Despite their tarnished reputation, carbohydrates are an important part of any balanced diet. "Your body uses carbohydrates to make glucose, which is your body’s main energy source," says Tanya Rosen, nutritionist for Teasane and owner of Nutrition by Tanya. She explains that the macronutrient is vital for keeping energy levels up and powering you through your day—the problem is where they come from and how many are consumed.
Enter, the carb-cycling diet, a weight loss meal plan that suggests eating more carbs on certain days while cutting carb intake on others. In order to determine exactly how this diet works and whether or not it's good for you, we tapped Rosen to shed some light on the subject. Ahead, she breaks down everything you need to know before considering trying a carb-cycling diet.
Before discussing the carb-cycling diet, it's important to gain a better understanding of carbohydrates themselves. Rosen explains that the glucose made in the body thanks to carbs is a type of sugar that can either be used right away or stored for later. This is of the utmost importance to your brain, which relies on the energy created by carbohydrates to function. Additionally, carbs aid in the fat metabolism process, in which fats are broken down to provide additional energy.
Clearly, carbohydrates are vital to proper nutrition but serving size and sources can affect how beneficial carbs really are. "The dietary guidelines for Americans recommend that your carbohydrates make up 45% to 65% of your total daily calories," says Rosen. The equals out to about 225 to 325 grams of carbs each day. The best foods to eat in order to meet this daily recommendation are fruits, vegetables, oatmeal, legumes, and sweet potatoes, according to Rosen.
Carb-cycling diets vary depending on each person's individual goal, but most entail one to three days a week of high-carb consumption with low-carb intake on the remaining days, according to Josh Axe, MD. So a typical carb-cycling diet meal plan might include three high-carb days, in which you consume 200 to 300 grams of carbohydrates, and four low-carb days, in which you eat just 75 to 150 grams of carbs. This is thought to help build muscle and promote weight loss without heavily restricting what you can and cannot eat or causing hormone imbalances.
"The higher-calorie, higher-carb days are supposed to positively impact hormones that affect energy expenditure and muscle protein metabolism, including testosterone, insulin, and cortisol," explains Rosen. These days might also help maintain workout intensity by allowing the body to refill its glycogen stores. Conversely, "the lower calorie and low carb days are meant to rev up fat burning," she says.
According to Rosen, a carb cycling diet may be efficient in terms of weight loss, but it's not necessarily sustainable. "Any low-calorie or low-carb diet will make you lose weight," she says. "The reason people see such a big difference is because the amount of carbs you eat greatly affects how much water your body retains, so when you restrict your carb intake, you can shed a significant amount of water and glycogen weight."
Unfortunately, cutting water weight is not the same as actually shedding fat, which is ideal when it comes to meeting health goals. Additionally, simply cutting carbs won't help you build muscle. "Regarding maintaining and or building lean muscle mass, that can only happen if one eats a large amount of protein," Rosen says.
It seems as though focusing on the quality of what you eat is the most important aspect of any healthy diet. In this case, carb cycling may help you quickly lose weight, but you'll want to be sure to eat enough protein to build muscle with exercise and to consume carbohydrates from sources like fruits, vegetables, and legumes for sustainable energy.