The Lowdown on the Low-Carb Diet

The Lowdown on the Low-Carb Diet

If you’re reading this, chances are you hear or read about carbohydrates at least once a week. Right? Good, bad, high-carb, low-carb, complex carbs, simple carbs. If you feel overwhelmed, you’re not alone! 

There’s so much information about carbohydrates, yet so little clarity. But, low-carb eating is having a moment in the spotlight. So, we’ll give you the lowdown on low-carbohydrates. 

What’s a Low-Carb Diet?

Let’s rewind a bit. There are three primary macronutrients; carbohydrates, protein, and fat. Carbohydrates are your body’s main source of glucose – your most vital energy source.  

You need glucose to survive and thrive. When you think of foods that have carbohydrates, you likely jump to the classics: white bread, white pasta, white rice, and you’d be right. But you’ll find carbs in fruits, starchy vegetables, legumes, beans, whole grains, and dairy products also. They’re almost everywhere; it’s nearly impossible for you to eliminate carbs. So what does low-carbohydrate eating mean, exactly? 

Your recommended daily macronutrient ranges for an average adult are: 

How to Classify Low-Carb Foods
  • Carbohydrates: 45-65% of your daily consumption – 225-325g 
  • Fat: 20-35% of your daily consumption – 45-75g fat
  • Protein: 10-35% of your daily consumption – 50-175g 

The regular eating plan suggests you eat less than 225-325g of carbs per day. There are a plethora of  low-carb eating plans and no consensus on how many carbohydrates are optimal, but most studies and health providers define “low-carb” as 120-150g of carbs per day and “very low-carb” as 20-50g of carbs per day. Before you go 100% restriction mode – “I must cut out all fruit, grains, and beans!”, take a breather and recognize the words “low-carb” for what they are – low in carbs, not no carbs. However, if you eat 130-150g daily, it’s far less than the typical Western diet, so if you want to try a low-carb eating plan, we’ve got the info you need! 

Should You Eat Less Carbs?  

Weight Loss 

If you’re seeking weight loss, you may benefit from a low-carb eating plan. Reducing your carb intake can help you lose weight for up to one year. When you compare low-carb eating to the low-fat craze from the ‘70s and ‘80s, it seems a useful option for weight loss. However, there appears to be an expiration date of 12 and 24 months on its benefits. A review of 17 studies found those who followed a low-carb diet lost more weight than individuals on a low-fat diet, but the difference slowly decreased after 12 months. Another 12-month weight loss study of over 600 adults found individuals on a low-carb eating plan and those on low-fat diets lost similar amounts of weight.

 So, what’s the main message? It’s all about compliance! If you want to lose weight and reduce carbs fit into your lifestyle, then go for it. It can be effective and has proven benefits. You may also experience reduced hunger because you’ll likely be eating more protein and fat, which are slower-digesting nutrients that keep you full for longer. 

Type 2 Diabetes

If you’re living with type 2 diabetes, lowering carbs may reduce your A1c, regardless of weight loss. A1c is your average blood sugar level over three months. It may also improve your triglyceride levels and may be as effective as insulin therapy. However, short-term studies and the long-term impact of reducing carbs on blood sugars and diabetes are yet to be determined. If you’re considering adopting a low-carb diet, speak to your doctor or Registered Dietitian for more individualized information and support. 

Risks of a Low-Carb Diet

If you’re worried about reducing your body’s primary source of glucose, don’t fret. Even if you eliminate carbs, your body will derive glucose from protein and fat through a process called metabolic adaptation. 

Poor Digestion

Whole grains, legumes, vegetables, and fruit are terrific sources of fiber. Fiber is a non-digestible carbohydrate that regulates your bowel movements and ensures your trip to the washroom is a comfortable experience. Adult females require a minimum of 25g per day, while adult males require at least 38g per day.  

Restricting carb-rich foods may subsequently reduce your total intake of fiber, which increases your risk for bloating and constipation. Lack of fiber also starves your microbiome, which adversely affects your digestion. To ensure you’re reaching your fiber targets, fill your bowl or plate with vegetables like broccoli, bell peppers, cooked spinach, nuts (almond, peanuts, walnuts), and seeds (ground flax, chia, pumpkin seeds). You must stay hydrated – it will help you prevent constipation and poor digestion. 

Disordered Eating

A healthy relationship with food always comes first. While seemingly innocent, counting macronutrients may instill a “fear of carbs” and increase your risk for an eating  disorder. If you struggle with body image, control around food, or have an eating disorder eating behaviors in the present or past, you may want to avoid eating low-carbs. 

Heart Health

It seems the jury’s still out on how low-carb eating affects your heart health. Two significant studies don’t agree whether low-carb eating can be fatal: While one study shows a correlation between a shorter lifespan and eating less than 40% of your total calories as carbs, another says there’s a link between high carb intake and an increased risk of fatality. Also, the studies didn’t show beneficial or adverse effects on heart disease. 

When research offers conflicting information, it can be challenging for you to choose the best route to take. Your best bet is always to listen to your body: It will let you know if you need more or fewer carbohydrates.

Knowing How to Classify Low-Carb Foods

Follow these steps a few times to learn which foods are low-carb. After you count your carbohydrates a few times, you’ll have an idea of how your carbs add up and can follow your instincts. Don’t feel like you need to count your carbohydrates forever, it’s too much work and not sustainable.

  1. Find the nutrition information of a specific food 
  2. Subtract the fiber from the total carbohydrates; this is your net carbohydrates. 

A good rule of thumb aims for 30-45g of carbs per meal and 15g per snack. If you are looking to eat “very low carb,” aim for 15-30g per meal and 10 per snack. 

For example, one slice of sprouted grain bread = 15g carbs, 3g fiber. The net carbs would be 12g. On its own, this food is a “low carb” food. 

However, when you eat two slices (24g net carbs), add 2 tbsp jam (28g net carbs), and an apple (20g net carbs), this increases to 72g of carbs; a high-carb meal. 

Remember, you only need to do this a few times to get a sense of which foods are low-carb. Counting carbs at each meal is exhausting and unsustainable.

A good rule of thumb is to focus on leafy greens, seafood, dairy, fruit, and moderate amounts of whole grains and beans/legumes. Practice mindful eating while enjoying your low-carb meal. Slow down, chew thoroughly, enjoy the flavours. 

List of Low-Carb Foods:

Vegetables 

  • Green, leafy vegetables (spinach, kale, arugula, Swiss chard, bok choy, mustard greens, collard greens, alfalfa sprouts)
  • Cruciferous vegetables (broccoli, cauliflower, Brussels sprouts, cabbage)
  • Bell peppers
  • Mushrooms
  • Eggplant
  • Carrots, celery
  • Okra
  • Spaghetti squash
  • Zucchini
  • Rhubarb

Fruit

  • Avocado
  • Tomato
  • Strawberries, raspberries, blueberries, blackberries, cranberries
  • Rhubarb
  • Lemon, lime
  • Olives

Seafood, Meat, Dairy

  • Eggs, yogurt, milk, cheese
  • Salmon, tuna, mackerel, halibut, sardines
  • Shrimp, scallops, crab, lobster, mussels, oysters, clams
  • Chicken, beef, pork, lamb
  • Edamame, tofu, tempeh, soy nuts, soy milk

Nuts, Seeds, Oils

  • Pumpkin seeds, sunflower seeds
  • Chia seeds, ground flax seeds, hemp seeds
  • Almonds, walnuts, cashews, pistachios, peanuts, pecans, pine nuts
  • Nut and seed butter
  • Olive oil
  • Avocado oil

Should You Go Low-Carb? 

The low-carb diet is effective for weight loss and reducing hunger. If you follow a low carb diet, you may find it easier to naturally focus on higher-quality carbs and eliminate refined, ultra-processed foods. It’s all about what works best for you. 

You can start by incorporating more low-carb foods into your day and eliminate refined carbs like white pasta, white bread, and desserts. Also, try some new low-carb recipes to diversify your eating plan. From there, you can incrementally decrease your carb intake and find what works best for you.

Click here for a comprehensive list of low-carb foods!

Author's bio

Trista Chan, RD, MHSc

Trista Chan, RD, MHSc

Trista is a Registered Dietitian with her Master of Health Science in Nutrition Communication at Ryerson University, Toronto, and holds an Applied Human Nutrition degree and a graduate certificate in Workplace Wellness. Trista has diverse work experience in organizations both big and small. ...