Erika Straus used to consider herself one of those lucky people who can eat whatever they want and not gain weight. So, naturally, she did — filling up on pasta, pizza and other dorm life staples while maintaining her fit figure. But when the then-college rugby player hurt her knees and stopped exercising regularly, she realized her luck had run out.

“I had all of these bad habits and gained 40 pounds” as a result, says Straus, now a 25-year-old opera singer in the District of Columbia, who also runs District CrossFit’s social media and marketing efforts.

After a few unsuccessful weight loss attempts and some internet research, she decided to try carb cycling, a strategy that promotes eating a very low-carbohydrate diet some days and a carbohydrate-rich diet on other days. To Straus, who loves pasta, the plan seemed far more bearable than following an entirely low- or no-carb diet all the time. The reality, however, was different.

“I’d go off carbs for two days, then have a meal with carbs and I would just overdo it,” Straus says. After a few months, she gained even more weight, quit the plan and continued to pack on pounds. “I didn’t necessarily believe it was possible to get in the best shape of your life in a healthy way,” she says.

[See: 7 Diet Mistakes Sabotaging Your Weight Loss.]

That all changed last spring when Straus moved to the District of Columbia, began biking to work and joined CrossFit, where she saw people carb cycling — and succeeding. So she decided to try it again, but with a different approach. This time, instead of bingeing on pasta on her carb-heavy days, she eats quinoa, brown rice or beans. Instead of haphazardly planning her low- and high-carb days, she aligns them with her workout schedule. Instead of leaving her eating choices to chance, she cooks batches of vegetables, chicken and hard-boiled eggs. And, instead of gaining weight, she’s flattened her belly, thinned her face and neck and watched muscle definition emerge. “I’ve already seen things that I did not see before,” she says.

What Is Carb Cycling?

Carb cycling — which isn’t a “diet” so much as a concept that emphasizes when you eat certain foods — seems to have originated among bodybuilders, fitness models and elite athletes trying to achieve peak performance. The idea was that by starving the body of carbohydrates, they’d improve its ability to increase glucose, or the stored form of carbohydrate energy, later. Then, when they ate large amounts of carbohydrates before competition, they’d soar.

“For example, sprinters [wanted] to see if they could tap into that extra stored form of glucose or energy even for an extra second longer, which would improve their times,” says Jessica Crandall, a registered dietitian in Denver who works with athletes.

But while the jury is still out on whether carb cycling actually works for that purpose, the eating pattern has nonetheless made its way into more mainstream circles like CrossFit gyms, social media posts and diet books, which mostly highlight carb cycling as a way to lose fat while building muscle.

“The way I describe it is: You need carbs to sustain activity levels, but until you’re at 10 percent body fat or below [for men], you might as well burn your body fat as fuel and teach your body how to do it well,” says Jim Loperfido, founder of Solace New York, who’s been using variations of carb cycling for nearly four years.

But whether carb cycling works to lose weight or improve body composition is debated, too. On one hand, you’re likely to lose weight, at least at the beginning, since carbohydrates hold onto water and cutting them out periodically can shed water weight, says Jim White, a registered dietitian and personal trainer with studios in Virginia. “That tends to motivate people,” he says. Some also find carb cycling is more reasonable and nutritionally balanced than diets that eliminate carbs entirely or require followers to obsessively count calories. “I’m just living life and eating what feels good,” Straus says.

[See: Should You Count Calories or Track Macronutrients?]

On the other hand, carb cycling isn’t safe or effective for everyone. Here’s what experts suggest considering before giving it a shot:

1. Know the risks.

If you have diabetes, heart disease or any type of metabolic syndrome, steer clear of carb cycling or any diet that restricts healthy carbohydrates. Women, too, should be cautious about trying carb cycling since their bodies need more fat than men, Loperfido says. Anyone can experience negative side effects like irritability, lack of energy and moodiness from carb cycling, too. “I’ve heard it hasn’t worked for [people who’ve tried it] because they can’t deal with those ups and downs,” Crandall says.

If you’re carb cycling to boost athletic performance, keep in mind that novelty can backfire, “You would never train out your tennis shoes on your marathon day, so putting a different fuel source in your body on marathon day may completely ruin how you feel during that run,” Crandall says.

2. Consider your activity level.

Carb cycling doesn’t just mean eating lots of carbs one day and few or none the next. While plans vary in exactly how many grams of carbohydrates you eat on how many days of the week, the point is to match your high-carbohydrate days with your most active days. If you don’t exercise, the plan might not make sense for you.

3. Eat smartly.

As Straus learned, portion sizes, carbohydrate sources and patience all still matter. “Healthy weight loss and good body change is not going to happen overnight,” she says. It’s also important to keep your overall calorie intake relatively stable, White says. “By decreasing carbs and restricting that, when you load up on carbs, people are going overboard and binge eat,” he says. “It can lead to binge eating disorders.”

[See: 11 Things to Tell Yourself When You’re About to Binge Eat.]

4. Talk to a pro.

Before starting a carb cycling plan, recruit the guidance of a registered dietitian or personal trainer with expertise in nutrition, who can make sure you’re following it in a way that meets your nutrient and energy needs. “If it’s a jump-start and you get that psychological edge, why not try it out?” White says. “But if it’s harmful for health and body, it’s not worth the risk.” Ultimately, Crandall adds, the pattern was never meant for weight loss or long-term use. “Do what you know you can do,” she tells clients, “instead of reaching for something you can’t adhere to long-term.”

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Should You Try Carb Cycling for Weight Loss? originally appeared on usnews.com