There are plenty of ways to do the keto diet depending on your needs or preferences, and one of them is the Cyclical Ketogenic Diet (CKD) — or cyclical keto, for short.
It’s an approach where you “cycle” between very low-carb, high-fat days and high-carb, low-fat days. Some studies support the idea that upping your carbs on certain days of the week can lead to benefits like increasing muscle mass and athletic performance.
Here’s everything you need to know about the cyclical ketogenic diet — how it works, what makes it different from the standard keto approach, how it may help, doing it right, and possible downsides.
Also called the keto cycle diet, the cyclical ketogenic diet or CKD is a variation of the standard keto diet (low-carb and high-fat) where you go in and out of ketosis on a weekly basis.
Here’s how CKD is done: You eat only up to 50 grams of carbs for 5-6 days in a week (let’s say, from Monday to Friday) but for the remaining 1-2 days (Saturday, Sunday, or both) you’re going to have a higher carb intake. These days in which you eat more carbs are called refeeding days or carb-loading days.
One can think of cyclical keto as a ketogenic diet with carbs.
While most individuals greatly benefit from a standard keto diet — in other words, stick to 50 grams or less daily with no carb refeed days — athletes who do intense training or elite athletes may benefit from added carbs in their diet, as well as highly active people looking to build muscle.
By doing cyclical keto, a person can take advantage of the benefits that ketosis has to offer and the benefits of incorporating carbohydrates strategically.
If you want to give the cyclical keto diet a try, you need to choose which 5-6 days of the week, usually weekdays, you’re going to stick to traditional or standard keto.
On those days, you limit your carbs to 50 grams only and obtain these carbohydrates from keto-friendly foods (mostly plant sources, since plants have carbs) such as spinach, broccoli, cauliflower, brussels sprouts, nuts, and seeds. We call this phase the ketogenic diet phase since your goal on these 5-6 days is to maintain ketosis (*)
For the remaining days of the week, usually weekends, you bring your carbs up to 70-80% of your total calories. For instance, if your daily calorie requirement is 2,000 calories, 70-80% of that goes to carbs, which would be equivalent to 350-400 grams of carbs. We call this phase the carb-loading or refeeding phase since you’re intentionally getting out of ketosis.
As for the foods to eat during your high-carb days, be sure to focus on complex carbohydrates like sweet potatoes, chickpeas, beets, butternut squash, and grains (*).
The reason why complex carbs are best for refeed days is that they take longer to digest and have a more gradual effect on your blood sugar levels (*). In essence, they avoid spikes in your glucose and insulin, which have health consequences.
Important: Note that keto cycling is different from carb cycling in that carb cycling doesn’t necessarily imply that the person doing it is on a ketogenic diet — although it still involves alternating between higher carb and lower carb days.
To recap what was mentioned earlier in this article, cyclical keto allows for more carbohydrates in your diet for up to 2 days a week, whereas standard keto maintains a fat-burning state of ketosis throughout the week.
Below is a brief comparison of the macronutrient percentages for cyclical keto and standard keto:
|Cyclical Keto Diet||Standard Keto Diet|
|Carbohydrates||70-80% of your calories||5% or fewer calories|
|Protein||20-30% of your calories||20-30% of your calories|
|Fats||5% or fewer calories||70-80% of your calories|
Notice that only the values for carbs and fats change with both keto diet approaches. It’s a bad idea to consume high amounts of carbs and fats at the same time. One reason is that it creates an excess of energy and can prevent you from reaching your fitness goals.
When it comes to your dietary protein, it stays the same regardless of whether you’re keto cycling or not.
Cyclical keto isn’t for everyone (especially if you’ve been prescribed a traditional ketogenic diet due to a medical condition such as diabetes, obesity, or epilepsy) but it can be an option for those who would like to see improvements in physical performance, muscle gains, and more.
Here are the possible benefits of CKD:
1. May improve your athletic performance
Working out on keto is totally doable and may even increase ketosis and maintain your fitness levels. This means you can do exercises like cardio (running and cycling) and resistance training (lifting weights).
However, your body can experience dips in energy if you’re often doing longer workouts or workouts that require short bursts of energy like HIIT, sprinting, and agility training. The muscles involved in these explosive workouts tire or fatigue easily, so adding more carbs may allow you to push harder (*).
2. Potential muscle gains
Insulin is a hormone produced by the pancreas and it rises after a person consumes carbohydrates (*).
While insulin is commonly used medically to manage blood sugar levels, bodybuilders take advantage of it to stimulate muscle growth. This is because insulin increases amino acid availability for muscle tissue (*).
So, once or twice a week when you’re doing a refeed, your insulin levels are expected to increase.
However, if you’re trying to avoid too many carbs but love the gym, keep in mind that it’s still possible to build muscle without carbohydrates — like what individuals in the carnivore diet community do — as long as you’re optimizing your protein intake and doing resistance training.
3. May help regulate your weight in the long run
Weight loss stalls can happen on any diet, including the ketogenic diet. If you’re finding yourself not losing any more weight despite limiting your carbs to 50 grams or less daily, you might want to take a look at other factors in your life — such as your activity level, alcohol intake, sleep, and snacking habits (*). These things also affect your weight, and not just your nutrition.
Apart from that, cyclical keto might be worth exploring.
The idea is that strategically increasing carbs may cause leptin to temporarily rise, and leptin is a hormone produced by fat cells to prevent hunger and regulate appetite (*).
A word of advice: Before trying CKD for the main purpose of breaking through a plateau, implement other key strategies first, such as getting quality sleep and managing your stress levels.
4. Sticking to the keto diet becomes easier
If you come from a diet that’s high in carbohydrates, it may take some time before you can fully adapt to keto eating and be able to say that it’s the best approach for you.
The same is also true with any dietary approach that eliminates food groups.
Keto cycling may be beneficial not just for muscle and strength gains and regulating weight, but also for maintaining a very low-carb eating pattern in the long run. You can think of carb refeeding days as “mini-breaks” where you can indulge in sweet potatoes and other complex carbohydrates.
As you return to ketosis, you’ll feel stronger and ready to crush your keto goals again.
5. Added fiber increases gut microbiota
Fiber is a type of carbohydrate and is abundant in whole grains, vegetables, nuts, and beans.
Study shows that dietary fiber influences the diversity and richness of the gut microbiome (which refers to all the microbes in your intestines) (*). Research shows that a diverse microbiome is linked to good health (*).
A cyclical ketogenic diet includes all the foods allowed on a standard keto diet, plus foods that are high in complex carbs and fiber for refeeding days. See the food list below.
- Meat and poultry: beef, pork, lamb, veal chicken, turkey, duck, goose
- Eggs and dairy: chicken eggs, quail eggs, soft and hard cheeses, butter
- Fish and seafood: salmon, mackerel, sardines, tuna, oysters, scallops
- Vegetables and fruits: green leafy veggies, cruciferous veggies, berries during the keto diet phase. Sweet potatoes, beets, chickpeas, butternut squash, grains, beans, carrots, yams during the refeeding phase
- Nuts and seeds: pecans, almonds, macadamia nuts, walnuts, chia seeds, flaxseeds
- Fats for cooking: butter, coconut oil, olive oil, avocado oil, tallow, lard, suet
- Beverages: water, tea, sugar-free berry smoothies, full-fat milk, almond milk
Doing keto cycling involves alternating between ketogenic and refeeding phases. Here’s how you can get started:
Step 1: Get fat-adapted first before starting a cyclic ketogenic diet.
We recommend doing a standard ketogenic diet for a full month before attempting cyclical keto. Sustaining ketosis for a month will allow your body to reach a fat-adapted state, in which it’s already used to burning fat for fuel instead of glucose.
Once you’ve become fat-adapted, you can try cyclical keto. During this period, your body is able to go in and out of ketosis easily — meaning that it’s metabolically flexible.
Step 2: Do a standard keto diet for 5-6 days, followed by 1-2 days of eating more carbs.
Choose your five or six days of the week to eat low-carb (50 grams or less) and stick to that plan. It helps to note your carbohydrate intake and test for ketosis using urine strips to ensure that you’re on the right track.
Next, choose your remaining one to two days to eat more carbs (70-80% of your total calories). You can save your carbs for one meal or consume them during lunch, dinner, and before or after an explosive workout. You decide.
Step 3: After the refeeding phase, get back into ketosis.
Once your refeeding phase is over, return to ketosis immediately.
On top of drastically reducing your carb intake, you may implement strategies like intermittent fasting (IF) and doing high-intensity interval training (HIIT) or steady-state cardio on an empty stomach.
Studies on the cyclical keto diet itself are limited, so we can only make assumptions based on available research on carbohydrate cycling.
It’s important to remember that not everyone who tries CKD experiences the best outcomes. Some downsides may include water retention, tiredness, brain fog, and unhealthy food cravings — as a result of increased carbs.
Learn more answers to common questions on the cyclical ketogenic diet:
Is cyclical keto and carb cycling the same?
No. While both approaches involve cutting and increasing carbs on certain days, carb cycling doesn’t mean that you’re following a ketogenic diet.
Is cyclical keto safe?
Since research on cyclical keto is limited, there’s no complete certainty that it’s safe for everyone. If you’re at risk of diabetes or your body is so sensitive to carbohydrates, then it’s probably best to avoid CKD. Also, speak with your health provider before trying it, especially if you have a medical condition that benefits from a reduced carb intake.
How can I return to ketosis quickly after a cycle?
Strategies that help you achieve ketosis include drastically reducing carbs, intermittent fasting, and exercise. Some people may also take exogenous ketones to increase their BHB ketone levels.
The cyclical keto diet lets you have the best of both worlds. It allows you to experience the health benefits of ketosis and also take advantage of carbs for up to two days to boost your workout performance, muscle growth, and more.
Keep in mind that this approach isn’t for newbies on keto. Before trying it, get fat-adapted. Do at least a full month of standard keto.
And if you’ve been on keto for quite some time now, make sure to implement the things that make a big difference in your fitness progress like quality sleep, stress management, and other daily habits — and even recalculating your protein and fat macros — before giving CKD a shot.