We all remember the low-carb diet craze, which demonized carbohydrates in favor of high protein intake. Atkins-like diets helped people shed weight quickly, but were far from perfect. Some research suggested lower-carb diets could increase the risk of heart disease, and dieters often gained the weight right back after reintroducing carbs.
Now, carb cycling, a diet that alternates between high and low carb days, promises similar results, without depriving the body of any macronutrients. But can you have your cake and eat it too?
Believe it or not, the concept of carb cycling actually came from the bodybuilding industry, says personal trainer Heidi Powell, of ABC’s Extreme Weight Loss. They would bulk up while building muscle, then carb cycle to reduce their final layer of fat. Trainers caught on, and experimented to see if everyday people could manipulate their carb intake and get similar results.
After seeing how well it seemed to work, Powell started putting all her weight loss clients on carb cycling programs. She says they see dramatic changes as a result of the diet combined with exercise. Some research backs it too, including one British study that found that women who eliminated carbohydrate-rich foods twice a week (and ate their normal diet the rest of the time) lost an average of nine pounds over four months. Women on a 1,500-calorie Mediterranean diet, on the other hand, lost only five pounds in that time.
When a person pulls carbs from their diet for an extended period of time, they lose fat as well as a lot of water weight, explains Powell. But the longer they deprive themselves of carbs, the more they decrease their metabolism. Reintroducing carbs causes the body to rebound, holding onto every bit of carbs, sugar and water it can.
With carb cycling, the body is never deprived of carbs long enough to slow the metabolism, and is able to get into a catabolic fat burning state on the low carb days. Essentially, the high carb days act as “boost” days, increasing metabolism, and the low carb days act as “burn” days, when the body is an optimal state to burn fat.
The goal of carb cycling is to consume the most amount of carbohydrates possible while still making progress towards your goal, says Roger Lawson, C.S.C.S., a trainer at All-Access Fitness Academy in Shrewsbury, MA. The more intense a workout, the more carbohydrates will need to be ingested to fuel a session. But there’s a fine line between fueling up and impeding progress.
The “Classic Cycle,” a straightforward plan designed by Powell’s husband Chris (and featured in his book Choose to Lose: The 7-Day Carb Cycle Solution), alternates between low-carb and high-carb days, with the seventh day as a reward day. On the reward day, you can eat foods that may have been off-limits on other days. Psychologically speaking, Powell says including rewards is part of what makes some people so successful on the plan. “It helps them mentally and emotionally feel like they’re never deprived of foods they can’t have on a typical diet,” she says.
On this and other cycles, individuals will feel results in about a week, and start to see them in two weeks, says Powell. She recommends a 12-week cycle for the best physical and mental results, but says the principles of carb cycling can be followed for any phase of life, including weight loss, maintenance, fitness and performance.
The Fine Print
While no specific types of carbs are technically off-limits, the carbs should ideally come from unprocessed, whole foods such as rice, oats, potatoes, whole grains and breads, Lawson says.
Unlike their sugary counterparts, research suggests that healthy starches (or resistant starches) like grains, beans and legumes can help with weight loss by boosting metabolism. In one Australian study, rats that ate a diet low in resistant starch gained fat and lost muscle mass, while those that ate a diet higher in resistant starch preserved their muscle mass despite the higher carb intake. (Though, it’s not 100 percent clear whether the same holds true for humans.)
Another important thing to keep in mind is that carb cycling shouldn’t be a carb or junk food free-for-all, proponents advise. “But don’t fear bringing the occasional treat into the mix either, as long as is total carbohydrates are accounted for,” Lawson says.
Like any dietary strategy, carb cycling isn’t for everyone. And with the most current research having been done on mice, it might be a while before carb cycling can be recommended as a science-backed weight loss technique. But for healthy individuals willing and able to adjust their carb consumption according to fairly regimented guidelines, some experts suggest carb cycling can lead to positive body composition changes while still letting you enjoy dessert and a glass of wine from time to time.