Carbs get a bad rap. We’re taught that carb-heavy foods should be avoided, but the reality is that carbohydrates are essential to a balanced diet. About 45 per cent to 65 per cent of our daily kilojoules should come from carbohydrates. Some are usually called “good” and others “bad,” because not all carbs are created equally when it comes to your nutrition. It helps to understand why some carbs are less healthy than others, because you shouldn’t swear off the category entirely.
Part of the reason there’s a rising obesity epidemic in Australia is due to overconsumption of refined carbohydrates, such as cakes, muffins and confectionary. “We should fill half of our plate with fruits and vegetables, then a fourth on some kind of lean protein, and then limit those carbohydrate choices to the other fourth of our plate,” explains dietitian Julie Smith.
What are refined carbs?
Refined carbohydrates are sugars and starches that have been altered in the process of turning them into packaged foods. They originally come from natural whole grains but are heavily processed to remove the outer shell and seed portion of the grain. After milling the grain, you’re left with better flavoured carbohydrates—and food with a longer shelf life.
Stripping parts of the grain also removes almost all essential vitamins, nutrients, and dietary fibre. “The outer portion is actually what gives our body all the nutrition that grains give us and all the fibre, so they processed it to take that away,” says Smith.
You can find refined carbohydrates in white bread, pizza dough, cornflakes, and white rice.
What’s the difference between complex carbs and refined carbs?
If refined carbohydrates are the “bad” carbs, complex carbohydrates are the “good carbs.” Complex carbohydrates provide nutrients and fibre that the body needs to sustain itself.
“We should make sure that at least half of our carbohydrates are complex carbs, such as whole grain and sweet potato, and really try to limit those refined carbs to 50 per cent of our total carbohydrates for the day,” says Smith. You can find complex carbohydrates in oatmeal, whole grain bread, sweet potatoes, and brown rice.
Why should refined carbs be limited?
Refined carbs do little to keep your body running smoothly.
You’ll miss out on essential nutrients
Whole grains and other complex carbs are a rich source of vitamins and minerals. These may include:
- B vitamins: Maintain healthy brain activity and cell function
- Iron: Helps red blood cells carry oxygen from the lungs to the rest of the body
- Fibre: Helps with digestion and keeps you satiated
- Potassium: Regulates blood pressure, and supports muscle and nerve activity
- Magnesium: Helps support muscle and nerve activity as well and helps convert nutrients from food into energy
- Folate: Also known as vitamin B9, eliminates an amino acid called homocysteine that at high levels can harm the body
- Selenium: A mineral that protects against cell damage
You’re more likely to have digestive problems
Your gut bacteria depends on fibre for fuel. Without fibre to feed on, your gut microbiome loses its diversity as all sorts of bacteria, including the ones that promote good health in your body, die off.
Fibre in whole-grain cereals or pasta can also promote healthy bowel movements and relieve constipation.
Avoiding refined carbs can help keep chronic diseases at bay
A diet high in refined carbs is associated with:
- Type 2 diabetes
- Heart disease
- Early death
- Obesity
- Poor metabolic health
- Fatigue
- Increased cholesterol
Benefits of healthy (complex) carbs
You’ll feel full without overeating
Since refined carbohydrates remove fibre, they do not make you as full as whole grain foods—eating lots of refined carbs can lead to overeating. “Oatmeal or a slice of whole grain bread has complex carbohydrates that take longer for the body to digest and will keep you full until your next meal,” says Smalling. Fibre also releases a chemical called acetate that sends a message to your brain of your satiety.
If you’re looking for a snack between meals, Smalling recommends fruit or veggie slices. They both have complex carbohydrates and are rich in fibre.
Maintains consistent blood sugar levels
All carbohydrates are made up of sugar, but it’s the chemical structure between refined and complex that makes the difference. Refined carbohydrates have only one sugar molecule, while complex carbs have long chains of sugar molecules. The body breaks down both types of carbohydrates and converts them into glucose for energy. However, Smalling says breaking a long chain of sugar takes time, raising blood sugar but at a slow and steady pace.
Keeps your brain running
Your brain runs on carbs—more specifically, the nutrients in the carbohydrates. Magnesium and potassium help neurons send messages to brain cells via electrical activity. Magnesium also helps overexcited neurons frequently firing signals to calm down, bringing it back to a resting state. “Your nerve cells’ first choice for energy is carbohydrates. Why would you want to deprive your brain and nerves from the energy they need?” explains Smalling.
How to choose complex carbs
Both experts agree that reading food labels is the best way to pick foods high in complex carbohydrates. You’ll want to pay special attention to fibre content. In Australia, there are some cases where adding particular vitamins or minerals to food is mandatory. For example, folic acid must be added to wheat flour in bread products. In other cases, like with cereal, certain vitamins or mineral may be voluntarily included like zinc, iron, calcium, omega-3, vitamin D and Thiamine (vitamin B1). Fibre is easily removed during the milling process when it comes to cereal and white bread, but cannot be directly added back in unless it is in the form of resistant starch, which isn't as beneficial. Smalling explains that this is one of the main nutrients that we end up losing. Even if a whole-grain product like brown rice only has a few grams of fibre, it is still better than white rice, which has even less.
The bottom line: Carbs are an important part of any healthy diet, and dietitians agree that complex carbs are better for you than refined carbs. If you feel you may need to adjust your diet for more energy or better overall health, consider consulting a nutritionist. They can help set up a nutrition plan that works best for you.
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