to the portion where it says “carbohydrate.” You’ll see that a glass of orange juice has 26 grams of carbohydrate. 21 of those grams come from sugar, and ½ gram comes from fiber. But you’ll also notice that 21 + ½ = 21 ½ (not 26). Labels don’t have to label for starch. Essentially, most of the energy you get from orange juice is from sugar – it’s a rapid fuel source and won’t keep you full for long.
When you look at the orange, it has 15 grams of carbohydrate, 12 of which are from sugar. And 3 of which are from fiber. It will give you rapid energy, but not as quick as orange juice.
There is a lot to unpack when it comes to figuring out what and when to eat. Here are some basic goals, principles and examples in determining the types of carbohydrates to pick.
Please note exact portions vary depending on your energy needs. Additionally, some stomachs are more sensitive than others so may require additional modifications.
MEET THE AUTHOR: REBECCA TOUTANT, MA, RDN, LDN, CDE
Rebecca is a registered dietitian, personal trainer, and certified diabetes educator living and working in the Boston area.
Learn more about Rebecca and her background here: Fuel 4 Fitness – Rebecca Toutant