It’s time for some science!🤓
Today we’re talking about my favourite nutrition villain…(insert ominous music)…carbohydrates!
Why are carbs my favourite nutrition villain? Glad you asked. I love carbs because A. They’re delicious and B. They can be terribly misunderstood. I love to share nutrition facts with you and clear up misconceptions, and when it comes to carbs there are plenty!
What are carbohydrates (or carbs for short)? Is there such thing as good carbs and bad carbs? How many carb can I eat in a day? Will Carbs make me gain weight?
First, I’m going to share a story with you about how poorly carbohydrates are understood- even by people who are providing nutrition advice (you can read more about my thoughts on non-regulated nutritionists here). Earlier this week, during a nutrition counseling appointment, a client I’ve been working with told me a few “healthy eating tips” her personal trainer gave her. Her trainer told her not to eat fruit or a granola bar before working out because they’re too high in sugar, but that she should eat carbs instead, like half a bagel. If you aren’t too sure what exactly is so funny about this, then read on!
Carbohydrates = Sugar…Literally
The term “carbohydrate” is simply the chemical term for sugar. They are molecules made of various combinations of Carbon, Hydrogen, and Oxygen which our bodies are able to break down for energy. Carbohydrate is a huge umbrella term that encompasses ALL the different variations out there. Within the category of carbohydrates there are 3 main groups. Simple Sugars, Complex Carbohydrates (aka Starches), and Fibre.
For example, here is how glucose is structured… This is the simplest form of sugar, called a monosaccharide.
Simple Sugars are just that…simple structures made up of only 1 or 2 sugar molecules. The single sugars (monosaccharides) are Glucose, Fructose, and Galactose. The various combinations of 2-sugar molecules (disaccharides) are made from these. Simple sugars are found in foods that taste sweet such as fruit, white sugar, brown sugar, milk, honey, agave, etc. These types of sugars are very quickly broken down and absorbed by our bodies for energy because there isn’t much to them. They are less “filling” than other carbohydrates because they don’t take much time for us to metabolize them.
Complex carbohydrates, or starches, are larger, longer chains of these simple sugars bonded together (polysaccharides). They vary by their look and structure but the main components are the same. These types of carbohydrates take a bit longer for our bodies to break down. Enzymes in our bodies need to break every single bond in the chain before the individual sugar molecules can enter our blood stream. This is why starches/complex carbohydrates don’t taste as sweet to us, and fill us up for longer.
This is the structure of a starch molecule
What’s important to note however, is that all of these are digested and absorbed by our bodies by the SAME mechanisms. Sugar is sugar is sugar. We use the same enzymes and transporters to digest bread, fruit, white sugar, milk, and all of the other hundreds of food items that contain carbohydrates. Once they’re in our gut, our bodies treat them all equally (read on to find out what ELSE is in our foods might make some better than others)
Fibre, on the other hand is a bit different from simple sugars and starches. We actually do not get any calories from fibre (we lack the enzyme needed to digest it), but that does not mean that it doesn’t play an important role in our health. Two types of fibre is found in our foods- soluble and insoluble. Soluble fibre (found in oats, fruits, and supplements like metmucil) act as a gel in our digestive tract. It slows down how quickly our digested food travels through our intestines, which keeps us from feeling hungry as soon after eating. Insoluble fibre (like wheat bran or flax) add bulk to our diets, and fill us up without adding additional calories to our diet. Insoluble fibre also helps to keep our bowl movements regular. Both types of fibre are important for good health, and one of the reasons we encourage consumption of whole fruits and vegetables (juice does not contain fibre) and whole grains.
So, are there good and bad carbohydrates? Not so much… there are definitely some carbohydrate-containing foods that are better than others, because they offer us other nutrients aside from just calories. Compare for example, two slices of whole wheat bread, and about 10 fuzzy peaches candies. Both have the same amount of carbohydrate, and similar calories, but one is OBVIOUSLY more nutritious than the other….why?
It’s because the whole wheat bread gives us more than just the sugar, more than just the calories. Whole grains have fibre, vitamins, minerals, and protein too. The candy is what we refer to as ’empty calories’. It contains no additional nutrients, just sugar. Even though our bodies metabolize all sugars in the same way, it’s what other benefits a food can provide that make it a good choice vs a not-so-nutritious one.
So, how much sugar should we be consuming in a day?
Well, for all carbohydrates (including simple sugars and starches), 45-65% of our daily calories should be coming from carbs. It’s a pretty big range, so I choose the exact target for my clients based on how active they are. Think of carbohydrates in your diet like gas in your car. The more driving you do, the more gas you use. Most of the carbohydrates we eat in a day should be from nutritious sources, such as fruit, milk, yogurt, whole grains, and starchy vegetables. We want to limit the “empty calories” we get from things like fruit juice, pop, or candy. For women, we should be limiting our added sugars to no more than 6 tsp (24 grams, or about 100 calories) per day. For men, the limit is 9 tsp (36 grams, or about 150 calories)
A lot of low carbohydrate diet pushers talk about minimizing carbohydrate intake to reduce insulin production, because insulin makes us gain weight. If we kept insulin levels in our bodies to a minimum, we’d be home free from weight gain forever.
Ooookaaay, now this is a classic example of extrapolation of evidence and “bro science”. Yes, insulin is a hormone that plays a role in glucose metabolism, by which it allows sugars to enter our bodies cells to either be stored, or used for energy. But insulin itself does NOT CAUSE WEIGHT GAIN. Our bodies automatically adjust insulin levels to match blood sugar levels and keep them stable. If we’re gaining weight, it isn’t insulin’s fault- it’s that were taking in more calories than our bodies’ truly need, and we’re storing the extra energy as fat.
So, carbohydrates aren’t so bad after all! They keep our bodies fueled and energized. without them we can feel fatigued, have trouble with memory, cognition, and mood. Eating the RIGHT amount of carbohydrates for your activity level, and choosing carbohydrates sources that provide you with the most overall nutrition is key for good health.
And is butter a carb? NOPE. Butter is a fat. We can talk about that later.
Have questions about carbs and the right amount for you? Contact me!