Nicole Moore (Master Nutr. APD)

4 steps to finding your carbohydrate tolerance

3 mins read

It’s important that if you have pre-diabetes or type 2 diabetes, you understand your carbohydrate tolerance or threshold.  Carb tolerance is simply the carbs you can have before your blood glucose levels increase. Many patients ask how many carbohydrates they will be able to eat in the long term to keep their blood glucose in a healthy range and keep their weight stable if they’ve achieved weight loss.

My answer is simple: everyone is very different. Everyone will tolerate a different amount of carbohydrates and have different carb thresholds or tolerance. So, how do we establish what our threshold is?

How to calculate carbohydrate tolerance

“Tolerance level” is the amount of carbohydrates you can eat before your blood glucose levels start to rise. If you overindulge in carbs (as we often all once did), you might also experience other symptoms such as tiredness, hunger and fogginess.

Some people can tolerate 50 grams of carbohydrates per day (such as a bowl of spaghetti). Others may tolerate up to 100 grams per day (think two sandwiches or a large portion of rice). Yet others may only be able to consume 25 grams of carbohydrates per day (such as half a burger bun).

It’s important to work out your own carb tolerance level. How much carbohydrate can you eat each before it starts impacting your health,  you gain weight and your blood glucose rises? Four simple steps will help you do your very own carb tolerance test:

  1. How many carbs do you eat? The first thing to do is work out how much total carbohydrate you eat. We do this by calculating the average total carbohydrates in all the foods and fluids you eat daily. You need to become a carbohydrate detective! You could try using an app like My Fitness Pal or Carb Manager.
  2. Work out your average fasting blood glucose level: Next, measure your fasting blood glucose in the morning before you start eating for the day. Measure this every day for a week to determine your average fasting blood glucose levels. Next, I suggest you follow a low carb approach of 50 grams of carbohydrates daily. This will lower blood glucose levels on average over time and give you a benchmark to use as a measuring tool.
  3. Slowly add carbs (but watch for when your blood glucose starts to rise!): Once you’ve been following 50 grams of carbohydrate per day for at least three weeks, or until your high blood glucose levels are reduced closer to a healthy fasting range of between 5-7 mmol/L, you can then start adding carbohydrates to determine how much you can tolerate before your blood glucose starts to rise again. For example, if you eat 50 grams of carbohydrates per day for a few weeks and your average blood glucose drops from 8 mmol/L to 6 mmol/L fasted, you can slowly add more carbohydrates to your diet. You might increase to 70 grams per day, then 80 grams, then 100g per day, to determine how much carbohydrate you can safely eat before your blood glucose rises to more than 7 mmol/L again.
  4. Work out your carb tolerance level: Once your blood glucose levels have risen above 7 mmol/L, you have reached your carbohydrate threshold or tolerance levels. You now know how many carbohydrates you can have before your blood glucose reaches unacceptable levels, and so how many grams of carbohydrates you need to stick to per day.

This information is powerful and will allow you to manage your type 2 diabetes as long as you don’t exceed your carbohydrate tolerance!

In summary

  1. Everyone has a different carbohydrate threshold or tolerance level. We can all eat different amounts of carbohydrates before our blood glucose starts to rise and our pants get tight or we experience gastrointestinal symptoms such as bloating or tiredness and fogginess.
  2. To work out your carbohydrate tolerance or threshold level, we recommend you start tracking how many grams of carbohydrate you’re eating each day and your current average fasting blood glucose level.
  3. You might consider a low carb intake of 50 grams of carbohydrates daily until your blood glucose levels drop to a lower and healthier range.
  4. Then slowly start adding more carbohydrates back to your diet. Once you see your blood glucose levels rise above the non-diabetic range and/or your weight go up, this is your threshold or tolerance level. You now know how much carbohydrate you can tolerate.

Improving our blood glucose levels and weight to defeat diabetes is determined by understanding how much carbohydrate and sugar our bodies can tolerate and knowing our carbohydrate threshold.

For more helpful information on preventing, managing and reversing type 2 diabetes, why not start a free trial of the Defeat Diabetes Program?

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