Carb cycling: Is this advanced fat loss strategy right for YOU? (Take the quiz.)
What is carb cycling? | Potential benefits | Quiz: Will carb cycling work for you? | Carb cycling plans++++2. Are you looking for a major body transformation or smaller incremental gains? Consider: Is this the first step of your nutrition journey, or one of the last?3. Have you already tried less advanced strategies (example: eating more veggies) to accomplish your goal? Consider: Is there anything less complex you could try first?4. Are you already consistent and confident with your “big rock” habits? Consider: Will you be able to keep up with your fundamental nutrition practices while you carb cycle?5. How comfortable are you with rigid eating rules? Consider: How do you feel about needing to eat exactly 5 meals or exactly 6 portions of lean protein each day, for example?6. Do you feel comfortable treating carb cycling as an experiment? Consider: Are you okay trying carb cycling even if, ultimately, your experiment determines that this style of eating isn’t for you?7. Are you okay with making tradeoffs to follow a specific eating style? Consider: How would carb cycling impact the way you eat at social gatherings or family meals? Are there foods you might have to skip out on that you normally enjoy?8. Will following a super-specific eating plan stress you out? Consider: Does the idea of not being able to “wing it” with your nutrition—in a restaurant or when you’re running low on groceries, for example—sound stressful?
2. Compared to how I was eating before, I feel better when carb cycling.3. When I carb cycle, I have reliable, sustained energy without crashing.4. Carb cycling feels doable, and fits into my everyday life.5. When I carb cycle, I feel good mentally and emotionally.6. I feel confident and capable cooking and preparing meals while carb cycling.7. When I carb cycle, I feel I am consistently keeping up with the other nutrition, fitness, and health practices that make me feel my best.8. When I carb cycle, I rarely struggle with food cravings or urges to overeat.9. When I carb cycle, I digest my food well.10. I’m performing and recovering well while carb cycling.11. On social occasions, such as going out with friends to a restaurant, I can almost always find something I enjoy and feel comfortable eating.12. I feel calm and relaxed about my food choices. It’s no big deal, just part of life.13. Even if other people pressure me to do something differently, or my style of eating doesn’t match others around me, I’m able to follow my own cues or goals.14. Carb cycling is helping me eat in a way that matches my specific goals for health, fitness, performance, etc.15. I feel I can still truly enjoy food, how it tastes, and the experience of eating.
There’s a reason carb cycling is so popular.According to people who are most enthusiastic about this method (often very fit-looking folks), it’s the perfect diet. They say carb cycling can help you:
- Get the accelerated fat loss that comes from a low-calorie, low-carbohydrate diet… while still eating carbs and… without sacrificing exercise performance.
- Avoid frustrating fat loss plateaus by better regulating hormones like leptin and insulin.
- Gain muscle without gaining much fat.
- What carb cycling is
- How carb cycling works (and how well it works)
- Whether or not carb cycling is the right strategy for YOU (we’ve got an interactive quiz with your name on it)
- How to carb cycle (if you decide to go for it)
- How to determine if your carb cycling plan is actually working—so you can get the results you really want
Want the most important carb cycling information at your fingertips?Download our carb cycling PDF guide, which includes:
- A carb cycling cheat sheet for quick and easy reference
- A pre-carb cycling assessment
- A step-by-step plan for figuring out if it works for you
Okay, so what is carb cycling?Carb cycling is when you fluctuate between eating low-carb foods and high-carb foods. The most common carb cycling approach is to eat fewer carbohydrates on some days and more carbohydrates on other days. People who carb cycle usually end up calorie cycling, too. This means they eat fewer calories on their “low-carb days” and more calories on their “high-carb days.” For example, a typical carb cycling schedule might look like this:
- Non-workout days: low carb, low calorie
- Workout days: high carb, high calorie
Why focus only on carbs and not protein or fat?First and foremost, varying your carbohydrate intake may have a positive impact on many important hormones (we’ll dig more into that in a minute). Fluctuating your fat and protein intake, on the other hand, won’t affect hormones for the better. There’s also this: Not-so-great stuff can happen when you don’t get enough protein or fat. For example, if your fat intake stays too low, your menstrual cycle might halt. And if your protein intake stays too low, you can lose muscle and experience mood swings. You’re probably not interested in any of that, let’s just keep this conversation about carbs.
What does carb cycling do, exactly?In theory, it can do quite a few things. So we’ll give you a rundown of the top five potential benefits of carb cycling. But before we do, it’s important to know: There’s hardly any human research on carb cycling. Mostly, we have anecdotal reports about how carb cycling works, along with a few hypotheses based on biochemistry. Those are valuable, but on a 1 to 10 scale of scientific confidence, carb cycling ranks closer to a 1 than a 10. So keep that in mind when you hear or read claims about carb cycling. Okay, enough with the disclaimers. Here’s what carb cycling might do.
#1: Carb cycling may help keep your metabolism humming during fat loss.When you eat less—say, to lose fat—your body responds in a variety of ways. For example:
- Your basal metabolic rate (BMR) drops
- You expend less energy when you exercise
- Your daily activity outside of workouts tends to decrease naturally (you move around less without even realizing it).
#2: Carb cycling may help regulate hormones affected by fat loss.Intense dieting can mess with your hormones. Specifically:
- Thyroid hormones
- Reproductive hormones (testosterone and estrogen)
#3: Carb cycling may make it easier to stick to a low-carbohydrate diet.Low-carb diets can be effective for fat loss, especially for people with type 2 diabetes and metabolic syndrome.4 (It should be noted, though, that they’re not necessarily more effective than low-fat, high-carbohydrate diets.5 6) What counts as low carb? You might call any diet that provides fewer than 30 percent of your daily calories from carbs a “low-carb diet.” (Experts often debate the exact percentage here, with some saying it’s 20 percent and others saying it’s even less.) The ketogenic diet, a popular form of low-carb eating, is more specific. It’s very low in carbs, and very high in fat (usually <10 percent carbohydrate and >60 percent fat). (To understand more about the differences between keto and low carb, see: The ketogenic diet: everything you need to know.) Though low-carb and ketogenic diets can be effective for fat loss, most people can’t stick with them over a longer period of time. (This also goes for any other kind of restrictive eating style.) So it’s been suggested that alternating between lower-carb and higher-carb days may better help people maintain a lower-carb eating style—and their results—long-term. In the case of someone doing keto, this is referred to as a cyclical ketogenic diet. You could think of it this way: You eat a ketogenic most of the time but have little mini-breaks—that last a day or two—where you can enjoy higher-carb meals.
#4: Carb cycling may support athletic performance on a low-carb diet.The ketogenic diet is also sometimes used by athletes who want to be fat adapted. Being fat-adapted allows you to burn greater amounts of fat at higher exercise intensities, according to several studies.7 8 9 Burning more fat always sounds like a good thing, of course. But how might it help with exercise performance? That deserves a little more explanation. Here’s the background: To fuel long bouts of endurance exercise, your body normally relies heavily on carbohydrates stored in the form of glycogen. Unfortunately, your body can only store so much glycogen at a time. So if you exercise long enough, you’ll run low on carbs and have to slow down. That’s why endurance athletes usually consume 60 to 90 grams of carbohydrates per hour during competitions. It gives them more fuel so they can keep going hard. This is where being fat-adapted may come in handy. As many of us know all too well, it’s easy for your body to store lots of fat in the form of fat tissue. Even very lean people have 15 times more energy available from stored fat than from stored carbohydrate.10 So if you become fat-adapted, your body relies more heavily on fat—instead of carbs—to fuel long endurance exercise. That would mean you wouldn’t have to deal with the inconvenience (and potential GI distress) of consuming an energy gel every 90 minutes during a longer exercise session.11 Plus, it might make you less likely to “bonk.” Some have even suggested being fat-adapted could help improve exercise performance and recovery, too, though this is debated by researchers.12 Now, keep in mind: All of the above is only referring to how a ketogenic (low-carb, high-fat) diet might benefit endurance performance. So how does carb cycling fit in? The idea is this: You get fat-adapted by eating a ketogenic diet for several days. But then you cycle in a couple of high-carb days. These high-carb days allow you to max-out your glycogen stores. The hope is that you can do this without disrupting the hypothetical performance benefits of the ketogenic diet. Combined, this could give you the best of both worlds: Lots of energy to burn, from both carbs and fat. It’s important to note, though, that the evidence doesn’t currently support the performance benefits of a ketogenic diet on a wide scale. So based on what we know now: For most people, adopting a cyclical ketogenic diet specifically because you want to perform better is most likely more trouble than it’s worth.
#5: Carb cycling may promote muscle gain without fat gain.Fat gain almost always accompanies muscle growth. But some carb cycling enthusiasts say the key to gaining muscle without gaining much fat is the hormone insulin. Whenever you eat carbohydrates, your blood sugar rises, and insulin is released. Insulin helps regular your blood sugar levels. It also plays a key role in muscle growth and glycogen storage. The hypothesis goes:
- If you eat high carb on days you resistance train, you can take advantage of insulin’s muscle-building and recovery properties
- If you eat low carb on rest or conditioning workout days, you can simultaneously lose fat and improve insulin sensitivity, making the high-carb days even more effective
Remember: We’re not totally sure carb cycling works.What are we more confident about? The big rocks. Imagine your time as a jar that can be filled with a finite number of rocks, pebbles, and grains of sand. The big rocks are the eating and lifestyle practices most necessary to see results. (You can read more about these in our article on the 5 universal principles of good nutrition.) The pebbles are things that’ll help but aren’t totally necessary. The sand is purely “bonus” stuff. It may help, but it’s not crucial, and it won’t have a big impact. Carb cycling is a sand habit. So… does carb cycling work? If you mean, “Can carb cycling help me lose fat and improve body composition?”, the answer is yes. As long as, overall, you’re expending more calories than you’re consuming. It might even work great for you, if it’s a good fit for your eating preferences and lifestyle. But if you mean, “Is it superior to other methods?”, that’s hard to say. Because lack of evidence. Our take: If it provides any incremental benefit, it’s minute. For most people, it’s a high effort, low impact deal. (The key term here is most people. For example, if you’re an athlete with more than one competition in a day, nutrient timing is a whole lot more important.)
Who should try carb cycling?Though carb cycling isn’t right for everyone, it can work for specific types of people.
You’re most likely to benefit from carb cycling if…You have your big rock habits down. You’re already eating lots of minimally-processed whole foods and little highly-processed fare. You’re exercising. You’re getting plenty of quality sleep. And you’re eating mindfully. And because these big rocks are already in place, carb cycling becomes something to experiment with—instead of being the primary method of achieving results. Since we aren’t 100 percent sure carb cycling works in all scenarios (in fact, not even close to 100 percent sure), this is an important box to check before getting started. You’re already very lean but want to get leaner. When you’ve already gotten super lean, your body will start to fight every last bit of fat loss. Cycling calorie and carb intake might help stave off the metabolic adaptation that often occurs with a chronic, ongoing calorie deficit. Plus, cycling intake can make a calorie deficit feel like less of a grind. That’s because it lets you block off “eat less” days into small, manageable units instead of several weeks of miserable, hungry slogging. You want to manage training and nutritional stress (and are already implementing other key strategies). If you’re concerned about how the stress of hard training and a chronic calorie deficit is affecting your hormones, you might consider carb cycling. Provided you’re also doing other things to manage their total stress load—like sleeping enough, meditating, and practicing self-compassion—periodically “topping off” energy and carbohydrate stores can tell your body that everything’s okay, and starvation isn’t imminent. This is particularly useful for:
- Women (whose central hormonal regulation systems may be very sensitive to nutritional deficits, which is one of the reasons intermittent fasting isn’t always so great for women)
- Leaner people (who usually have less circulating leptin)
- Anyone who doesn’t tolerate stress well or who already has a high stress load
What about “carb cycling kickstart” challenges?Usually, we don’t recommend carb cycling as a first step to better eating habits. That’s because popular carb-cycling challenges are often hyperspecific, requiring you to eat exactly five meals a day and adhere to precise macronutrient ratios. Few people can stick to something like that for very long. So is it likely that a 14-day carb cycling challenge will change your life forever? Not really. But it’s possible. We know that action leads to motivation. So if doing this kind of program helps you get motivated to take more steps to improve your nutrition habits, that’s awesome. People who see early success with their nutrition efforts are more likely to continue making progress thanks to the motivation boost. But if you choose this route, we’d like to offer one helpful nugget of advice: Have some sort of transition plan in place to help you get to a more sustainable eating pattern afterward. Where to start? You can increase your chances of long-term success by picking out some “big rock” habits to focus on afterward.
Should YOU try carb cycling?Let’s find out. Use this handy quiz to determine if carb cycling makes sense for you. 1. Do you know what you hope to get out of carb cycling? Consider: Do you want to lose fat? Gain muscle? Better regulate stress or your hormones?
No idea 100 percent clear012345
Transformation Smaller gains012345
No previous steps Tried everything else012345
Not consistent at all Super confident012345
Flexibility is very important I’m okay with rules for now012345
No, I need to be sure it’ll work I’m all for experimenting012345
Not okay Totally comfortable012345
Extremely stressful I’m good with a specific plan012345
Total score: –32-40: It’s a go! Sounds like you’re in a great place to give carb cycling a try. You’re clear on your goals, your big rocks are in place, and you’re willing to make the tradeoffs. 24-31: Proceed with caution. Carb cycling may or may not make sense for you. If you’d still like to give it a try, use outcome-based decision making (using the data you collect about your experience to decide what to do next) as you experiment with one of the protocols below. Basically, that means checking in with yourself and being honest about how it’s going for you. 0-23: Consider keeping carb cycling in your back pocket. It looks like you’d benefit from less advanced nutrition and health practices. (That doesn’t mean you should never try carb cycling in the future.) These fundamental practices include eating lean protein with meals, choosing minimally-processed whole foods most of the time, consuming several servings of colorful veggies each day, getting restful sleep, and reducing stress, among many others. If you’re still interested in carb cycling after getting those big rock habits in place, retake this quiz, and see how you do.
How to carb cycle for fat loss or muscle gainHere at Precision Nutrition, we use a variety of carb-cycling methods depending on a person’s goals and nutrition experience. Below, we’ve outlined the two carb cycling methods we use most often. Before we dive in, though, let’s go over two key points. 1. Customize your carb cycling schedule. To adjust these carb cycling plans for your goals and body, you’ll want to use the Precision Nutrition Calculator. This will help you determine your baseline nutrition needs (in calories, macros, and/or hand portions). Ultimately, no matter which cycling strategy you use, total calorie and macronutrient intake for the week should remain the same as if you’re not cycling. For example, let’s say you’re looking to gain muscle, and the calculator determines you need a daily intake of:
- 7 palms or 210 g protein
- 6-8 fists of veggies
- 8 handfuls or 250 g carbs; and
- 7 thumbs or 100 g fats.
- What’s the goal you’re trying to achieve?
- How will you know if you’re making progress? Will you measure your weight, body composition, girth measurements, exercise performance?
- How often will you check in to determine whether you’re making progress or not?
Carb cycling plan #1: Use high/low days.This carb and calorie cycling approach is very simple and is based on your level of daily activity. Remember, first calculate your average daily needs using the Precision Nutrition Calculator. Then you’ll fluctuate your daily carb intake as follows.
- On days with minimal physical activity: Eat mostly protein, vegetables, and healthy fats with minimal carbs (about 25-50 percent of your estimated daily carb need from the calculator, whether in grams or cupped handfuls).
- On days with physical activity and/or planned exercise: Add starchy carbs to the baseline diet (about 150-175 percent of your estimated daily carb needs, whether in grams or cupped handfuls).
Carb cycling plan #2: Use post-workout/anytime meals.Another approach is to put the bulk of a day’s carbohydrate intake in the meal that follows physical activity (post-workout), while minimizing carbohydrates at other meals (anytime). For a visual of what a Post-workout (PW) or Anytime (AT) meal could look like, see below. An AT meal, as its name implies, can be eaten any time outside of exercise. An AT meal:
- Has serving of lean protein (about 1-2 palms, or as calculated)
- Has a serving of healthy fats (about 2-3 thumbs, or as calculated)
- Fills out the remainder with non-starchy vegetables (ideally colorful ones)
- Has a serving of lean protein (about 1-2 palms, or as calculated)
- Is lower in healthy fats (about 0.5-1 thumb, or as calculated)
- Has a large serving of carbohydrates (generally at least 50 percent or more of the calories for that meal, or about 3-5 cupped handfuls or as calculated)
|Monday: workout day||Tuesday: No workout but still physically active||Wednesday: No workout and not physically active|
|Meal 1: Anytime||Meal 1: Anytime||Meal 1: Post-workout|
|Workout||Ride bike to work and work physically active job|
|Meal 2: Post-workout||Meal 2: Post-workout||Meal 2: Anytime|
|Meal 3: Anytime||Meal 3: Anytime (possibly Post-workout if extra calories needed)||Meal 3: Anytime|
|Meal 4: Anytime||Meal 4: Anytime||Meal 4: Anytime|
A quick note on advanced carb cycling methodsMore advanced forms of carb cycling can be used by people like elite amateur and professional athletes, people whose income is tied to their appearance (like models), and bodybuilding and figure competitors. If you’re a coach and you’re interested in learning more about these advanced protocols, we cover them in-depth in our Precision Nutrition Level 1 Certification. If you’d like to try advanced carb cycling yourself, we’d recommend doing so with the assistance of a qualified nutrition coach.
Carb cycling: How’s it REALLY working for you?After you’ve been carb cycling for at least 2 weeks, use this assessment to decide if the eating strategy is working for you. Think about your recent experiences with carb cycling. Then, choose the number that best matches how strongly you agree with the following statements. On a scale of 1 (never) to 10 (always), most of the time… 1. When I eat this way, I feel pretty good in general.
Total score: –120 and above: Crushing it! This way of eating is working beautifully for you. Keep on doing your thing. 105 to 119: This is promising. Overall, things are going well with your carb cycling experiment. You might consider making some small changes, but it looks like you’re moving in the right direction. 76 to 104: Mixed results. Carb cycling might be working well for you in some areas, but you’re probably struggling in others. Consider if there are any tweaks you could make that would make it feel more sustainable. Less than 75: Carb cycling is not working for you. Based on this assessment, you’re experiencing some issues with the carb cycling protocol you’re currently following. Success depends on a plan you can stick with consistently that has minimal tradeoffs. And don’t feel bad about this. This experiment helped you to understand something important: Carb cycling may not be for you—at least, right now.
Carb cycling may or may not work for you.No matter what happens during your carb cycling experiment, remember this: It’s all okay. You might learn that you just can’t stick to a carb cycling regimen. Or that you feel terrible when carb cycling. Or maybe you feel great. Or perhaps you learn that carb cycling is your favorite way of eating. Or that it’s just not worth all the effort. Or something else. It’s all good. The key is to keep an open mind and go with the best available evidence: your own personal experience (based on the assessment above). Collect your data and then reflect on how things are going. If you stick to the facts, you can’t go wrong.
ReferencesClick here to view the information sources referenced in this article.
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