What You Really Need to Know About Carbohydrates, According to a Registered Dietitian
Healthy ways to reduce your carb intake without swearing off your favourite foods.
By Laura Jeha, RD
Carbohydrates get a bad rap. Many people blame them for weight gain and other health complications. While some of the knocks against carbs are valid, it’s important to understand the science behind those claims and the health-related nuances of different types of carbohydrates. Armed with the facts, you can make informed decisions about food choices that are right for you.
What are carbohydrates and why are they important?
Carbohydrates are the main source of fuel that keeps your body running. Carbohydrates, or starches, are long chains of glucose (sugar) molecules that are found in grains, dairy, fruits, vegetables and legumes. These chains break down into individual glucose molecules that are either used immediately by the body’s cells for energy or converted into their storage form, glycogen, to be used later. Together, glucose and glycogen provide about half of all the energy muscles and body tissues need to function, while the other half comes mostly from fat*.
Carbs are crucial to fuel your body’s daily activities. Excessive amounts, however, can result in high levels of circulating glucose in the bloodstream, which can lead to increased fat storage and even the development of chronic diseases over time. Insulin, the hormone responsible for stimulating glucose uptake by body tissues and storing any extra in fat cells, plays an important role in this process. With repeated high carbohydrate intake, the body can become less sensitive, or resistant, to insulin, leading to an overflow of glucose in the bloodstream. This can raise blood sugar and increase the risk of diabetes and heart disease.
So what is “low-carb”?
Eating within a range of 50 to 100 grams of carbohydrates per day, or 26 percent or less of your total calories, is generally considered “low-carb”; Health Canada’s recommended average carbohydrate intake is 45 to 65 percent of total calories (about 200 to 250 grams).
There is evidence that restricting carbohydrate intake, even to moderate levels of 100 to 150 grams per day (27 to 50 percent of total calories), can improve biomarkers like insulin sensitivity and blood pressure. Cutting carbohydrates can also reduce your appetite because, by default, you end up eating more fat and protein, which boost feelings of fullness because they take longer to digest.
Then how many carbohydrates should I eat?
If you’re considering lowering your carbohydrate intake, first determine your individual requirements. Carbohydrate needs vary by activity level, body composition and personal goals, so determine your unique daily calorie target, then base your desired carbohydrate intake on that. For moderate intake, aim for 27 to 50 percent of your daily calories.
If you’re doing a lot of endurance exercise, like training for a marathon or an Ironman race, keep in mind that this may not be the time to restrict carbs. Your body is relying on carbs to be its primary source of fuel, and they are necessary to support increased training and recovery.
When and if you do decide to reduce your carbohydrate intake, make sure you are getting enough protein. Eating adequate protein ensures you get all the essential amino acids your body’s cells, tissues and organs need to function properly. Aim for protein intake on the higher end of the recommended range (10 to 30 percent of total calories per day) if you are eating a moderate amount of carbs.
Eating adequate fibre is equally important, as it’s a type of carbohydrate that your body can’t digest. It’s not absorbed into the bloodstream, so it doesn’t impact blood sugar or count towards calorie intake. Once fibre enters the small intestine, it acts like a mesh web, binding to glucose molecules and slowing their absorption and the speed at which they move through the digestive tract, which creates a more moderate blood sugar spike and a gentler insulin response.
It can be helpful to tally only the carbohydrates that are digested and used for energy, or “net carbs.” To calculate net carbs, subtract the grams of fibre from the total grams of carbohydrates in the food or meal. Basing your carbohydrate intake off net carbs can be a good way to ensure you get plenty of fibre.
Fibre promotes satiety, supports gut health and reduces a food’s impact on blood sugar, but remember that excessive fibre intake can lead to uncomfortable symptoms like bloating, pain and constipation. A good target to aim for is 21 to 25 grams per day for women and 30 to 38 grams for men. If you’re upping your fibre intake, you may also want to do so gradually, spreading it throughout the day and drinking plenty of water to avoid discomfort and keep things moving through the digestive tract.
Which carbs should I focus on?
Think about adding non-starchy vegetables, like leafy greens, cauliflower, broccoli, zucchini and peppers to your diet, and limiting starchier vegetables like potatoes, corn and squash. Also, consider choosing high-fibre whole grains like quinoa, barley and oats as well as legumes over refined white grains, pasta and cereals, where most of the fibre is removed during processing.
Other things to watch are desserts, candies and any sweetened beverages, like soda and fruit juice, as well as sweeteners in coffee and tea, which can all add to your carbohydrate intake. Make your own dressings, dips and sauces when possible so you can have more control over sugar content—the premade stuff often has added sugar, especially those products labelled “low-fat.”
Another thing to look out for are products like candies and ice creams labelled as having low or no sugar. Check the nutrition label on the back of the package and you’ll find that while there may be no or low amounts of added sugar, these items can still contain carbohydrates. There are some sweets that do contain zero grams of carbohydrates, which usually means the addition of calorie-free sugar alcohols. But be careful not to go overboard on these either, as they can have negative effects on digestion, like bloating, gas and diarrhea.
A message from our partner:
Bread lovers, rejoice!
You can enjoy all the bread you want.
Summer’s on its way – and many of us are tweaking our lifestyle choices to feel our best, inside and out, for when the warm weather hits. For some of us, a confidence boost comes hand in hand with dietary changes, like reducing carbs. But let’s face it – no one wants to bid adieu to bread! Luckily, Oroweat KETO bread and tortillas are here, so you can eat the food you love…and feel great, too. Here are 5 reasons to try it:
- It’s got incredible texture and flavour. The bread has that soft texture you know and love. For sandwiches, it stacks up – and it makes for terrific toast, too.
- It’s local. Oroweat KETO is produced close to home in Langley, B.C. and Hamilton, Ontario, for bread lovers across the country .
- It’s got ingredients you can believe in. Oroweat KETO is made with plant-based ingredients and no artificial colour or flavours.
- It’s high fibre. There are 13g of fibre per one tortilla (41g) and 17g of fibre per 2 slices of bread (57g) with net carbs of 6g each.
To view products, visit oroweat.ca or follow @oroweatketoca on Instagram.
I follow a plant-based diet. Can I still reduce my carb intake?
Veg-heads can reap the benefits of reducing carbohydrates, but it can be more challenging for plant-based eaters because important protein sources like beans, grains, dairy, soy milk, tempeh and tofu contain carbohydrates while animal proteins like chicken and fish do not.
For vegans, limiting carbohydrates to a moderate level of 100 to 150 grams per day, or less than 44 percent of calories, is a reasonable goal to meet nutritional needs. Best bets for vegans looking to reduce carbohydrates are to lean on plant-based meat substitutes and soy-based products to up protein, but for both vegans and vegetarians, a large remainder of daily calories will be coming from fat. Consider including plenty of unsaturated fats from nuts, seeds, olives, olive oil and avocados, which can help promote lower cholesterol levels.
You may also want to supplement food intake with an unsweetened, vegan protein powder, as well as B vitamins, vitamin D, omega-3s and iron (which are all found in grains, meat and fish) to meet your daily needs with fewer carbohydrates and no animal protein sources.
Whether you’re predominantly plant-based or a dedicated meat eater, it’s a good idea to seek professional guidance when making dietary changes. Working directly with a registered dietitian or nutritionist can help you strategize your carbohydrate intake so that you meet your body’s needs as well as your health goals.
*Whitney, E. & Rolfes, S. (2011).Understanding Nutrition, Twelfth Edition. Wadsworth Cengage Learning
