There is a lot of confusion around carbs. And it comes at no surprise since the sugar industry single handedly demonized fat by paying scientists to play down the harmful effects of sugar in the 1960s. A great article to read detailing the events of this can be read here. There are many people that think fat is bad still and that it is the cause of cardiovascular disease and obesity, among other things. I still hear people say to avoid animal fat and that the saturated fat in dairy and meat causes cardiovascular disease, when in fact there is little correlation (1). I will get to all that in another post though.
What are Carbs?
I’ll save you the chemistry talk and get right to the practical stuff. Unlike protein and fat, which have multiple uses in the body, carbohydrates have one primary use and that is for energy. If one eats too many carbs for the given day's activities, then the extra energy is converted to fat and stored for later. This is very advantageous for survival from an ancestral standpoint, however, we now have a lot more food at our fingertips. When we are sitting, walking, sleeping or doing other low intensity activities, we are using predominantly fat for energy. If one is quite sedentary, which is the vast majority of people, especially those who sit at a desk for work, then not many carbs are required by the body and one should stick to a lower carb, higher fat diet. Merely going to the gym a few times a week for an hour doesn’t tip the scale much in your favour of requiring more carbs either.
If you like eating carbs, which many, many people do, myself included, then you must earn them. The first step is to just start moving more, if you are currently mostly sedentary. Try walking at lunch or after work or instead of laying on the couch at night, stretch on the floor or try getting up from your desk every hour to walk around your building or climb a few sets of stairs. As mentioned, you will still be burning primarily fat doing these activities, but it is a place to start. If you really want to earn your carbs, do an activity that gets your heart rate up and gets you out of breath. Health Canada recommends at least 150 minutes of moderate to vigorous physical activity per week in 10 minute bouts or more. It is very satisfying to eat after exercising vigorously knowing that you’ve earned your carbs and rest.
Types of Carbs - Starch, Sugar and Fibre
Starch is the most commonly consumed carb and is comprised of a number of glucose molecules. When consumed, the glucose molecules are broken apart and absorbed by the intestine into the portal vein, which goes straight to the liver. The liver helps regulate blood sugar and after a big meal, the pancreas will release insulin to help regulate blood sugar as well. Insulin's job is to signal to our cells to put out glucose receptors in order to take in glucose from the blood. Our blood sugar needs to be tightly regulated because glucose is the preferred fuel source for red blood cells and the brain.
Common food sources of starch include: wheat and wheat products (pasta, baked goods, bread, tortillas), root vegetables, bananas, chickpeas, lentils, beans, rye, rice, oats, barley and buckwheat.
Sugar is also a commonly consumed carb. What’s important to remember about sugar is that when it's consumed in foods such as fruit and vegetables, it is bound in a fibre matrix. This creates a slower release of sugar molecules into the blood, preventing a large insulin spike, not to mention all the phytochemicals, vitamins and minerals. When it is consumed in a beverage (pop, iced tea, juice and even 100% pure juice) or food product with added sugar, the sugar molecules are on their own (monosaccharide form), unbound and therefore are absorbed by the intestine very quickly.
Fruit is the healthiest way to eat sugar. As mentioned, the sugar is bound in a fibre matrix and fruit also contains a lot of water, both of which increase satiety and deter you from over consumption. Naturally occurring sugars in fruit are beneficial to health and do not promote weight gain. Some studies suggest that eating whole fruit may actually decrease the risk of diabetes and obesity. So, grab an apple, banana or cup of blueberries the next time you are craving sugar and do your body some good!
Sugar is snuck into all kinds of products. In fact, ⅔ of all packaged products in Canada have added sugar. “Low fat” products are notorious for adding more sugar, which is a double whammy since they took out the fat (which is good for you). I highly suggest avoiding low fat or fat free dairy products. The type of fat in dairy (long chain fatty acids) is really important for the structure of our cells and comprises 75-80% of fatty acids in most cells. When you remove or reduce the fat, you are left with mostly lactose. On top of that, food companies will usually add more sugar to these products to improve the taste in the absence of fat.
Here is a list of words used by food companies to list sugar in their ingredients. I suggest eating foods with these added sugars only in moderation, just a handful of time per week or less: anhydrous dextrose, cane sugar, corn syrup, corn syrup solids, liquid fructose, dextrose, evaporated cane juice, fruit juice concentrates, molasses, carbitol, diglycerides, disaccharides, fructooligosaccharides, galactose, glucitol, hexitol, isomalt, maltodextrin, malted barley, nectars, rice syrup, sorghum and anything ending in syrup, (pure maple syrup is okay).
Fibre is the lesser consumed carb of the bunch, which is a shame because it promotes gut health and also doesn’t contribute to our daily caloric intake as it is not absorbed in the intestine. Fibre also is very satiating, which can be helpful for people trying to lose weight or maintain a healthy weight. Fibre is really important for the gut microbiome as it feeds our good bacteria, which has many total body implications discussed at further length here.
One of the main reasons why processed foods are so bad for us is they have been taken away from their natural state and made into something else. They have also been partially digested for us (the breakdown part has been done already), so it take less time and energy for us to digest them, which spikes our insulin. When you eat a piece of white bread, it has had its vitamins, minerals, and fibre stripped away and then some are added back. Seems like extra work to make a product that is not as good for you. When you eat vitamins and minerals in food, you are also eating certain enzymes, co-factors and mineral activators that help the absorption and utilization of these nutrients. However, when you strip them away, as in the case of white bread and all other refined grain products, and then just add the vitamins and minerals back, you are missing other integral components.
If you eat grain products like wheat, rye, barley, oats and rice, then try to eat them as close to their natural state as possible. Eat whole grain products, not just whole wheat. Whole wheat is still refined. You should be able to see bits of grains, in your bread, or tortilla, for example. Quinoa and rice, for example, are whole grains in and of themselves, so they are fine (if you’re metabolically healthy). Try to limit products with refined grains to once or twice a week. This includes many, many products such as bread products, tortillas, pizza dough, cookies, doughnuts, pasta, cereals, fruit bars, breaded chicken, cake and other baked goods.
Tips to remember
- Earn your carbs - try to get your heart rate up every day.
- If you are mostly sedentary (work from a desk and don’t get your heart rate up daily) then try to stick to a lower carb, higher fat diet. Need help determining what that looks like for you? Contact me at firstname.lastname@example.org.
- Eat fruit, veggies and sweeten your food with natural sweeteners (maple syrup and honey) instead of consuming sugary treats and beverages.
- Stay away from added sugars. Get in the habit of checking ingredient lists before you buy something. Keep an eye out for those sugar-in-disguise words I mentioned above in the sugar section.
- Eat whole grains and remember whole wheat is not the same as whole grain. Limit processed grain products to once or twice a week. This can be tricky for those who are currently consuming a few per day, so just take small steps. Cut down to one or two per day, then one per day, then one every other day, etc. Making an effort will absolutely pay off in how you feel and will likely help you lose a few pounds. Remember that it is a process, and all that matters is that you are making small changes to build healthier habits.
1. Siri-Tarino, P.W., Sun, Q., Hu, F.B. & Krauss, R.M. (2010). Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease. Am J Clin Nutr, 91(3), 535-46.