Over the past decade or so, carbs have gotten a bad rap. A variety of fad diets and weight loss plans have demonized the macronutrient as an alleged source of weight gain, bloating, fatigue and more. In an effort to combat rising obesity rates in the U.S., many eating plans now severely limit the number of carbohydrates you consume.
But carbs aren’t all bad, and in fact, they provide the lion’s share of the energy your body can use right now to do all the things you need to do. The foods we eat are broken down by the digestive system. Carbs are converted to glycogen, which is the primary fuel cells use to generate energy to power our ability to do everything from think and type to running to catch the bus.
So how to get the optimal amount to maintain your ideal weight without lacking the energy you need to perform? Enter carbohydrate cycling, one way that people are trying to manipulate their intake of carbs in an effort to trigger weight loss and potentially reap other health benefits.
“Carb cycling involves planned increases and decreases in carbohydrate intake,” says Kacie Vavrek, a sports dietitian at the Ohio State University Wexner Medical Center in Columbus.
Carb cycling programs borrow from the world of competitive athletes who often fine-tune their nutrition leading up to competitions, says Toby Amidor, an award-winning nutrition expert and Wall Street Journal best-selling author of “The Best 3-Ingredient Cookbook.”
“Carbohydrate cycling has traditionally been used by endurance athletes (like marathon runners) in order to optimize energy. “The practice in athletes is eating more carbohydrates (like pasta and bread) on the days that include an intense physical workout and less carbs on days that require less activity.”
Some athletes also limit their carb intake during their training, but increase it just before the main event, a practice called carb-loading. This provides a surfeit of glycogen to be available to hard-working muscles on the day you need to perform.
“For non-athletes attempting to use carb cycling for weight control, carbs will be restricted on less active days and increased on exercise days,” Vavrek says.
The goal of carb cycling, Amidor says, is to “force the body to use fat as fuel instead of carbs in the form of glycogen.”
But this is sort of a free-form diet program, Vavrek says, noting that there are “no set guidelines; carb cycling can be done in different ways.”
One Approach to Carb Cycling
Lindsay Huelse, a retired nurse, fitness expert and creator of the Fitt Cycle App and method, has built her carb cycling approach on a two-day alternating pattern.
“It varies a little depending on the person’s specific biometrics, such as height and weight,” she explains, “but generally on the higher carb days, you’ll be eating 130 to 150 grams of carbs. On the lower carb days, we drop it down to about 40 or 50 grams of carbs.”
For reference, the average hamburger bun contains about 40 grams of carbs. A cup of strawberries contains about 12 grams of carbs, while a cup of broccoli has about half that amount, or 6 grams. And a cup of white rice contains about 45 carbs.
Huelse says a typical week on her Fitt Cycle plan will look like:
- 2 days of lower carbs.
- 2 days of higher carbs.
- 2 days of lower carbs.
- 1 day of higher carbs.
On the lower-carb days, “you’ll be primarily focused on high-protein or high-fat foods” to make up the calorie differences left behind when you remove carbohydrates.
A lower-carb day might have you eating:
- Breakfast: turkey sausage with egg whites.
- Lunch: filet mignon with asparagus and veggies.
- Dinner: baked salmon with avocado salsa.
Also on lower-carb days, Huelse says you’ll do more cardio workouts to help the body burn excess fat stores.
On a higher-carb day, your eating plan might include the following carbohydrates, along with plenty of vegetables, some healthy fats like avocado or olive oil, and some lean protein:
- Breakfast: a serving of fruit containing about 40 grams of carbs.
- Lunch: a sandwich with two pieces of bread that totals about 40 or 60 grams of carbs.
- Dinner: 4 ounces of brown rice.
Even on the higher-carb days, 130 to 150 grams of carbs is still a good bit lower than the average American consumes, which Huelse says is typically “well north of 200 grams of carbs per day,” so you’ll be continuing to encourage your body to burn fat for fuel with a lower carbohydrate intake.
Drawbacks of Carb Cycling
Huelse says there’s “not many risks with carb cycling unless your physician has you on a specific diet.” She recommends that you check with your doctor before starting this or any other diet plan.
However, Amidor and Vavrek don’t recommend using carb cycling and say there are some risks that can be associated with it. Amidor notes that “a dietary pattern limiting carbohydrates regularly over a long period of time can be low in nutrients,” such as:
These vital nutrients are typically found in foods like vegetables, fruit, whole grains and beans that, while typically higher in carbohydrates, are also rich sources of the vitamins and minerals your body needs to stay healthy. If you’re too restrictive in removing these sorts of healthful food items, that could “potentially lead to nutrient deficiencies,” Amidor adds.
In addition, the weight loss that’s associated with carb cycling might not be fat loss, meaning that it’s probably not sustainable for some people. Instead it may be water weight loss and loss of lean muscle mass, both of which are detrimental to supporting good metabolic function and overall health.
Indeed, Vavrek notes that “there’s no scientific evidence that links carb cycling to weight loss, improved athletic performance or to achieving body composition goals,” and it “doesn’t appear to have any benefit over any other types of diets for weight loss. If you lose weight via carb cycling, it’s likely due to the calorie deficit created when eliminating foods from the diet.”
Carb cycling can also cause side effects including:
Though Huelse says carb cycling can help you gain better control over blood sugar levels, Vavrek and Amidor both caution against people with diabetes or hypoglycemia using it because fluctuations in available glycogen may actually negatively impact your ability to manage blood sugars.
The Importance of Carbs
Amidor also notes that people who exercise regularly should avoid carb cycling. “Carbs are important for your body’s fluid balance, and eating too few carbs and exercising regularly can upset your body’s fluid balance,” potentially leading to dehydration or electrolyte imbalances.
In addition, Vavrek says that for some athletes who exercise regularly, carb cycling can actually decrease performance. “Carb cycling can negatively impact endurance, strength and speed as carbohydrates are our main fuel source for exercise, especially high-intensity exercise or stop-and-go sports. Carbs also play an important role in muscle synthesis,” meaning the repair phase after exercise that leads to gains in strength, endurance and muscle size.
And too few carbs can leave you feeling unable to complete those tough workouts. “If you’re trying to lose weight, exercise is certainly one key component. However, eating too few carbs can result in a lack of energy to exercise,” Amidor says.
Given these concerns, “I do not advocate this type of weight loss,” she says. “But if someone does want to use this technique, they should do so in conjunction with a registered dietitian nutritionist who can help guide them and ensure all their nutritional needs are met.”
Vavrek also does not recommend carb cycling, but notes that “some endurance athletes might benefit from this type of training.” However, she cautions that “some athletes will see decreases in performance with carb cycling,” and if you’re using carb cycling for athletic performance, it’s best to check in with a sports nutritionist for guidance and support.
Managing Carbs for Weight Loss
Instead of following a restrictive carb cycling program, consider taking a more moderate approach to dieting, Vavrek says. “A better strategy for non-athletes would be to follow a healthy, balanced diet and controlling the portion of starches to control calories while focusing on high-fiber sources (of carbs) like whole grains, beans, lentils and fruits and vegetables.”
Vegetables, fruit, beans and whole grains all contain carboyhdrates, but because they also supply vitamins, minerals and other important nutrients, they’re considered “good carbs,” versus the empty carbs that come from added sugar, candy, baked goods and soda.
Amidor adds that it’s certainly true that carbs can be easy to over-consume, “but they aren’t the enemy. Using measuring cups to help keep carb portions under control can help minimize overconsumption of foods like rice, cereal and other carbs.” While carbs are a form of sugar, they’re not all bad, and in order to have a well balanced diet, you need to include the highest quality ones you can in reasonable portion sizes.
Therefore, if you’re trying to lose weight, Amidor recommends being “selective with your carbs and opt for whole grains, fruit and other healthy carbs rather than eating empty carbs like cookies and cakes.”