Is Carb Cycling an Effective Eating Strategy?

How to Eat Carbohydrates and Lose Weight

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The idea of timing and limiting carb consumption to maximize energy, build muscle, and lose fat has been a topic of interest in the fitness world for decades. This approach is known as carb cycling and is used for many purposes, from boosting athletic performance to weight loss.

Achieving optimal results from carb cycling requires an understanding of the diet science involved, dedication to a specific eating plan tailored to your body and fitness goals, and awareness that this diet plan isn't right for everyone.

Common Misconceptions About Carbs

Much has been made in recent decades about the evils of eating too many carbohydrates. However, while overconsumption of carbs can result in weight gain and other health issues, carbs in moderation are not a villain—nor necessarily something to avoid.

Carbohydrates, along with fats and proteins, make up the human diet. Carbs, which are broken down into glucose by the body, are an essential source of energy and nutrition, which is especially important as a fuel for exercise. This is why elite athletes talk about "carbo-loading," power bars and the like exist, and carb cycling is popular among many bodybuilders and athletes.

Confusion about the role of carbohydrates during weight loss often stems from the dogma of restrictive diets, like Atkins or the Whole 30. While there may be some benefit to adjusting your carbohydrate intake, blindly eliminating carbs could potentially do you more harm than good. Learning how to incorporate a balanced amount of healthy carbohydrates can help you feel your best during training and periods of rest and recovery.

The principles of carb cycling can be an effective way to improve your health and support an active lifestyle. But in most cases can lead to decreased speed, stamina, and strength as carbohydrates are the primary source of energy for the body and energy in the form of glycogen stores.

However, the extreme weight loss associated with carb cycling and some sports is not always in line with achieving better health because the weight loss may be from the breakdown of glycogen stores that consist of water and carbohydrates along with lean body mass, or muscle.

What Is Carb Cycling?

Carb cycling is a high-level nutrition strategy that alternates between high and low intakes of carbohydrates. It requires strict adherence and should only be used in short duration phases, according to many nutrition experts, including Tony Maloney, an ACSM-certified exercise physiologist.

One of the goals of carb cycling is to force the body to use fat for fuel instead of glycogen (a form of stored carbohydrate). Performing exercise on low carb days can result in an increased ability to burn body fat for fuel once glycogen stores have been depleted. However, this cycling doesn't result in better performance. In addition, depending on the type of sport you participate in, carb cycling may not meet your nutritional needs. A marathon runner will likely fuel-up for a race differently from a sprinter, for instance.

There are several ways to carb cycle based on your individual goals. Phases of low and high carb days can help maximize how your body uses carbohydrates by eating more carbs on the days you are active and fewer carbs on rest days.

Before trying carb cycling, figure out how many baseline carbohydrates your body needs, which can be calculated by taking into consideration the following factors: 

  • Your age, weight, and height
  • Basal metabolic rate (BMR)
  • Activity level (sedentary, active, etc.)
  • Daily macronutrient breakdown (proteins/carbs/fats)

Typical carb cycling plans include high, medium, and low carb days. For athletes, high and medium intake during days you are training and low-carb intake on days you're resting. General guidelines are as follows:

  • For high-carb to medium-carb days, decrease baseline intake by 15–20%.
  • For medium-carb to low-carb days, decrease by another 20–25%.

Because carb cycling isn’t recommended for long-term weight management, you should only consider using it after exhausting more sustainable nutrition strategies, suggests Maloney. 

How It Works

The plan works by alternating carbohydrate intake levels throughout the week, and it puts the body in a caloric deficit on low carb days to promote weight loss.

The primary goal of carb cycling is to maximize the use of dietary carbs and stored glycogen. There are two common carb cycling schedules according to Maloney:

  • Infrequent large “re-feed” of carbohydrates in which you follow a low carb eating plan for seven to 14 days in a row. Then, you'll choose one day to consume significantly more carbohydrates and up exercise levels. "Refeeds" are used as breaks from low carb eating. Going for long stretches of time without carbohydrates pushes your body to adapt to using an alternate energy source (stored body fat). Once carbohydrates are depleted, your body relies on fat for fuel.
  • Frequent moderate re-feeds in which you incorporate one day of high carb eating every three to four days during an otherwise low carb phase. Some people also simply alternate high and low carb days.

Efficacy

Research shows that a well-developed carb cycling plan, done for a short duration of time, can be effective to boost athletic performance and lose weight. Carb cycling has become a popular way to overcome weight loss plateaus. It’s also a method that bodybuilders and athletes use to gain a competitive advantage.

The purpose of low carb days is to promote body fat utilization by improving insulin sensitivity. Insulin is a hormone used to absorb energy from carbohydrates. By temporarily reducing carbohydrate intake, we can help our bodies become more sensitive to the function of insulin.

High carb days are used to refuel your muscles, boost metabolism, enhance athletic performance, and improve appetite-regulating hormones like leptin and ghrelin. Leptin signals our brain when we feel full after eating while ghrelin is the hormone that signals hunger.

Like all eating plans, carb cycling requires periodic re-evaluation and adjustment to ensure that it is still providing the intended health benefits. Consulting with your physician or nutritionist to create an individualized plan is ideal.

As a form of carb cycling, some opt to incorporate "cheat" meals into an otherwise low carb eating plan. Although not as precise as traditional carb cycling, cheat meals can serve the purpose of boosting leptin levels and revving the metabolism, as well as to provide a motivational reward for following the more limited diet on other days. That said, the "all-or-nothing" approach associated with cheat meals and strict dieting is not advised for long-term health and wellness.

Is It for Everyone?

Carb cycling can work most people if used properly and for short periods of time. However, this is not a healthy diet for some people, such as those with diabetes or heart disease, people with eating disorders, or for pregnant or nursing women.

For someone struggling with prediabetes or diabetes, talking to your doctor about adjusting your carbohydrate intake may provide additional health benefits. That said, it's important to be careful about making sudden changes to your carbohydrate intake if you are taking certain medications for diabetes (like insulin).

Additionally, on low carb days, some people experience unpleasant side effects, such as fatigue, carb cravings, bloating, irritability, constipation, and sleep issues.

Because the program requires strict adherence, it may not be the best way to develop day-to-day healthy eating habits or work for people who prefer moderation. However, some gravitate to carb cycling precisely because it can feel like a middle ground between low and high carb diets, allowing the occasional high carb meals while reaping the benefits low carb eating has to offer.

Contact a licensed nutrition expert or registered dietitian who is familiar with carb cycling to see if this approach is right for you.

Carb Cycling and Weight Loss

Cycling your intake of carbohydrates can be a great way to lose weight and body fat, as long as portion control, patience, and the prescribed eating plan is followed.

Because the carb cycling program often includes a calorie deficit (as most people are less likely to over-consume fats and proteins), it is likely to promote weight loss. Additionally, there is an important and significant link between carbohydrate intake and blood-insulin levels. When insulin concentrations in the blood remain at a high level, fat storage is more likely. This can hinder weight loss and certain body composition goals. Carb cycling can help break this cycle.

As with any weight-loss strategy, healthy eating should be the foundation of your nutrition plan. Carb cycling should never become an excuse to binge or overly restrict your eating. Sometimes, the meticulous tracking required by a program like carb cycling can trigger disordered eating patterns. Check-in with yourself regularly to evaluate whether your current way of eating is serving you well.

Muscle Growth and Athletic Performance

Carb cycling is a popular nutrition strategy for bodybuilders and athletes. Physique competitors, in particular, depend on low or no carb days during the cutting phase of competition prep. Because glycogen contains a high percentage of water, manipulating carbohydrate intake can change the way muscles appear on stage by promoting temporary water weight loss. Creating an energy surplus with more carbs can also promote muscle gain.

Some athletes use carb cycling to optimize their muscle gain and minimize fat gain while training. This requires strict adherence to daily menus based on energy expenditure and body composition. Additionally, carb cycling programs may regulate how much protein and fat is being consumed as well.

For these athletes, protein intake will be higher (around 30–35% of your daily caloric intake) for muscle growth when carb cycling. Carbohydrates during a low phase would account for 10–15% of intake and should consist mainly of fresh vegetables. They also use higher carb days in conjunction with intense training days to supply more energy, help with muscle recovery, and provide essential nutrients.  

Health Benefits of Carb Cycling

Although further research is needed, many have attributed the following benefits to carb cycling:

  • Promotes weight loss: Low carb phases may suppress the appetite, making weight loss easier.
  • Enhances fat burning: Low carb days are said to shift the body into using body fat for fuel during exercise.
  • Improves muscle recovery: High carb days refuel muscle glycogen and supply essential nutrients to the body.
  • Boosts energy: High carb days provide quick energy for demanding workouts.
  • Regulates insulin and other hormones: Low carb days prevent blood sugar highs and lows. High carb days provide enough insulin to preserve muscle tissue and can improve leptin levels, thyroid hormones, and boost testosterone.
  • May promotes psychological well-being: Alternating low carb days with a high carb refeeds may feel less restrictive and more sustainable than eating low carb all the time.  

Pros and Cons

There is no such thing as a perfect way of eating. What works well for one person may not be the best fit for another. 

Pros
  • Positive results are typical

  • Short cycles can provide success

  • Typically leads to better food choices overall

Cons
  • Strict planning and high adherence is necessary

  • Not ideal for people with eating disorders

A Word From Verywell

While carb cycling may help with weight loss, muscle development, and health improvement, like other strict dietary approaches, it can be difficult to adhere to and feel overly restrictive. Depending on your goals and current fitness level, such detailed rules may not be necessary to achieve the results you desire. If you're trying to lose weight or get stronger, start by practicing mindful eating habits and incorporating resistance training into your routine. Additionally, consult with your doctor about the ideal individualized eating plan for you to use to reach your goals.

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Article Sources
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  1. Gejl KD, Thams LB, Hansen M, et al. No superior adaptations to carbohydrate periodization in elite endurance athletes. Med Sci Sports Exerc. 2017;49(12):2486-2497. doi:10.1249/MSS.0000000000001377

  2. Harvie M, Wright C, Pegington M, et al. The effect of intermittent energy and carbohydrate restriction v. daily energy restriction on weight loss and metabolic disease risk markers in overweight women. Br J Nutr. 2013;110(8):1534-47. doi:10.1017/S0007114513000792

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