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Carb Cycling

STUDENT CONTRIBUTOR: Michael Sheng | Nutrition & Food, Ryerson University

March 2, 2021

When living with diabetes, people tend to fall into the trap of thinking all carbohydrates are bad, but that’s not always true! For more physically active diabetics, carb-cycling may be a great way to manage your diabetes and your training.

What is Carb-Cycling?

Carb-Cycling is a very strict diet often used by bodybuilders and athletes trying to cut body fat, build lean muscle mass, or store carbohydrates for endurance activities such as marathons. This is done by cycling between days with higher carbohydrate intake, usually on high activity workout days, and days with lower carbohydrate intake. Some variations of carb-cycling may also incorporate some days with no carbohydrate intake!

Is Carb-Cycling for Me?

Carb-cycling is often used by high-level athletes in bodybuilding, mixed martial arts, and marathon training, because it helps lower body fat while retaining muscle mass. However, if you’re not competing in an athletic contest, carb-cycling may not be the best decision for long-term, sustainable weight management and diabetes management. Before looking into carb-cycling, try experimenting with other dietary strategies that may help with diabetes management.

Due to potential health complications, it’s important to avoid carb cycling if you are:

  1. Pregnant or breastfeeding

  2. Underweight

  3. Managing or previously managed an eating disorder

Remember, carb-cycling is not a free ticket to over-indulging. It is important to note that such these restricted eating patterns may contribute to disordered eating, mental health challenges and/or diabetes distress.

Carb Cycling & Diabetes Management

Carb-cycling has many benefits for managing diabetes as well. One of these benefits is better blood sugar control. Your pancreas releases the hormone insulin when you have lots of glucose from eating carbohydrates, and the hormone glucagon when you have less carbohydrates. Carb-cycling causes your body to limit insulin production on low carbohydrate days to prevent insulin spikes when not needed, which can help improve insulin sensitivity.

Carb-cycling can also strengthen leptin and ghrelin, hormones that are responsible for regulating appetite, making us feel full or hungry. This may also help you become more aware of your body’s hunger signals, which can help with intuitive eating sustainable weight management and improved mental health.

Carb cycling also gives your body a chance to burn fat for fuel on low carbohydrate days, allowing for weight loss, which may help with diabetes management. This is because carb-cycling makes it easier to put your body into a caloric deficit, giving your body a chance to burn fat for energy, which is digested slower and more energy-dense than carbohydrates, as well as does not cause a spike in blood sugar, altogether leading to weight loss.

What to Eat When Carb-Cycling?

There are many different ways to carb-cycle. One way goes as follows:

  • High carbohydrate intake on days you plan on exercising hard 2-2.5g carbs/lbs of body weight

  • Low carbohydrate intake on days when you’re less active 0.5g carbs/lbs of body weight

  • No carbohydrate intake days sparingly (optional) <30g carbs/day

Another method of carb-cycling involves

  • 2 days high carbohydrate intake on days you’re more active (175-275g/day)

  • 3 low carbohydrate intake on days you’re less active (100-125g/day)

Note that carbohydrates play a vital role in your body, and carb-cycling is NOT meant to be a long-term weight-management strategy. See a physician or dietitian, as this is an extreme diet and is not necessary for most people, and can lead to serious health consequences

Since carb-cycling is a very restrictive diet, if you decide to follow it, it’s important to make sure the foods you do eat are foods that can help with slow, manageable digestion and a lower spike in blood sugar, ultimately helping you feel satiated and manage blood sugar on low carb days. For example:

  1. Choose high-fibre fruits and vegetables.

  2. Opt for low-fat milk, cheese, yogurt, and other dairy products.

  3. Stock up on lots of legumes, including beans, lentils, and peas.

  4. Eat lots of whole grains.

  5. Limit refined grains, added sugars, and highly processed foods.

  6. Choose complex carbohydrate sources such as whole grain starches, oatmeal, and sweet and white potatoes

Risks of carb cycling

While there are benefits to carb-cycling, it’s also important to be aware of the risks associated with extreme diets such as this. Currently, there is no substantial research on long-term effects of carb cycling, as most athletes only do it for short periods of time leading up to competition.

Carbohydrates are a cornerstone in a long-term healthy diet. As such, low carbohydrate days can lead to what’s known as the carb flu, with symptoms such as sleep problems, tiredness, constipation, bloating, and mood issues. These symptoms usually go away after a few days but drinking lots of water and electrolytes can help. Canada’s Food Guide recommends making water your drink of choice, which can help you cover your water needs. For low carbohydrate electrolytes, look to dark, leafy green veggies like spinach and kale, as well as nuts, fruit, and fish.

Carb-cycling is considered an extreme diet, please consult your Physician or Registered Dietitian before making any big dietary changes.

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