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Nutritionists Grade Five Different Diet Fads For Runners

Nutritionists take on the most popular eating trends of the last 10 years and dole out grades. Which diets pass the test?

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From grapefruit to cabbage soup, crazy diets have been a thing for pretty much ever. Many of them “work”, if your only goal is dropping pounds. But for any gal who cares about her long-term health—and for runners in particular—it’s essential to get good nutrition 24/7. We’ve asked nutritionists to dish on which diets are safe for runners—and which ones should send us sprinting toward the hills.

Sugar Busters

Based on the best-seller Sugar Busters! Cut Sugar to Trim Fat, this diet is just like the name sounds: It recommends nixing sugar from all areas of your eating (including naturally occurring ones) and replacing with high-fiber foods.

No-no’s: Sweets (obviously), plus potatoes, pasta, white bread, white rice, corn or corn products, beets, turnips, parsnips or rutabagas

Okay: Sugar-free ice cream, soda and candy, as well as all artificial sweeteners, like Splenda and stevia

“I like this diet,” says registered sports nutritionist Azadeh Gharehgozlou, Ph.D, who supports eating high-glycemic foods, like white rice and white bread, in moderation only. Runners can get their carbs from healthy sources, such as bananas and berries. Unlimited calories mean your runs will be well fueled.

Juice Cleanses

In the past few years, juice cleanses have officially become trendy. And you’ve probably seen a co-worker or two toting a little cooler full of pricey bottles. Cleanse companies purport that drinking only liquid for a few days resets the system to kick-start weight loss while increasing energy levels.

No-no’s: Solid food or any juice that doesn’t come in the pre-packaged bottles

Okay: One juice every two to three hours, and unlimited water and herbal tea

“Trying to run or doing any workout while following a restricted detox plan can result in undesirable side effects,” Gharehgozlou says. Your body needs calories from real food to run! Gharehgozlou says a juice cleanse likely won’t do any harm if you stay off the streets—but it may not do you any good either, and it will empty your wallet. These cleanses run upwards of $100 per day!


This mega-popular diet was first published by Dr. Robert Atkins in 1981 but resurged in 2009, when it was repackaged as Dr. Atkins’ New Diet Revolution. The premise is that eating excessive carbs causes weight gain. The diet comprises four week-long phases: The first phase highly restricts carb consumption, and the following three progressively allow them back into the diet.

No-no’s: The first phase eliminates grains, fruit, dairy, nuts, seeds and beans. By the fourth week, you are back to eating most grains and low-sugar fruits.

Okay: Vegetables, meat, eggs, cheese and healthy fats during phase one. Most foods aside from sugar, simple carbs and processed foods are allowed by the end of the diet.

Richard D. Feinman, researcher at the SUNY Downstate Medical Center, says he believes Atkins is useful “as a focal point for teaching nutrition and metabolism.” Runners will still be able to get sufficient energy from lean meats and vegetables rather than grain products. There is no calorie restriction, so you can eat enough to maintain your energy—however, we don’t recommend trying this plan while doing high-mileage training or leading up to a big race.


Published in 2002 by Dr. Loren Cordain, The Paleo Diet is based on eating healthful foods from the Paleolithic era to the beginning of the agricultural revolution.

No-no’s: Dairy products, cereal grains, legumes, refined sugars and processed foods

Okay: Meats (grass-fed preferably), fish and seafood, fresh fruits, veggies, seeds, nuts and healthy oils, such as coconut, olive and avocado

“Every meal has an adequate amount of healthy meat combined with nourishing veggies or a reasonable amount of fruit,” says Gharehgozlou. For runners, this diet provides unlimited calories, energy from most fruits and vegetables, and healthy fats. You should have no problem staying energized and in great shape.


Otherwise known as Human Chorionic Gonadotropin, HCG is the hormone women make while pregnant. This diet claims you’ll burn fat from the absorption of the HCG hormone (taken as drops or injections). However, you can only ingest approximately 500 calories daily—an unhealthy amount at best.

No-no’s: Eating more than 500 calories per day

Okay: Any food that doesn’t take you over the strict limit

“Our brain adjusts on glucose to funtion normally, and 500 calories per day definitely is not sufficient,” says Gharehgozlou. If the daily injections don’t have long-term effects on your health (this has largely gone untested), the extreme calorie restriction will. Very low calorie diets often cause weight gain in the long term due to a negative impact on the metabolism.