Good carbs, bad carbs, high carb diet, low carb diet, carbohydrates (and people’s opinions about them) are everywhere. There are nearly countless ways to refer to them, making it a confusing nutritional landscape for the average person. What needs to be answered first is what is a carbohydrate?
Carbohydrates is the general term for hundreds of molecules that have repetitions of the base molecules C and H2O (C-arbon connected to H2O-drate), generally with 5 or 6 carbons. These are arranged in several structures including aldehydes and ketones; what we’re really focusing on here are the ones that are arranged into a ring structure to form the most basic form of dietary carbs known as sugars (or saccharides). We tend to think of sugar as the white crystalline substance that is replaced with salt on April Fool’s Day, but there are thousands of types of sugars in the natural world. Sugars often exist as monosaccharides (one sugar molecule) or disaccharides (two sugars linked).They are also frequently linked together to make chains known as polysaccharides (aka multiple sugars, aka starches and fibres). These chains can have just one or multiple types of sugars, they can be short, medium, or long, they can be straight or branched, they can have digestible and indigestible bonds. So “carbohydrate” can refer to any molecule in this family, be it a sugar or any type of starch or fibre.
Within the human body, sugars act differently than oligosaccharides (short chains of sugars), and both act differently than starches; fibres are a different story all together. Dietarily speaking, there is an obvious difference between these molecules. Sugars, like table sugar, maple syrup, and honey all fall into the category commonly known as “simple sugars”, meaning these foods are pretty much only mono- and di-saccharides. The term “complex carb” is a little more nebulous and open to interpretation, but it includes long-chain starches that may or may not have fibres accompanying the starch; whole grains like brown rice and starchy tubers like sweet potatoes fall into this category. “Simple carbs” or “refined carbs” generally refers to starches that have been altered from their natural state, typically by removing the fibres and or reducing the length of the starch chain; think white flour, starchy thickening ingredients, processed potato foods.
Given that carbohydrates is such a broad category of substances, it is unfair to paint them all with the same brush, either saying they are all good or all bad. As with most areas of life, it is the nuance and the choices within the category that are most important. Humans, among most life forms, use carbohydrates for energy production. Sugars, more specifically free or added sugars, are proving to be significant contributors to many chronic diseases and should be limited. As delicious as they are, these carbs by and large bring very little to the table other than calories. They are absorbed and digested very rapidly so they provide only quick, not lasting energy; they cause significant fluctuations in blood sugar levels. This applies whether you like plain old white sugar, only the purest Quebec maple syrup, or organic non-gmo fair-trade coconut sugar: sugar is sugar is sugar. I do want to note that sugars that occur WITHIN a whole, minimally processed food do not necessarily fall into this category. For these foods: a) the sugar is typically in a much lower concentrations b) It is often accompanied by fibres that help slow absorption and digestion and c) you’ll be eating some variety of vitamins, minerals, phytochemicals, fats, starches, and proteins along with the sugars.
As for starches, high fibre and minimally processed varieties are the way to go. These foods tend to have much longer starch molecules (meaning they take longer to break down) as well as dietary fibres, vitamins, and minerals. A good rule of thumb is that the more a food resembles its original form, the more nutrition and health benefits it brings. So, selling features like “pre-made”, “instant”, or “just add water” are very good indicators that the carbohydrates within that food are fairly heavily processed. These more “simple carbs” are starches that are digested more rapidly and have more similar effects to sugars. Diets high in this type of carbohydrate tend to increase the risks of developing chronic diseases compared to less refined carbohydrates.
But don’t carbs make us fat? No. Well, not in and of themselves, necessarily. Let us always remember that the dose makes the poison. As I’ve said, we should not judge all carbohydrates equally. A balanced diet with moderate consumption of high fibre carbohydrates is much less likely to lead to poor weight management. This is because fibrous foods are far more filling and satiating than refined carbs. Now an unbalanced diet, even heavy in whole grains and starches, may lead to weight issues. Some nutrients like protein and fat cause chemical signals in the human body to trigger fullness and satiety. Carbohydrates do not; humans will continue to eat carbs until we are physically full. While fibre does not chemically trigger satiety, it is far more filling than starches, so it will encourage smaller intake. So, if your diet is low in protein, fat, and or veggies and fruits (low calorie foods), and very high in starchy foods, chances are you’ll eat more calories because it takes more food to feel full. Diets high in sugars and processed starches make this even more likely.
But aren’t starchy and sweet foods bad because our ancient ancestors didn’t consume them? No. Homo sapiens are an ingenious, omnivorous species that has eaten whatever we could get our hands on right from the start. The concentrated energy of starchy foods helped us advance and grow the wrinkly gray masses in our heads to the sophisticated and complex brains we enjoy today. Even if it was true, it’s a fallacy to assume that we should never change our diets or lifestyles as it’s clear that the human species continues to evole, it didn’t stop 10,000 year ago. If we are going to follow this logic, then we should all ditch our cars and air conditioning and mobile devices in favor walking, sweating, and yelling all the time because our ancient ancestors didn’t use these things either.
So go ahead, enjoy some carbs. Choose whole, filling, fiberful carbohydrate sources most of the time. Balance meals with proteins and as many vegetables as you can get your hands on. And when you do occasionally eat cake (because life is better with cake), savour your piece and don’t worry about all the sugar and refined flour. You’ll be fine.