What Is a Carb Cycling Diet? How It Can Boost Weight Loss Efforts

Perhaps you’ve heard that your metabolism is a lot like a fire: If you fuel “the fire” with the right ingredients it keeps burning hotter. On the other hand, not adding enough fuel for too long will cause the fire to weaken and fizzle out.

When looking for how to lose weight fast, carb cycling — eating more carbs only on certain days of the week— is believed to be one of the best plans because it stimulates certain digestive and metabolic functions that positively impact weight control. Eating enough carbohydrates at the right time resets your “metabolic thermostat” so to speak, signaling your body to create enough beneficial hormones (like leptin and thyroid hormones) that keep your appetite in check and metabolism high. However, as we all know, too many carbs can have the opposite effect and cause weight gain.

What’s key about a carb cycling diet that makes it different from other plans? Carb cycling increases carbohydrate (and sometimes calorie) intake only at the right time and in the right amounts. While other long-term diet plans might seem overly restrictive, daunting and overwhelming, many find that a carb cycling diet is easy to follow and even fits into a hectic schedule.

What Is Carb Cycling?

Carb cycling is a type of diet plan that involves eating more carbohydrates on certain days of the week, but doing the opposite on the other days: cutting carbs very low in order to achieve easier weight loss.

In other words, following a carb cycling meal plan means that you eat adequate amounts of carbs (ideally those that are unprocessed and nutrient-dense) about every other day, or every few days, depending on your specific goals. It’s also possible to alternate carb intake on a weekly or monthly basis, again depending on someone’s goals.

Carb cycling diets have been popular among bodybuilders, fitness models and certain types of athletes for decades. What makes carbs so special? Carbohydrates are the body’s first source of fuel, since they’re easily turned into glucose and glycogen, which feed your cells and helps create ATP (energy).

Your metabolism rises and falls based on your consumption of calories and different macronutrients, including carbohydrates. And some studies have found that adequate carb intake improves performance in both prolonged, low-intensity and short, high-intensity exercises. Consuming carbs in the right amounts can also help to control your appetite, increase satiety and prevent feelings of deprivation long-term.

Although every carb cycling diet plan is different and needs to be customized based on whether weight loss or muscle gain is the primary goal, most carb cycling diets build in about one to three days per week when you can consume more carb-heavy foods (like potatoes or grains).

What types of things do you eat when you’re not boosting your carb intake? On lower-carb days, foods like non-starchy veggies, grass-fed meats, eggs and healthy fats are the base of your meals.

Some carb cycling diet plans also include a “cheat day” for indulging on some decadent foods in order to reward yourself for your commitment, guilt-free.

Related: Reverse Dieting: Does It Help or Hurt Weight Loss?

Is Carb Cycling for Women Healthy?

Very low-carb diets, especially when followed for an extended period of time, are not always a good fit for everyone — including women with hormonal imbalances, those with thyroid disorders, people who are already underweight, and some people who are very athletic.

Some question whether it’s necessarily a good idea for women to try low carb diets, including the keto diet, given the fact that women’s hormones tend to be more sensitive to most dietary and lifestyle changes. This is due to the sensitivity of the hypothalamic-pituitary-adrenal [HPA] axis system, which responds to stress, including calorie/carb restriction.

However, there’s evidence that low-carb diets and carb cycling can help women when done right, especially those in perimenopause or menopause, to achieve weight loss, improved blood sugar control, better quality sleep and reduced menopause symptoms like hot flashes or night sweats.

Women can benefit from carb cycling because this approach may help prevent hormonal issues tied to low leptin levels and low calorie intake, such as decreased estrogen production and thyroid issues like hypothyroidism. Cyclical eating may also help prevent long-term reductions in resting energy expenditure among women according to some studies.

One recommended approach for women is to work towards a plan that involves eating low carb (perhaps while also doing intermittent fasting) on 2–3 nonconsecutive days per week (e.g. Tuesday, Thursday and Saturday). Stick to only light exercise or yoga on low-carb and fasting days to reduce feeling exhausted or hungry, keeping higher intensity activities for your non-fasting days. This approach allows for more dietary and lifestyle “moderation” because the goal isn’t to eat 100 percent “perfectly” all the time.

Another way for women to improve their results when carb cycling is to focus on eating alkalizing, nutrient-dense foods, low-carb foods like avocado, dark leafy greens, other non-starchy veggies, fermented foods, clean protein sources, etc. An alkaline diet is one that includes whole foods that have positive effects on pH levels of the blood and urine by lowering acidity. A low-carb alkaline diet benefits women by promoting weight loss, detoxification, heart health, stronger bones, decreased inflammation and reversal of nutrient deficiencies.

Health Benefits

Why would someone choose to carb cycle instead of just dieting the old-fashioned way? Some the advantages that a carb cycling diet has include:

• preserving muscle mass and preventing muscle wasting
• helping muscle recovery after workouts
• boosting weight loss or reducing body fat percentage
• preventing a dip in your metabolic rate by increasing leptin levels; according to one study, a three-day carbohydrate overfeeding plan boosted leptin and 24-hour energy expenditure, but a three-day fat overfeeding plan did not
• including flexibility and a variety of healthy foods
• allowing you to keep your favorite meals as part of your plan
• giving you more energy
• preventing extreme hunger or fatigue
• helping to prevent hormone imbalances

Here’s more about the main benefits associated with following a carb cycling diet:

1. Helps Build and Preserve Lean Muscle Mass

Strength training and other forms of resistance exercise actually break down muscle tissue, only to make it grow back stronger. The process of rebuilding and repairing muscle tissue takes a lot of energy, and once again your body requires some of its primary fuel source (carbs) to do this. This is known as the post-workout anabolic window.

Insulin regulates amino acid and glucose entry into muscle cells following higher carbohydrate intake, which has important anabolic effects. According to findings from a 2013 study published in Journal of the International Society of Sports Nutrition, carbs help restore your energy and provide muscles with glucose for rebuilding or glycogen to be stored for future energy. That being said, ketones can also serve as a fuel source when dietary carbohydrate is restricted, which could be of benefit for some athletes — which is why cycling works well for many.

“How many calories should I eat a day?” If you don’t consume enough calories and carbohydrates following resistance training, you may “starve” your muscles of the fuel they need to grow back bigger and stronger. For this reason, many people focused on building muscle choose to have higher carb days after tough workouts. Eating at least moderate amounts of carbs may also help with physical performance long-term, according to some studies.

Simply restricting calories and working out more can take a toll on your metabolism and even have the opposite effect of what you’d like — leaving you weaker, fatigued and unable to consume as many calories without gaining weight. Alternating days of higher vs. lower carb intake, especially when timed around workouts, is beneficial for cutting your body fat percentage down while still not sacrificing your muscle mass. And keep in mind you want to hold on to all the muscle mass you can, since this is what keeps you burning calories at a healthy rate even into older age.

2. May Help Prevent Your Metabolic Rate From Slowing Down

In one study, when 74 adults followed a “calorie shifting diet” (in which carbs also increased and decreased) for six weeks, their resting metabolic rate tended to remain unchanged. They also experienced a decrease in plasma glucose, total cholesterol and triacylglycerol. Feelings of hunger decreased and satisfaction increased among those on the calorie shifting plan more so than those on the “classic calorie restriction diet.”

3. Encourages Maintenance of a Healthy Weight

Is carb cycling good for weight loss? It certainly can be. One of the primary benefit of a carb cycling diet is that it supports and possibly even speeds up weight loss while still preserving and even building lean muscle mass. When it comes to improving body composition, this is the gold standard because it keeps your metabolism running efficiently and allows you to maintain your weight more easily long-term.

When you enter into a “carb deficit,” meaning you take in less carbs than your body needs, you encourage weight loss because your body begins to burn stored fat for fuel. Cutting carbs very low, and following plans like the ketogenic diet or Atkins, works for many people to improve certain health conditions and help them reach a healthy weight. But for others, it’s difficult to sustain and actually can slow down the metabolism when followed long-term due to hormonal changes.

Carb cycling is one way to prevent weight regain and reduced motivation — plus carb cycling for weight loss can be effective in both the short-term (giving you quick results and energy) and long-term.

4. Encourages You to Eat More Plant Foods

Carbohydrates are the primary type of macronutrient found in most plant foods, although exactly how many carbs a plant food has depends on the specific type. Whole foods that are higher in carbs, such as sweet potatoes and other root veggies, beans/legumes, and fruit, are often encouraged on higher carb days.

Some of the healthiest foods in the world — such as leafy green veggies, cruciferous veggies, artichokes, asparagus, sea veggies, herbs and spices, for example — are actually pretty low in carbohydrates and therefore suitable for both high-carb and low-carb days.

A bonus of eating these foods is that they contain plenty of dietary fiber and antioxidants. Fiber has many benefits, including helping make you feel full and reach satiety, while antioxidants fight free radical damage and slow the effects of aging. A healthy carb cycle diet plan does more than boost protein intake and vary carbs — it also teaches you how to incorporate essential foods into your meals in ways you actually enjoy.

5. Helps You Stick with Healthy Eating Long-Term

While it’s possible to lose weight following other diet plans that restrict overall calories, many find that carb cycling works faster and involves fewer feelings of deprivation.

Because things like grains, fruit and legumes are included at least one to three times per week while carb cycling (sometimes also along with a “cheat meal”), there’s more flexibility with a carb cycling diet compared to other diets, which can encourage people to stick with it.

6. Can Help Reduce Hormonal Fluctuations and Blood Sugar Swings

There’s lots of evidence showing that a low-carb diet can be part of a natural diabetes treatment plan, as it’s an effective tool for patients with type 2 diabetes. Eating low carb has been shown to help improve blood glucose more than low fat diets in certain studies, and also to help regulate blood lipid, BMI, and decrease insulin doses in patients with diabetes.

Because it can reduce overeating, especially of empty calories and junk foods, lower-carb diet approaches can also help lower risks for diabetes complications and related risk factors like obesity or heart disease.

Why does cutting carbs on certain days improve blood sugar and hormone levels? Low-carbohydrate diets encourage improvements in dyslipidemia, diabetes and metabolic syndrome, as well as control of blood pressure, postprandial glycemia and insulin secretion.

Boosting carb intake, and calorie intake in general, periodically may also protect against declining levels of other key hormones, including thyroid hormone, estrogen, progesterone and testosterone. These hormones that are needed to keep your metabolic rate up and for many other functions. Dieting/calorie restriction (especially when combined with intense exercise) has been shown to lower production of these hormones in some people more than others, meaning that some are more susceptible to diet-induced hormonal changes based on factors like genetics.

Can You Do Carb Cycling for Keto?

• The keto diet is a very low-carb diet, or what some people even call the “no-carb diet.” People following a keto diet plan begin burning fat for fuel instead of carbohydrates. This happens when someone enters the metabolic state called nutritional ketosis, in which the body produces ketone bodies to serve as an alternative energy source.
• Most keto diets reduce net carbs to about 30 to 50 grams per day or less. This can be very advantageous for reducing hunger, cutting out junk carb foods, slimming you down and even reducing symptoms of many inflammatory diseases (like cancer and diabetes). Some studies show that some athletes even experience improvements in energy and performance when following a keto diet.
• If you find it difficult to stick to a very low-carb diet every day, especially for months on end, you might want to consider a carb-cycling diet instead, also called a cyclical ketogenic diet. A cyclical ketogenic diet increases carbohydrate intake (and sometimes calories in general) usually about 1–2 times per week (such as on weekends) to help mitigate side effects.
• Is it possible to carb cycle and stay in ketosis? Following a cyclical plan will result in you moving in and out of ketosis, but this isn’t a bad thing. In fact, it has metabolic benefits and can be psychologically rewarding, too, since it increases food flexibility.
• When doing a cyclical keto diet, some experts advise checking your urinary ketone levels (using ketone strips) and aiming for testing positively for ketones about three days per week.

Carb Cycling Diet vs. Keto Diet vs. Low-Carb Diet

• A carbohydrate-restrictive diet generally constitutes getting less than 30 percent of daily calories from carbohydrate food-sources (approximating <130 g/day).
• Is low carb or carb cycling better? This really comes down to preference, since both can be beneficial.
• Keeping carbs in your diet on intermittent days can help offset low carb side effects, although it’s possible that this will slow down weight loss a bit too. If you’re looking for fast results in terms of weight loss, reduced inflammation and more, then the keto diet may be your best bet. However, if you’re interested in a low-carb diet plan that is maintainable for many years, a cyclical diet is an excellent option.
• High-protein, low-carb diets (such as the Atkins diet) became increasingly popular in the 1990s as they gained lots of attention for causing rapid weight loss. While they are usually effective as promoting fat loss, the biggest disadvantage to low-carb diets is that for some they can be hard to sustain, meaning lost weight may come back as soon as someone resorts back to their old ways of eating. Some low-carb diets can also cause digestive problems, especially if the diet doesn’t focus enough on consumption of a generally healthy diet that includes enough high-fiber foods.
• One possible advantage of a carb cycling diet over low-carb diets or ketogenic diets is that “going very low carb” might increase fatigue and irritability in some people — a side effect that has been nicknamed “the keto flu.” However, this is usually the case when cutting back carbs dramatically to just about 5 percent to 10 percent of total calories.

How to Carb Cycle

Now that you know why to try a carb cycle diet, how do you carb cycle?

The difference in your carb intake throughout the week means you alternate lower-carb days with higher-carb days. Remember that eating more carbs and calories gives you a metabolic boost, while doing the opposite slows your metabolic rate down. However, cutting carbs and calories some days is what allows for weight loss.

Many people also like to incorporate specific meal timing into their carb cycling diet plans. Some choose to eat more frequently (four to six times per day) because it helps them stick with their plans and might offer some metabolic advantages. Others like to incorporate aspects of intermittent fasting for quicker results, such as only eating twice daily (skipping breakfast entirely).

Carb Cycling Schedule

Although there’s room for customization, here’s an example of a typical carb cycling diet meal plan:

• Monday: higher-carb day
• Tuesday: lower-carb day
• Wednesday: higher-carb day
• Thursday: lower-carb day
• Friday: lower-carb day
• Saturday: higher-carb day/optional reward day where you enjoy a favorite meal “off plan”
• Sunday: lower-carb day

*Consider having higher carb intake days on training/exercise days and lower carb intake days on rest days.

Another way of doing carb-cycling is having a “re-feed” day each week, or a planned increase in calorie intake that lasts about 8–12 hours. Re-feed days usually involve a substantial increase in carbohydrates. Typically they are done no more than once weekly, or sometimes only 1–2 times per month.

Carb Cycling Tips

• At first, don’t take on more changes than you can handle. Get accustomed to cycling, then consider experimenting with fasting once you’re more comfortable with the dietary changes you’re making.
• To sustain muscle mass and further improve your body’s ability to use carbs and calories, incorporate strength training into your exercise routine. Ideally do a combination of aerobic and resistance training every week, since both have major health advantages.
• To keep your metabolism thriving and boost digestive health, consider also taking some beneficial supplements. Recommendations include omega-3 fatty acids to lower inflammation, probiotics to help improve gut health, magnesium to help you recover from workouts, adaptogen herbs to help your body handle stress, and a high-quality multivitamin to make sure you meet your needs.
• Get enough sleep and manage daily stress. Both a lack of sleep and high levels of emotional stress can contribute to overeating, hormonal imbalances, weight gain and even poor immune function.

Carb Cycling Meal Plan

• How many carbs and calories should you aim for on high carb days?  This depends on your specific body type, gender, age, level of activity and goals. Women usually stick within the 1,500—2,300 calorie range throughout the week, while men typically stay within a range of about 1,500—3,000 calories.  Assuming you are somewhat active, try not to eat any less than about 1,500 calories daily. This can trigger a drastic metabolic slowdown and leave you feeling overly hungry and sluggish.
• Your carb cycling results will depend on how often you “cheat” and your typical calorie intake. You might find carb cycling to be easiest to sustain if you add or decrease only about 400—600 calories between high-carb and low-carb days.
• Higher-carb days might include 200—300 grams of carbohydrates, while lower-carb days might include 75—150 grams (sometimes even as little as 50). Once again, men who are bigger and more active tend to require more of both calories and carbs than smaller women do.
• Studies focused on the effects of nutrition for body composition changes show that on both days, your protein intake in grams should stay roughly the same, but fat intake will likely increase or decrease. On higher-carb days, fat might decrease to only about 15 percent to 25 percent of calories.
• How do you calculate macros for carb cycling? One gram of protein and one gram of carbohydrates both contain about 4 calories, and a gram of fat contains about 9. To figure out how many carbs you need divide the total number of calories you’re aiming to eat by 4 to get the number of grams of carbs you should eat every day.
• Always eat breakfast, including some protein and fiber to help keep you full.
• Eat lots of high-volume, nutrient-dense foods no matter what type of carb day it is. Load up on filling, healthy foods like leafy greens, other non-starchy veggies, clean protein, and healthy fats like avocado, olive oil and coconut oil.
• Avoid drinking calories, especially if weight loss is your goal. Drink mostly plain water, herbal tea, unsweetened coffee, etc.

High-Carb Foods vs. Low-Carb/No-Carb, High-Protein Foods

• The healthiest higher-carb foods to include in your meals are those that are complex carbs and unprocessed, such as: sweet potatoes; ancient grains (ideally sprouted) like oats, quinoa, buckwheat, amaranth and brown rice; whole fruits; beans and legumes; and natural sweeteners in moderation like raw honey.
• Because they’re loaded with junk, very high in calories and essentially bankrupt in terms of nutrients, it’s best to avoid processed high-carb foods, including those made with white flour or wheat flour products, added table sugar, conventional dairy, bread and other processed grains like pasta, sweetened snacks like cookies and cakes, most boxed cereals, sweetened drinks, ice cream, and pizza.
• Other healthy sources of carbs, which are lower in carbs than those described above but still provide some carbs, include vegetables like mushrooms, tomatoes, carrots, broccoli, cabbage, Brussels sprouts, spinach, kale, sea veggies, peppers, etc.
• Healthy food choices that are high in protein but low-carb or no-carb include grass-fed meat, pasture-raised poultry, cage-free eggs, protein powder made from bone broth, wild-caught fish, organ meats and raw dairy products, such as raw goat cheese.
• Healthy fats, which are also low-carb or no-carb, include olive oil, coconut oil, grass-fed butter, palm oil, nuts and seeds.

Risk and Side Effects

If a carb cycling meal plan is very different than what you’re accustomed to, expect that your body (cravings, energy, fluid levels, etc.) will take some time to adjust. You might experience some of the following effects when you begin carb cycling — but not to worry since most consider these to be “normal” and likely to go away within one to two weeks:

• Feeling more tired than usual
• Craving carbs at times
• Constipation or bloating due to water retention (especially after higher carb days)
• Feeling weaker during workouts
• Having trouble sleeping
• Being moody or irritable

If these side effects last more than one or two weeks, carb cycling might not be a good fit for you. Everyone is different when it comes to the reaction to different eating plans. Factors like someone’s age, gender, level of activity, bodyweight and genetic disposition all affect how that person feels when following a low-carb diet. Always listen to your body and use your best judgment instead of just following someone else’s advice.

Related: What Is the Slow Carb Diet? Potential Benefits for Weight Loss & More

Final Thoughts

• What is carb cycling? A carb cycling diet involves alternating lower-carb days with higher-carb days. Many carb cycling meal plans also boost calorie intake on higher-carb days, and then reduce calories on lower-carb days (in other words, intermittent fasting may be involved).
• Carb cycling benefits include building or retaining lean muscle mass, improving workout performance, encouraging weight or fat loss, giving you more energy, and preventing weight loss plateaus due to a slowed metabolism.
• Is low carb or carb cycling better? This depends on your preference and lifestyle. Carb cycling can be beneficial for muscle gain, physical performance, mitigating low carb side effects, and giving you more flexibility with food choices, which all make healthy eating feel more sustainable long-term.
• To get the most from carb cycling, focus on eating a healthy diet first and foremost, eliminate empty calories and packaged foods, and reduce your carbohydrate intake on about three to four days of the week, sticking to about 75—150 grams of carbs or less.