If you start hearing the Imperial March from Star Wars when people bring up carbs, you’re not alone. Carbohydrates seem to be our culture’s current nutritional demon, taking a sharp turn away from saturated fats. The proliferation of low-carb and ketogenic diets has made eating carbs seem like turning to the Dark Side. After all, they do have cookies.
Let’s take a moment to sort through fact and fiction when it comes to carbohydrates.
Pop Quiz: Which of the following foods is NOT a Carbohydrate?
B) Bread, Cereal, Pasta
C) Leafy Greens
D) None of the above
If you guessed D, you’re right. Your healthy cauliflower, kale, and sweet potato dish are all forms of carbohydrates. We’re going to dig in and take a look at what a carbohydrate is, the different types of carbs, and how they affect your body.
What is a Carbohydrate?
Simply put, carbs are molecules made up of carbon, hydrogen, and oxygen. Without getting too deep into the specifics, these molecules form chains and the larger the chain the more difficult it is for the human body to break it down. When it comes to human consumption, this pretty much ranges from sugar on one end of the spectrum to fiber on the other.
What are the different types of carbohydrates?
Monosaccharaides, also known as simple sugars, are made of just one carbohydrate molecule. The two of these we see most often when it comes to food are glucose and fructose.
Mitochondria may be the powerhouse of the cell — they generate the molecule ATP which the body runs on — but glucose is its primary fuel source. This is especially true of moderate exercise, which is why you’ll see distance runners carrying around packets of “energy gels” for a quick hit of glucose to keep them going.
During non-exercise activity, mitochondria can also make ATP from fat. However, it is a more difficult process so your body is going to look to glucose first and turn to fat when you’re running low.
This is part of the theory behind the ketogenic diet. By depleting your body of glucose, you give your cells no choice but to use body fat as your energy source and you probably have a near-endless supply of it.
Because glucose is such a major part of the body’s energy system, our hormones are very responsive to it. After eating, that sweet, sweet glucose starts to float around in our blood and signals two important hormones – insulin and leptin. Insulin helps to move the glucose from our blood into our cells. Leptin makes us feel satiated and tells our brains we’re not hungry anymore.
Which brings me to fructose. Fructose is commonly known as “fruit sugar” and is found in fruits, root vegetables, honey, and agave. You may also hear of it in terms of “high-fructose corn syrup” or HFCS. Fructose is generally sweeter than glucose, so it became economical for companies to use this version of sugar to sweeten foods.
Therein lies one of the biggest problems with our food supply today. Fructose has to be turned into glucose in the liver before it can stimulate leptin production. In short, foods high in fructose take longer to make you feel satisfied which in turn makes it easier to overeat. While some glucose can be stored in the form of glycogen, the excess gets stored as adipose tissue–more commonly known as body fat.
Wait, Ray! Are you telling us not to eat fruit anymore?
Whoa, hold those horses! HFCS plays a large part in overeating processed foods, but that doesn’t make naturally-occurring fructose the villain. The fructose found in fruit and root vegetables occurs alongside water, nutrients, fiber, glucose, and sucrose as well which make them more complete food sources.
Sucrose is one of several disaccharides we get in our diets. Disaccharides are made up of two combined carbohydrate molecules that need to be broken apart before they can be used by our bodies. Sucrose, for example, is made up of one glucose and one fructose molecule.
Other examples of disaccharides are maltose (typically found in grains), trehalose (typically found in mushrooms), and lactose (typically found making me unhappy because I love dairy and, like 65% of the world’s population, I can’t process it properly.)
Disaccharides are still considered sugars, but take a little more time to break down than glucose.
Polysaccharides are long chains of carbohydrates that come in four forms. We actually already discussed one of them in the glucose section – glycogen. The other three are chitin, starch, and cellulose.
Animals store extra carbohydrates as glycogen. Typically, at rest, these energy stores won’t be touched and the body will prioritize blood glucose then fatty acids. But, during physical activity, the body will tap into these sources.
The human liver stores around 100-120g and around 400-500g in our muscles — which is why extra carbs can give your muscles that swole look. For a steady-state endurance activity, stored glycogen will last most people around an hour and a half. Once glycogen is depleted energy levels can drop drastically, which people typically call “hitting the wall”.
The next polysaccharide, chitin, isn’t one that’s typically part of the human diet. In fact, there doesn’t seem to be a consensus on how much, if any, chitin can be digested by people. Chitin is found in exoskeletons of crustaceans and insects and the cell walls of some fungi.
Starch is for plants as glycogen is for people and animals. Its stored energy for the plant to use. And us too. Biting into a delicious ear of corn, dipping into a chickpea hummus, or crunching up some delicious potato chips are all ways we dig into starch-based foods.
The last type of carbohydrate ic cellulose, which is found in the cell walls of plants and helps give plants structure. And, when it comes to human nutrition, it is a major component of dietary fiber. Even though humans can’t absorb cellulose, it helps keep the digestive tract moving.
We could talk about the nuances of these types of carbs for a good long time, but let’s move on to talking about what it means for you and your eating habits.
No Carb, Low Carb, or Mo’ Carb?
While everything may suddenly seem like keto this and keto that, low-carb diets have a history going back to the 1860s.
In 1863, a man named William Banting released a Letter on Corpulence, Addressed to the Public. This letter detailed his successful battle against obesity with the help of Dr. William Harvey. Harvey was not a dietician, but an ear, nose, and throat doctor. But he did give Banting the advice to cut starch and sugar from his diet.
Through the next century and a half, various diets promoting limited sugars and starches have cropped up. The Atkins Diet, the Stone Age diet, the Paleo diet, the Zone diet, the South Beach Diet, and the Ketogenic diet.
When it comes to picking “the best diet”, we may go through dozens of diets and plans looking for the results we want. So let’s take a quick look at what no-carb and low-carb diets mean compared to the standard western pattern diet.
“No Carb” – Ketogenic Diets
Reach a state called “nutritional ketosis” is the primary goal of the keto diet. At that point, your body no longer has glucose to draw on. So your body turns to fat for its primary fuel source.
Generally, keto recommends eating less than 50 g of carbohydrates a day. Most importantly, keto is a high-fat diet with almost 70% of calories coming from fat, 25% from protein, and 5% from carbs.
A ketogenic diet may improve insulin sensitivity, reduce appetite, and improve cholesterol and triglyceride levels. However, the process of getting into ketosis can be very taxing on your body and can produce what is called the “keto flu.” Symptoms include fatigue, irritability, headaches, and a general feeling of weakness. Because keto is so low in carbs, fruit is usually off the menu and so are many other sources of dietary fiber like beans and whole grains, so constipation may occur.
Some proponents point to keto’s effect on insulin levels as the reason keto can promote fat loss, but the reality is that fat is a highly satiating food and without the blood sugar rollercoaster, you’re less likely to get intense spikes of hunger.
A low carb diet is one in which about 10-30% of daily calories come from carbs. Generally, this is less restrictive and less extreme than keto to adapt to. Usually, when limiting carbs, people will eat more protein and vegetables to fill the void left by limiting carbs.
As with ketogenic diets, people who eat lower-carb diets tend to experience less hunger, improved cholesterol, and improved insulin sensitivity.
Mo’ Carbs – Standard American Diet
The Standard American Diet or SAD is, well, sad. Generally, 50-55% of caloric intake comes from carbohydrates, most of it from highly processed foods. 35% of calories typically come from fat and only 15% from protein.
Yikes! This is a recipe for high blood sugar, excessive calorie intake due to hunger, and a lack of lean muscle. Or is it?
The New England Journal of Medicine conducted a study of various weight-loss diets with different carb, fat, and protein compositions — including ones that were 65%, 55%, 45%, and 35% carbohydrates.
Every group lost weight. On top of that, every group had improvements in insulin sensitivity, blood sugar, and triglyceride levels. And, at a two year follow up, more than 50% of the participants had maintained a loss of more than 5% of their body weight, enough to reduce risk factors for cardiovascular disease and diabetes.
So what does this mean for you?
It means there is no magic number when it comes to carbs. It all comes down to your personal preference, the foods you like, and the foods that make you feel like you are accomplishing your goals.
The NEJM study did show that generally lower carbohydrate diets showed more improvement than higher carbohydrate diets. But the lowest participant group still had more carbs than most “low-carb” diets. So, I think it’s safe to say you don’t have to rush to cut carbs if you don’t want to.
As a general guideline, try to get your carbs from sources with more micronutrients — fruits, legumes, whole grains, potatoes, and other tubers– and keep the chips, cookies, and cakes for occasional treats.
I know, when it comes to looking for the “right” diet, it can be disappointing to hear that there is no one perfect answer. But, it can also be incredibly freeing. If you want to work with a fitness coach who can help with nutrition, check out our offerings in the personal training tab.