The Real Facts About Carbohydrates Explained: Mythbuster Edition
Does the word “carbs” send shivers down your spine? There are so many myths and facts about carbohydrates that people are genuinely confused about, like “no carbs before bed” and “carbs make you fat”. With so many sneaky myths about carbs out there, it’s no wonder people are going keto, avoiding carbs before bed, and thinking that all carbs are bad (spoiler alert – they’re not bad).
We’ve heard all the myths before and now it’s time to clear things up. This myth-buster edition is dietitian-approved information that you can trust.
What Are Carbs?
Before we get into explaining the real facts about carbohydrates and busting those carb myths, let’s get down to the basics.
Technically speaking, carbohydrates are one of the three macronutrients the body needs in large quantities to give your body energy (the others are protein and fat).
There are three main kinds of carbs:
Most foods that contain carbohydrates will be a combination of all three types of carbs (i.e. sugar, fiber, starch).
Carbohydrates are your body’s main energy source. When carbohydrates are no longer coming in and your stored carbs (called glycogen) are depleted, the body turns to burning fat as fuel (hello, ketosis). Ketosis is a survival mechanism: your body strongly prefers carbs for fuel.
Let’s get one thing straight – carbs do a body GOOD. They fuel your red blood cells, nervous system, and each and every muscle in your body. They also prevent protein from being used as an energy source. This is another good perk because our body prefers using protein to build and repair body tissue, not for burning for fuel.
Surprisingly, carbs can help prevent weight regain, and yes, even promote weight loss.
Also, carbohydrates support heart health and brain function. In fact, the recommended dietary allowance (RDA) for carbohydrates, set at 130 grams/per day, is based on the minimum amount of carbohydrates your brain and liver need for prime functioning, plus a little extra for good measure. Most of us need more than that, BTW.
Simple and Complex Carbs – What’s the difference?
Buckle up, Buttercup: this is where things get a little science-y.
During digestion, carbohydrates are broken down into simple sugar molecules, most of which are glucose. These simple sugars are small enough to enter each of your body’s cells, providing them with energy.
The exception to breaking large molecules down into simple sugars rule is fiber – your body can’t break this stuff down. Unlike starches and sugars, fiber slowly passes through the body mostly undigested, helping to stabilize blood sugar and regulate digestion.
And although we cannot digest fibers, the healthy bacteria living in your GI tract – the microbiome – feed off of fiber. Enough fiber in your diet fuels a happy, productive microbiome.
Simple carbs are well, simple. They consist of just one to two sugar molecules and are absorbed quickly. While they can provide a quick boost if you’re feeling starved, eating primarily simple carbs can lead to a blood sugar roller coaster, leaving you hungry, cranky, and tired soon after.
Sugars and sweeteners are often referred to as simple carbohydrates. Examples of simple carbohydrates are:
- Regular and brown sugars
- Corn syrup
- Fructose (the sugar found in fruit)
- Maple syrup and honey
- Added sugars in packaged foods
Next up? Complex carbs!
Complex carbohydrates take longer to digest because they’re bigger, more complicated and therefore take longer to break down into small enough pieces that your cells can absorb them.
You can picture a complex carb like a very beautiful long pearl necklace with many strands woven together. Each little bead is like a simple sugar, all together you have a complex carbohydrate.
Eating foods rich in complex carbs can give you longer-lasting energy levels and help fill you up. Sources of complex carbs are often rich in fiber, too. Starches and fibers are usually found in whole foods, such as:
- Starchy vegetables (like potatoes)
- Legumes (beans, peas, and edamame)
- Whole Grains (quinoa, whole wheat, brown rice)
Keep in mind, many foods that contain carbohydrates have a mix of simple and complex carbohydrates; for example, fruit contains natural fruit sugar (fructose, a simple carb) as well as dietary fiber (a complex carb).
The main thing to remember here is that from a nutrition standpoint, not all foods that contain carbohydrates are created equal. You want to focus on getting most of your carbohydrates from less refined and less processed, whole-food sources that are high in fiber.
Remember, fiber’s the carb that isn’t digested and passes through you slowly. Therefore, it can keep you fuller longer and keep those blood sugars stable. P.S. Most of us are not getting enough fiber each day. Here are 10 Easy Ways to Sneak Fiber Into Your Diet.
Okay; you’re feeling confident with your carbs 101 info. Ready to bust some myths? Let’s dive in!
8 popular myths and facts about carbohydrates
Get ready friends, it’s time to debunk some popular carb myths and leave you comfortable with the real facts about carbohydrates. You’ve probably heard these myths before. They float around Instagram, Facebook, and your friend group.
I’m here to tell you what’s true and what’s not. And P.S. It’s all backed by science.
Myth #1: Carbs are only pasta and bread
Where that myth came from:
When you hear “carbs”, you probably envision the unlimited breadsticks and endless bowls of spaghetti at Olive Garden. True, these are high-carb foods, but they aren’t the only ones!
What foods have carbs? Most things that you eat, actually.
Carbs are found in high amounts in grain products like bread and pasta, fruit, as well as starchy vegetables like potatoes, beans, chickpeas, and lentils. There are even small amounts of naturally occurring carbs in some animal and seafood foods – like shrimp. Nuts and seeds have a few carbs, but they’re higher in protein and fat.
Think you’re avoiding carbs when you chow down on a spinach salad? Think again. A cup of spinach has a couple of grams of carbs, and so do those other veggies on top of your salad.
So what’s the bottom line here?
Most foods have carbs; if you are aiming to avoid all of those foods, you’ll be missing out on a lot of delicious, nutritious foods. Welcome carbs back to your dinner plate, pretty please! They’re not bad – let’s bust that myth next.
Myth #2: All carbs are BAD
Where that myth came from:
There are a lot of carb-rich foods that frankly aren’t that healthy for you. I’m talking about doughnuts, candy, cookies, potato chips, and yes, that endless bread basket at Olive Garden.
It’s easy to see how thinking of those carb sources as “bad” can lead to generalizing that all carbs are bad. But they aren’t!
And let’s not forget about the gluten-free movement. With the increasing popularity of gluten-free eating, it’s no wonder carb-rich foods (wheat being a main source of gluten) leave a bad taste in your mouth.
If you only take away one of these facts about carbohydrates after reading this article, let it be this one. Carbs do a body GOOD. Your body needs them for energy. A carbohydrate-deficient diet can cause headaches, fatigue, difficulty concentrating, nutrient deficiencies, constipation, the list goes on and on.
Don’t worry, there are many good-for-you carby foods to choose from. When possible, look for those rich in fiber, like fruit, vegetables, legumes, and whole/ancient grains. Remember, fiber helps fill you up, without filling you out.
As for the gluten issue, there’s no evidence to support that gluten causes harm or inflammation for most of us. Unless you have gluten intolerance or Celiac Disease (a disorder in which eating gluten triggers an immune response in the body), you’re welcome to eat and enjoy gluten-containing foods.
If you still think you don’t tolerate gluten well and want to avoid it, go for it! But that doesn’t mean you have to avoid carbs or even limit your carb intake. There are plenty of high-carb options that don’t contain gluten: quinoa, rice, gluten-free oats, fruit, potatoes, legumes, etc.
There are examples of high-carb foods that are very healthy and examples of carbs that are less-than-healthy. There is room for you to enjoy both; all carbs are not the same.
Myth #3: White carbs are baaaad
Where that myth came from:
White carbs get a bad rap because refined foods with less nutritional value typically fall into this category. Think white bread, white pasta, and potato chips.
The color of the food doesn’t make it bad. Sadly, white carbs get a bad rap, when they can actually be good for you. Sure, white grain products don’t offer as many nutrients as their whole-grain counterparts, but that doesn’t mean they’re bad!
Side note: no food is inherently good or bad, and all foods can be a part of a well-balanced diet.
And sometimes, your lifestyle might make you prefer a “white” carb over the more complex version. Did you know that white rice is actually preferred by many athletes? In fact, eating white rice after working out can help replenish muscle glycogen stores more quickly than brown rice.
When you enjoy more simple, white carbs, keep portion sizes in mind and pair them with something high in fiber and protein to help control the blood sugar response. For example, a piece of bread with almond butter or hummus.
Did you know that there are many examples of white carbs that are really good for you? Potatoes have a particularly bad reputation but are a great source of fiber, vitamin C, and potassium, especially if you eat the skin.
Greek yogurt is another healthy one that gets its carbs from the sugars found naturally in milk (i.e. lactose). It’s rich in protein and beneficial bacteria known as probiotics.
Ever heard of cauliflower? Yea, it’s white, and yea, it has carbs. Try my Banana Bread Cauliflower Oatmeal for breakfast tomorrow – you won’t regret it. It’s healthy and delicious.
Color has nothing to do with if a food is more or less healthy.
Myth #4: Carbs make you fat
Where that myth came from:
It’s no surprise that people think carbs make you fat. If you used to believe myths 1, 2, and 3 and were under the impression that carbs were just grains, chips, and bonbons, well then yes, it makes sense.
And if you’ve ever heard the insulin-carbohydrate theory, well then, it makes double sense. Carb intake = insulin secretion = fat storage. So, carbs equal fat, right?
Any food can make you fat. True, if you eat lots of refined grains, chips, and bonbons, you’ll probably gain weight and fat. But this has less to do with carbohydrates, and more to do with the source and quantity of those carbs.
We love these types of carb-rich foods and tend to overeat them. They also tend to be high in fat and calories too, and any excess intake of calories, no matter the food source, will lead to weight gain. Plus, these carb sources can be low in fiber and protein, meaning they don’t fill you up and cause the “hanger” soon after. Hunger = more eating = more calories = weight gain.
When it comes to the insulin theory, it makes sense on the surface, but unfortunately is not backed by the research.
When you eat carbs, they are broken down into sugar and absorbed into your bloodstream. This signals the release of insulin. Insulin is like the UPS delivery guy – it brings sugar to the cells like packages and the cells take it to use it for energy. But when the cells have too much sugar, insulin must re-route the delivery and instead bring the sugar to the liver to be stored as glycogen for later use.
What does this have to do with fat? Well, when the cells have enough sugar and the liver’s glycogen storage is full too, there’s only one thing left to do with the excess sugar: fat storage.
Here’s the thing, fat storage isn’t always a bad thing – we need some fat! Regardless, research has demonstrated time and time again that increased insulin levels due to high-carb diets don’t seem to increase fat gain. It’s the excess calories that do, not the carbs. It always comes back to boring old calories.
Carbs aren’t inherently fattening. Excess calorie intake leads to fat gain.
Myth #4: Carbs before bed are bad
Where that myth came from:
There’s a theory that if you had carbs before bed, you don’t have time to burn them. It’s thought that your metabolism basically shuts off when you sleep, meaning you can’t use those carbs and so they must be converted into fat.
To make matters worse, there’s also the hormone issue. Remember your fat-storage hormone, insulin? It’s thought that insulin sensitivity is at its lowest at night, meaning those broken down carbs from your evening meal are less likely to be used as energy and more likely to be stored as fat.
I’m not sure where this “no carbs before bed” rule came from, but there’s no evidence whatsoever to show that your body automatically can’t process carbs past 6, 7, or 8 pm…. or anytime for that matter. Your metabolism is working 24/7. In fact, it’s working while you sleep!
Sure, if you eat large dinners this could lead to weight gain. But this isn’t a carb or carb timing issue, this is a calorie issue. Eating too much of any food at any time of day can result in eating too many calories, and extra calories can get stored as fat.
As for the hormone issue, insulin sensitivity may be lower at night compared to in the morning, but that doesn’t mean it’s impaired. In fact, another hormone also takes a dip throughout the day. Cortisol, your stress hormone, enhances the fat-storing effects of insulin. So, if there’s less cortisol circulating at night, it could mean less fat storage.
Eating carbs before bed won’t cause them to be stored as fat.
Myth #5: Low-Carb is Best
Where that myth came from:
Although people have been following low-carb diets for quite some time now, it wasn’t until Dr. Robert Atkins created the Atkins Diet that this low-carb lifestyle became mainstream.
Fast forward to the 21st century and everyone and their mother is avoiding carbs and following the new extremely low-carbohydrate diet trend known as the “keto diet”. With promises of health miracles and drastic weight loss, it’s no wonder everyone’s jumping on the keto bandwagon.
(If you’re curious about my thoughts on the Keto diet, click here).
This is a tricky one. Yes, low-carb diets can work, and some research supports this. There is evidence that following a low-carb diet may improve some heart health parameters, like blood pressure and cholesterol. But again, following any form of a restricted diet, in general, could produce similar outcomes.
What about weight loss? Can a low-carb diet help you lose weight? Research shows that while low-carb diets tend to yield greater weight loss at first than higher-carb diets, this weight loss usually evens out long-term.
Why? Low-carb dieters tend to see rapid weight loss right away due to loss of water weight. Also, low-carb diets can be hard to sustain long-term, and weight tends to creep back on over time as you become less and less strict with the diet.
If you’ve followed a low-carb diet before and it worked, it makes sense. When you must eliminate or limit so many foods, your overall calorie intake is guaranteed to go down. Think of all the high-carb favorites you had to remove from your diet: pizza, pasta, cookies, packaged snack foods, etc. These foods also come with a high-calorie price tag.
Instead of worrying about carb quantity, it’s more sustainable to focus on carb quality and portion sizes.
Your body feels best when you include complex carbs. Low-carb diets are not sustainable long term.
Myth #7: Fruit is Bad Because It’s High in Carbs
Where that myth came from:
Fruit is high in sugar and fiber, and therefore high in carbs. The main source of carbohydrates in fruit is fructose, which is a simple carb. Wait…simple carbs are in fruit? But I thought simple carbs were bad!
Yup, that’s where the confusion came from.
Fruit is high in sugar, but there’s no need to sound the alarm! Remember, fruit is a source of both simple carbs (fructose) and complex carbs (fiber). Thanks to the high fiber content of fruits, your blood sugar won’t skyrocket and plummet like it would if you took that sugar straight up.
Plus, fruit is an excellent source of other disease-fighting vitamins, minerals, phytochemicals, and antioxidants.
Whenever possible, enjoy fruit in its whole form, as opposed to juice, to get the most fiber. Juice tends to not have any of the fiber (unless you’re blending fruit into juice or a smoothie). P.S. If you’re curious as to whether blending fruits in a smoothie destroys nutrients, I’ve answered this question in this recent blog post (click here)!
Most of us are not even close to having enough fruits or veggies – do not let carb phobia make you miss out on having enough of this nutrition-packed food group.
Myth 8: Carbs are bad because they break down into sugar
Where that myth came from:
This myth is a tiny bit different from the rest because the statement – carbs break down into sugar – is actually true. The myth is the “bad” part.
What we really want to know is, do carbs break down into sugar? The truth is, they actually do break down into sugar…but this isn’t a bad thing, it is just normal digestion and absorption.
With lots of fear-mongering about sugar, folks have twisted basic science and made it seem bad. It isn’t. Whether you’re eating brown rice, an apple, or sourdough toast, the long carbohydrate molecules will be broken down into the smallest parts: sugar.
It is also true to say that proteins break down into amino acids…it isn’t good or bad, it is just how your body breaks down large food molecules into the smaller pieces that it can actually use to provide fuel and building resources to your body.
We feel full for longer when we eat complex carbs that contain fiber. But that doesn’t mean that simple carbs are “bad”. All carbs eventually break down into sugar – that is normal digestion in action.
Bottom Line: Myths and facts about carbohydrates
I’ve laid out the facts about carbohydrates, but what’s the biggest takeaway here? Don’t be fooled by scary carb myths like “no carbs before bed”.
If you’ve been following a low-carb lifestyle and it works for you, then great! Just like there’s no one-size-fits-all approach to nutrition, there’s no one-carb-fits-all approach either.
But if fear of carbs has left you hungry, unfocused, and tired, and you’re ready to bring them back into your life, then have no fear. Carbs in general aren’t bad for you. In fact, many of them are extremely nutritious and very good for you!
You have so many to choose from, beyond grain products like pasta and bread. Instead of agonizing over carb quantity, focus on including quality carbs in your diet. High-carb foods like whole/ancient grains, beans, starchy vegetables, and fruit are good sources of fiber, which helps keep blood sugar levels stable and hanger at bay.
And don’t forget to enjoy a cookie (or two) every once in a while… it does the mind good. 😊
P.S. I talk all about carbs–their health benefits, how to incorporate them into meals for satiety and blood sugar balance, and more–in my new book The Plant-Forward Solution: Reboot Your Diet, Lose Weight & Build Lifelong Health by Eating More Plants & Less Meat, available for pre-order now!
Charlotte, thank you so much for sharing this with the world. Very well written and an interesting read. I’ve shared this on social media to help people pause and check the facts backed by science before/while going crazy about the ketogenic diet.
P.S. Have you written on intermittent fasting. It’s the new craze in my circles here (Nairobi, Kenya) and I’m looking to share from other nutritionists/dietitians/health coaches.
Hi Sharon! Thank you so much for your kind comment. It makes me so happy to hear that this information is being read all over the world! I’m working on a piece on Intermittent Fasting that will be on the blog in less than two weeks! I can’t wait to hear your thoughts on it 🙂 It will also come with a mini downloadable guide. Thanks! Charlotte
Pingback: An open-minded dietitian's thoughts on the keto diet - Shaped by Charlotte