Carb Cycling Diet—What Is It? Does It Work?

By: Brierley Wright, M.S., R.D.  |  Monday, June 29, 2015
Carb cycling’s roots are in bodybuilding. But it’s easy enough for any average Joe to follow a carb-cycling diet, which is perhaps why it’s gone mainstream. When you cycle your carb intake, you vary how many carbs you eat throughout the week, with some days being low-carb (2½ to 5 servings) and others high-carb (10 to 20 servings). The thinking is that your low-carb days put you in a fat-burning state and eating high-carb boosts your metabolism.
As with most trendy diets, there are a few plans to choose from, but the gist is the same—most plans cut carbs and calories. For example, the 7-Day Carb Cycle Solution gives women 1,500 calories on high-carb days and 1,200 on low-carb days (men get 2,000 and 1,500 respectively).
Unfortunately, the research on intermittently restricting carbs is almost nil. There’s one 2013 study, however, published in the British Journal of Nutrition, that shows promise. When 33 overweight women ate a carb-cycling-type diet for 3 months they lost about 2¾ pounds more and burned significantly more fat than their 27 counterparts who simply cut calories. Interestingly, both groups ate the same number of total weekly calories, but how they met that target differed: the carb-cycling group cut their calories pretty heavily just 2 days a week and ate “normally” 5 days a week, while the other group cut their calories by 25 percent every day.
The Bottom Line
Any diet that cuts calories to these targets usually leads to weight loss. If you’re keen to slim down by cutting carbs, carb cycling may be an easier regime to follow than going low-carb for the long haul. More research is needed, though, to see if carb cycling is more effective long-term than other calorie-restricted styles of eating. If you give the diet a go, opt for good-quality carbs (whole-wheat bread, whole grains, etc.) and keep your “feast” days sensible.
Send your nutrition questions to Nutrition Editor Brierley Wright, M.S., R.D., at askus@eatingwell.com