So what's the real deal with carbs? Do we actually need them? And how much is too much?
What are carbs?
Carbohydrates, abbreviated either 'carbs' or CHO, are the sugars, starches and fibres found in foods. If you're thinking to yourself: "Wow, that sounds like a really big category!", you're right. Carbs are present in virtually foods with the exception of meats, eggs and certain types of seafood and dairy products. All of your fruits, vegetables and grain products contain carbs.
Right off the bat, this should tell you something: "NO" carb diets are a very, very bad idea. Avoiding all fruits, vegetables and grains all together would mean eliminating virtually all your sources for vitamins and minerals. For the record, this is a very, very bad thing. It's also virtually impossible to do for any significant period of time, so be very weary of any diet advocating a 'no carb' approach.
Yes, carbs are almost everywhere in food- to varying degrees- and that's not accidental! They provide the body with its primary form of energy. When the molecules of sugars and starches are absorbed into the system, they convert into glucose, which is pretty much the main fuel that makes our body go. Glucose is critically important for giving you energy, fuelling your brain and helping you create red blood cells- all processes that allow you to maintain homeostasis, which basically is what keeps you alive. Fibre does not convert to glucose, but both soluble and insoluble fibres play pretty important roles in keeping your digestive tract happy.
In short, carbs are your friend.
So why the movement away from them? Well, carbs are a little misunderstood. You see, when you eat carbs, your body sugar levels increase, often rather quickly since carbs are so easily metabolized by your system. This results in the release of insulin, which your body uses to regulate blood sugars. This is a good thing- a pretty important thing really. Insulin is what keeps your body sugars in balance, and it is also what allows you to store excess energy (in the form of glycogen) into your cells.
Now, I'm not going to bore you with the physiological details, but suffice it to say that the basic premise behind low carb diets is to decrease the amount of insulin that you produce (by avoiding spikes in your blood sugar levels that can be caused by simple carbs), thereby forcing your body to burn fat instead of the stored glycogen (which would be converted back to glucose to be used as energy).
So, that sounds good, right? Burning fat instead of stored reserves of sugars means less fat, right?
Sort of.
Again, let's go back and revisit what carbs are good for: they are your primary source of energy. While they aren't technically essential, since your body can fuel itself from fats and proteins, they are the most effective source of energy and contain the highest percentage of vitamins and minerals.
So depleting carbs= less available energy...which often means less ability to do the things that you need to do in order to make your body work optimally. Headaches, weakness, fatigue, constipation, diarrhea...these are all risks when you go too low on the carb machine. And if you've ever tried to work out when you're feeling any of these symptoms....well, you know how well that goes.
Beyond that, there's an awful lot of fats and proteins in the foods that are 'no carb', and super loading on these fats and proteins can actually cause a fair amount of trouble on their own (more on that later!).
Research does indicate that a low carb diet may help with the initial phase of weight loss, but by one year in, the differentiation between a low carb and a balanced carb diet are negligible.
But, by far the biggest risk when it comes to dramatically reducing carbs is neglecting all those tiny little micronutrients that everyone forgets to talk about: vitamins and minerals. These are critical for just about every function of the human body, and skipping out on them is pretty much the worst idea ever. Unfortunately, research shows that taking a supplement just isn't as effective as taking these in from food sources, so making sure to eat your veggies and fruits is kind of a big deal.
So how many carbs do I need?
Depends on who you ask. The Canadian Food Guide recommends that 45-65% of your caloric intake be comprised of carbs! This means that if you are eating 2000 calories a day (which is a decent ball park average for most people and the 'normal' calorie intake of most food labels), you're looking at 900 to 1300 calories just from your carbs! That's a lot of carbs, particularly when you consider that most basic carbs (fruits, vegetables, and unrefined grains) are actually pretty low calorie compared to your fats and proteins! When it comes to filling up your plate, that's a lot of bang for your buck.
But...
How you get those carbs in...well, there is some wiggle room there.
You see, there are a couple of different types of carbs, and focusing in one some while avoiding the others can be a pretty decent strategy for finding the balance.
Simple carbs are sugars. Most are comprised of just one or two sugar molecules, which means that they are very quickly absorbed and digested. This group, which includes table sugar, molasses, honey, and fruit juices, is not so necessary for your functioning- that is, unless you need a quick intake of sugar, as soon as possible (which may be the case for people in insulin shock). Many people refer to these types of carbs as 'empty calories', because their nutritional value is low for the amount of calories that they deliver.
In short, if you want to lower your carb intake, start there.
Note: Most fruit is technically considered a simple carb, but because of the awesome amount of fibre and micronutrients, we don't consider fruit to be 'empty calories'. Fruit is generally a healthy, albeit high in sugar, choice.
Beyond this, many people choose to limit their grain intake. Again, this can be a little risky in terms of ensuring that you are getting all your vitamins, minerals, and fibre intake- grains are excellent sources for these- but it is doable to get by primarily on plant sources of carbs. What you need to remember is that plant sources are significantly lower in carb count than grains are. So, if you are going to go grain free, look for high carb plant sources like starchy vegetables (squashes, potatoes, sweet potatoes, beans, legumes) and high fibre vegetables, including cucumbers, broccoli, asparagus and peas. Make sure you get a variety of vegetables and fruits onto your daily plate so that you hit all those key nutritional needs above and beyond your calorie count.
And remember, you're going to need an awful lot of vegetables and fruits to get your daily carb requirements compared to grain or simple carb sources. So take the time to really do the math and understand what your actual dietary needs are before cutting the additional sources out.
But wait- if 45-65% of my diet should be carb based...why do I hear about protein all the time?
That, friends, is a question for my next post.
As always, my best advice for those who are seeking to make radical dietary changes is talk to a professional! A nutritionist, dietician or health care provider should be your number one stop for all questions diet related!
