If you’re on a keto diet, you know that staying and getting into ketosis (the whole goal of going keto), is achieved by eating a very high fat, moderate protein, and low-carb diet. You probably also know that the perfect amount of daily carbs is different for each person; some people can easily get into ketosis and stay there on 50 grams of toal carbs per day while others need to stay at around 20 grams of total carbs per day. So how do you determine the right amount of carbs for you? Read on to learn everything you need to know.
Carb Limits for Keto Beginners
The fact is, the amount of carbs you can tolerate and stay in ketosis depends on your particular body, how long you’ve been living keto, your exercise regime, and more. So, when you’re first starting a keto diet, it’s recommended to stick with 20 grams of net carbs per day or 20 grams of total carbs for therapeutic purposes. While 20 grams of total carbs is the amount that can get pretty much everyone into ketosis provided you eat within your daily macros, 20 grams of net carbs is the starting point for most people trying to achieve weight loss or general health benefits. To learn more about the difference between total carbs and net carbs, see below or read more here.
To ensure your body completely acclimates to the keto lifestyle, it’s recommended that you stick to 20 grams of net carbs per day for a full three months before you set out to explore your own personal carb edge.
Quick Net Carbs Primer
Net carbs are the total carbs minus the fiber (minus sugar alcohols if applicable). For example, a medium red bell pepper has 7 grams of total carbs and 2.5 grams of fiber. Therefore, the net carbs in a red bell pepper are 4.5. This is the number you would track to monitor your carb intake each day.
How to Determine if You’re in Ketosis
The best way to see if you’re in ketosis is to regularly test your blood using a blood-ketone testing meter. (For the most reliable results, be sure you follow the guidelines on exactly how to test and when to test.)
When you first embark on a ketogenic diet and begin testing your ketones, you’ll see your ketone levels start to rise from “Lo” to 0.1 mmol/L (the first measurable result) and higher. You’re in nutritional ketosis at 0.5 mmol/L.
- Brain fog
Meanwhile, your body may give other indications, too, including:
- A slight fruity or acetone smell on your breath, also known as “keto breath”
- Increased energy (this typically happens once you’re in full ketosis)
- Decreased sugar cravings
- The ability to go longer between meals
How to Test Your Carb Limit
Once you’ve been steadily in ketosis for three months, you’re in a good position to test your carb edge, i.e. figure out whether you can tolerate more net carbs each day yet still stay in ketosis.
So that you don’t kick yourself out of ketosis or, if you do, you can recover quickly, it’s important to test your carb limit methodically. The best way to do this is to gradually increase your net carbs, test your ketones and glucose with your Keto-Mojo blood-glucose testing meter along the way, and stop when your test results come too close to pushing you outside of your optimal ketosis range.
Start by increasing your daily net carbs by 5 grams, so that your daily net carbs become 25 rather than 20. Stay at this increase for at least 3 days, testing to monitor your tolerance and ensure you remain in ketosis. If you get kicked out of ketosis, immediately dial back to 20 net carbs per day and know that you are already at your edge.
If you successfully stay in your desired range of ketosis on 25 net carbs per day for one week, bump your net carbs up to 30, try that for a week, and see how you fare.
Remember, we all have different carb tolerance. Some people easily get kicked out of ketosis when going above 20 grams of net carbs per day. Others can eat many more carbs yet remain in ketosis. Along with lifestyle, such as exercise, bio-individuality determines your carb edge. You can learn more about it from this quick, nifty video: Self Experimentation & Bio-Individuality on the Keto Diet
Step-By-Step Guide to Testing Your Carb Limit
Here are some easy to follow steps to help you determine your daily carb limit:
Day 1 through 3:
Increase your daily carbs by five net grams (i.e. from 20 to 25 grams), then test your ketones and glucose (see below for best times to test) to see how your body is responding. If your ketones drop significantly (and especially if they are below .5 mmol) and glucose rises more than 30 mg/dL after several hours, go back down to 20 grams of net carbs and know that 20 grams of net carbs are your daily limit.
If you remain in ketosis on 25 net grams of carbs per day (0.5 mmol or above, but ideally higher), stay at this level and continue testing for three full days. Ketone changes don’t show up as quickly as glucose does in test results, so this allows you time to ensure you’re truly still in ketosis before adding more carbs to find your edge.
Day 4 through 6:
If you’re still in ketosis at 25 net grams of carbs per day, Increase your daily net carbs by 5 grams again, so you’re daily net carb consumption is 30 grams of net carbs. Again, test your ketones and glucose to see how your body is responding as described above. If you continue to stay in ketosis throughout the day, continue consuming 30 net carbs per day for three days.
Three day increments:
If you’re still in ketosis at 30 net carbs per day, you can continue to increase your net carbs by 5 grams every three days until you reach your personal carb limit or “carb edge” (the amount of carbs you’re able to consume without getting kicked out of ketosis). Keep in mind that your ketosis levels can be affected by other factors as well (see below), so be sure to test your ketones and glucose frequently until you know for sure what your upper limit is.
The Best Time to Test
The best way to get the clearest results from testing your ketones and blood glucose is to test before you eat and 30 and 120 minutes after you’ve eaten and to be consistent about your testing times. (You can read more about the best times to test ketones and glucose here.) So, pick a time to test that works best for you, and try to be consistent with that same time each day. Then you can compare your results to the days prior at the same time. At a minimum, when determining your daily carb limit, you may want to test two hours after you wake up (while fasted) to get your baseline test result, and again two hours after meals.
Factors That Can Influence Your Daily Carb Limit
Your carb limit can change based on your bio-individuality and other lifestyle factors. The following are some influences and what you can do to help ensure they’re working in your favor:
Emotional Stress Levels
Emotional stress can impact your insulin response to the stress hormones, so if testing your ketones and glucose on a stressful day, you may notice a rise in glucose which can suppress your ketones. Finding ways to manage stress, such as going for walks, yoga, deep breathing, and making changes in your life to decrease your stress levels, can help your glucose and your overall well-being.
The effects of coffee on glucose and insulin are bio-individual. For some people, coffee consumption can raise glucose, while other people see no change and others find it improves glucose metabolism and insulin sensitivity. To find out how coffee affects you, test your glucose before drinking coffee and 30 minutes after coffee to see how your glucose levels react.
Exercise can have an impact on insulin in two ways. First, stress from overtraining (long intense workouts without taking recovery days) can raise cortisol, which impacts insulin and can raise glucose. So be sure to take rest days and allow your body to recover. Second, exercise/muscle contraction activates glucose transport. As this acute effect of exercise on glucose transport wears off, it’s replaced by an increase in insulin sensitivity. So right after exercise, you may find a slight rise in glucose. If this is the case for you, test again 1 hour later, to see if your glucose drops back down. That said, light exercise can help burn more fat and get you into ketosis faster. Once again, test your glucose and ketones before and after exercise to see how your body is responding.
Researchers found that a single night of partial sleep loss impairs fasting insulin sensitivity. So the best measurement results are after a full night of sleep. To determine if interrupted sleep affects your glucose, test each morning around the same time, while fasted, and record whether you had a full night of sleep or an interrupted night’s sleep.
Type of Carbs
Different forms of carbohydrates can affect insulin in different ways. Eating simple sugars from candy and juice will rapidly increase insulin and glucose, which can affect your ability to remain in ketosis. Complex carbs are digested more slowly, and therefore will have less of an impact on your glucose and insulin. Be sure to eat plant-based, low starch, above ground vegetable sources of carbs (such as broccoli, cauliflower, asparagus, and zucchini). If you’re eating fruit, stick with low glycemic fruit like berries.
With so many factors and tests in play to determine your carb edge, it’s a good idea to track your data so you can analyze your results. Once you determine a pattern, you can make the appropriate lifestyle changes based on what you know about your body and your various activities. For example, if your sleep is disrupted one day and you know your glucose rises with coffee yet you meet a friend for coffee that day, consider giving yourself a buffer by decreasing your carbs for that day. With some investigation and exploration, you’ll get a very clear sense of how to ride your carb edge without exceeding it.