Is Carb Cycling an Effective Eating Strategy?

How to Eat Carbohydrates and Lose Weight

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Adjusting your carbohydrate intake may be used as a strategy to enhance weight loss, muscle gain, or athletic performance. The idea of timing your consumption to eat "just the right amount of carbs at the right time" has been a topic of interest in the fitness world for decades. How can you effectively take advantage of the science behind carb cycling without falling prey to dangerous, overly restrictive, or useless dieting practices?

Confusion about the role of carbohydrates during weight loss often stems from 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.

Carb cycling has been popular among bodybuilders and athletes for some time. The principles of carb cycling can be an effective way to improve your health and support an active lifestyle. However, the extreme weight loss associated with carb cycling and some sports is not always in line with achieving better health.

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 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. Depending on the type of sport you participate in, your nutritional needs will vary. A marathon runner may 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 you try carb cycling, you must 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. General guidelines are as follows:

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

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

The 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 after which you'll choose one day to consume significantly more carbohydrates (and exercise). "Refeeds" are used as breaks from low carb eating. Going for longer 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.

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, 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.

Efficacy

A well-developed carb cycling plan, done for a short duration of time, can be effective, according to Maloney. With any nutrition plan, the overall goal should be consuming quality whole foods, while limiting processed foods and sugars.

When the carb cycling program includes a calorie deficit, it is likely to promote weight loss. Like all eating plans, carb cycling requires periodic re-evaluation and adjustment to ensure that it is still providing the intended health benefits.

High carb days help offset the body from adapting to the program by boosting leptin levels and feelings of satiety. Increasing carbs refuels the muscles, boosts metabolism, and improves training ability.

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.

That said, the "all-or-nothing" approach associated with cheat meals and strict dieting is not advised for overall health and wellness. Focusing on healthy food to fuel your fitness, rather than fighting against your body, is a more positive way to frame a sustainable training and nutrition program.

Is It for Everyone?

Carb cycling can be for most people if used properly and for a short amount of time, according to Maloney.

Because the program requires strict adherence, it may not be the best way to develop day-to-day healthy eating habits. Start with simpler methods to improve your food choices before jumping into carb cycling. Consuming a variety of fruits, vegetables, and natural protein foods, while reducing processed foods and sugar, are some ways to get started with eating healthier.

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

Carb cycling may be an effective way to make weight loss easier.

There is an important and significant link between carbohydrate intake and blood-insulin levels, says Maloney. 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.

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).

As with any weight loss strategy, healthy eating should be the foundation of your nutrition plan. Cycling your intake of carbohydrates can be a great way to lose weight and body fat as long as the strategy is followed appropriately, according to Maloney.

Carb cycling should never become an excuse to binge and purge on unhealthy foods or to 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. Creating an energy surplus with more carbs can 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.

Protein intake should be higher for muscle growth when carb cycling, says Maloney. Protein should make up 30–35% of your daily caloric intake, which in turn can support muscle growth.

Carbohydrates during a low phase would account for 10–15% of intake and should consist mainly of fresh vegetables, suggests Maloney.

Higher carb days should be used 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. High carb refeeds can improve leptin levels, thyroid hormones, and boost testosterone.
  • 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. 

According to Maloney, there are a few pros and cons of carb cycling to consider.

Pros

  • Results are typical

  • Cycles can be pretty short which leads to success

  • Typically leads to better food choices overall

Cons

  • Strict planning and high adherence is necessary

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 needlessly complicated. 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. You may be surprised to find out that making progress towards your goals isn't as difficult as it seems.

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