Carb Tolerance On Keto: Finding Your Sweet Spot

Carbohydrate tolerance, or how your body responds to dietary carbohydrates, is an important aspect of health and wellness. It can help you make better dietary choices and improve your metabolic health. While there is no one-size-fits-all approach to determining your carb tolerance, there are several methods you can use to gauge it, especially when following a keto diet.

One way to test your carb tolerance is through an oral glucose tolerance test (OGTT). This involves drinking a glucose solution and monitoring your blood glucose levels over the next few hours. However, this method may not be practical for everyday use. A more feasible option is to measure your blood sugar before and after consuming a carbohydrate-containing meal. By tracking your blood sugar levels at one and two hours after eating, you can assess your body's response to different types of carbs.

Additionally, you can pay attention to how your body feels. Mental fog, fatigue, and intense cravings may indicate that you are consuming too many or poor-quality carbohydrates. You can also use tools like a continuous glucose monitor (CGM) or your bathroom scale to help determine your carb tolerance. The CGM provides a visual map of how your body handles carbs throughout the day, while the scale allows you to compare your daily carb intake with weight fluctuations.

It's important to remember that your carb tolerance is unique to you and can change over time as your body composition, activity level, and health status evolve. By using a combination of these methods, you can better understand your body's response to carbohydrates and make more informed dietary choices to support your health goals.

What is carb tolerance?

Carbohydrate tolerance, or carb tolerance, is not a scientifically defined term, but it is a valuable concept. It refers to your unique metabolic and digestive response to dietary carbohydrates. In other words, it paints a picture of your metabolic health.

Carb tolerance is often synonymous with glucose tolerance, a medical term that refers to how well your body manages blood sugar (blood glucose) levels. Those with impaired glucose tolerance, such as those with pre-diabetes and type 2 diabetes, are at higher risk for heart disease, certain cancers, and neurodegenerative diseases.

The keto diet is a promising therapy for glucose intolerance. It is a low-carbohydrate method of eating that replaces carbohydrates with fats, putting the body into a state of ketosis. To stay in ketosis, a person can consume up to 50 grams of carbohydrates per day.

Your carb tolerance may also be related to how your digestive system responds to carbohydrates, particularly if you have irritable bowel syndrome (IBS). People with chronic gut issues often have an overgrowth of unfriendly bacteria, and feeding this overgrowth with carbs can make things worse.

There are several ways to test your carb tolerance, including the oral glucose tolerance test (OGTT), which is considered the gold standard for assessing your metabolic response to carbs. You can also perform your own "real-world" glucose testing by measuring your blood sugar before and after consuming a carbohydrate-containing food or meal. Additionally, your primary care physician may order fasting insulin, fasting glucose, or a Hemoglobin A1c (HbA1c) test to assess your blood sugar during your office visit.

Your carb tolerance depends on various factors, such as age, activity level, past diet, health history, and genetics. These factors impact how sensitive your cells are to insulin and, therefore, how many carbohydrates your body can tolerate. As you continue to follow a low-carb or keto diet, your carb tolerance may change over time as your body becomes more efficient at burning fat for energy.

How to measure it

How to Measure Carb Tolerance on Keto

Carb tolerance refers to an individual's metabolic and digestive response to dietary carbohydrates. It is not a medical term, but it is a valuable concept for understanding your metabolic health. Carb tolerance is often synonymous with glucose tolerance, which refers to how well your body manages blood sugar (blood glucose) levels.

Knowing your carb tolerance can help you make better dietary choices and improve your metabolic health. For example, if you know that white rice causes a spike in your blood sugar, you can avoid consuming it. Additionally, understanding your carb tolerance can help you identify foods that may be causing digestive issues.

How to Measure Carb Tolerance:

There are several ways to measure your carb tolerance:

• The Oral Glucose Tolerance Test (OGTT): This is considered the gold standard for assessing your metabolic response to carbs. For this test, you drink a glucose solution and record your blood glucose levels in the hours that follow. Clinicians use OGTT results to quantify your risk for diabetes. However, the OGTT has limited real-world applicability as most people do not consume pure glucose.
• Real-World Glucose Testing: Instead of drinking a glucose solution, you can test your blood sugar response to carbohydrate-containing foods or meals that you would typically consume. Measure your blood sugar before eating, then consume the food you want to test. Measure your blood glucose again at one hour and two hours after the meal. You can interpret the results using the OGTT guidelines, but keep in mind that optimal levels are likely lower than 140 mg/dL at two hours post-meal, as whole foods will not spike your blood sugar as much as pure glucose.
• Blood Tests at Your Doctor's Office: Your primary care physician or endocrinologist may order fasting insulin, fasting glucose, or a Hemoglobin A1c (HbA1c) test to assess your blood sugar during your office visit. A HbA1c of 5.7-6.4 indicates pre-diabetes, while an HbA1c of 6.5+ indicates type 2 diabetes. Elevated fasting insulin or blood sugar levels can also indicate lower carb tolerance.
• Continuous Glucose Monitor (CGM): This is a small monitor that painlessly attaches to your arm and continuously records your blood sugar level. The accompanying app provides a clear visual map of how your body handles carbohydrates throughout the day. This tool can help you identify which foods may be causing spikes in your blood sugar.
• Bathroom Scale: You can also use your bathroom scale as a tool to determine your carb tolerance. One way to do this is by using a step-down method, where you record your daily carb intake and gradually reduce the amount to achieve your desired weight loss or blood sugar goals.
• Mental and Physical Symptoms: Monitoring how you feel mentally and physically can also provide clues about your carb tolerance. If you experience mental fog, fatigue, or heightened cravings, it may be an indication that you are eating too many or poor-quality carbohydrates.

Tips for Improving Carb Tolerance:

If you find that your carb tolerance is not where you want it to be, there are several things you can try:

• Exercise: All types of exercise increase the ability of insulin to regulate blood glucose, giving you a wider range to consume carbs while maintaining metabolic health.
• Sleep: Getting seven to nine hours of restful sleep per night helps insulin do its job. Lack of sleep can negatively impact your glucose regulation.
• Stress Management: Managing stress is crucial for metabolic health. The "stress hormone" cortisol elevates blood sugar and decreases fat burning.
• Eat Fibre-Rich Carbs: Consuming fibre along with starch and sugar can blunt the blood sugar response. Fruits and vegetables are good options for fibre-rich carbs.
• Try Different Carbs: Monitor how different types of carbs, such as rice, sweet potatoes, or apples, influence your blood sugar, digestion, and energy levels.
• Try a Ketogenic Diet: A very low-carb ketogenic diet has been shown to improve glucose regulation in obese and diabetic populations. Minimizing carbs may also help with weight loss, gut health, and mental acuity.
• Intermittent Fasting: Intermittent fasting has similar metabolic effects to the keto diet, improving glucose regulation and giving your gut time to heal, potentially increasing your tolerance to various foods.

How to improve it

How to Improve Your Carb Tolerance on Keto

If you want to improve your carb tolerance, there are several strategies you can try. Remember, carb tolerance is about understanding your body's metabolic and digestive response to carbohydrates, so these tips will help you enhance your metabolism and digestion of carb-rich foods.

Exercise

All forms of exercise increase your body's ability to use insulin to regulate blood glucose. This means you can consume more carbs while staying metabolically healthy.

Get Good Sleep

Getting 7-9 hours of quality sleep per night helps insulin do its job effectively. Lack of sleep can negatively impact your glucose regulation.

Manage Stress

The stress hormone, cortisol, increases blood sugar and reduces fat burning. Find what works for you to manage stress, such as exercise, meditation, yoga, counselling, or spending time with loved ones.

Eat Fibre-Rich Carbohydrates

Consuming fibre along with starch and sugar helps blunt the blood sugar response. Opt for fruits and vegetables to get your fibre.

Experiment with Different Carbohydrates

Monitor how various carbs like rice, sweet potatoes, and apples affect your blood sugar, digestion, and energy levels. This will help you understand which carbs work better for your body.

Try a Low-Carb or Keto Diet

Consider trying a very low-carb ketogenic diet, which has been shown to improve glucose regulation, aid weight loss, improve gut health, and enhance mental clarity. You can always reintroduce carbs later if needed.

Intermittent Fasting

Intermittent fasting has metabolic effects similar to the keto diet, improving glucose regulation and giving your gut time to heal.

How to calculate net carbs

Net carbs refer to the amount of carbohydrates that are absorbed by your body. They are sometimes referred to as digestible or impact carbs. Net carbs include both simple and complex carbs. Simple carbs are found in foods like fruits, vegetables, milk, sugar, honey and syrup, while complex carbs are found in grains and starchy vegetables like potatoes.

To calculate net carbs in whole foods, you subtract the fibre from the total number of carbs. For example, an avocado contains 17.1 grams of total carbs, 13.5 grams of which is fibre. So the net carbs are 3.6 grams (17.1 grams total carbs – 13.5 grams fibre = 3.6 grams net carbs).

To calculate net carbs in processed foods, you need to look at the nutrition label. Generally, you can subtract half of the carbs from sugar alcohols from the total carbs listed. Erythritol is an exception to this rule; if it's the only sugar alcohol listed in the ingredients, you can subtract its total carb value from the total carbs.

Here's a formula for calculating net carbs:

Total Carbs (g) – Fibre (g) – Erythritol (g) – Allulose (g) = Net Carbs

If the processed food contains a sugar alcohol other than erythritol, you can divide its value in half and subtract that number from the total carbs:

Total Carbs – Fibre – (Other Sugar Alcohols ÷ 2) = Net Carbs

It's worth noting that the Food and Drug Administration (FDA) does not recognise the term "net carbs" and instead recommends using the total carbohydrates listed on nutrition labels.

Tips for the keto diet

The keto diet is a low-carb, high-fat diet that can have benefits for weight loss, inflammation, and overall health and well-being. Here are some tips to help you get started and stick with the keto diet:

• Understand the basics of the keto diet: The keto diet is a high-fat, low-carb diet that trains your body to get its energy from ketones produced by the liver, instead of glucose. This means that carbs need to be severely limited, and your body will go through a transition period before it becomes metabolically flexible and can easily switch between using glucose and ketones for energy.
• Calculate your carb limit: The number of carbs you can eat on the keto diet depends on your individual goals and health status. As a general guideline, most people should aim for up to 50 grams of carbs per day to stay in ketosis. However, this may vary depending on factors such as age, activity level, past diet, health history, and genetics.
• Choose the right foods: On the keto diet, you'll be eating high-fat, low-carb foods. This includes fresh meat and fish, cheese, dark green vegetables like broccoli, and healthy fats like avocado and olive oil. Wheat-based products, rice, pasta, cereals, beans, and legumes are high in carbs and should be limited.
• Ease into the diet gradually: Starting the keto diet doesn't have to be an all-or-nothing affair. You can gradually reduce your carb intake by cutting out one type of high-carb food at a time, such as bread or juice. This can make the transition easier and help you stick to the diet in the long run.
• Focus on whole, unprocessed foods: Whenever possible, choose whole, unprocessed foods that are rich in nutrients. This will ensure you're getting enough vitamins and minerals, even while limiting your carb intake.
• Monitor your health: The keto diet can be restrictive, and it's important to make sure it's not having any negative effects on your health. Regularly check in with your doctor or healthcare provider to monitor your heart health and overall well-being. This is especially important if you have any pre-existing health conditions, such as diabetes.
• Be mindful of side effects: The keto diet can cause side effects like the keto flu, which is a period of fatigue and lethargy as your body adjusts to using fat for energy instead of carbs. Stay hydrated, get enough rest, and consider taking supplements to help alleviate any side effects.
• Experiment with different carbs: Not all carbs affect everyone the same way. You may find that you tolerate some carb-rich foods better than others. Try experimenting with different types of carbs and pay attention to how they make you feel. You can also try a "real-world" tolerance test by measuring your blood sugar before and after eating a carb-containing food to see how your body responds.
• Try intermittent fasting: Intermittent fasting can be a useful tool when combined with the keto diet. It can help improve glucose regulation and give your gut time to heal, potentially increasing your tolerance to various foods.
• Be consistent but flexible: Consistency is key when it comes to the keto diet. Stick to your carb limit most of the time, but don't be too hard on yourself if you have an occasional indulgence. Remember that falling off the wagon is not a big deal, and you can always get back on track.

Frequently asked questions