Maybe don't bring the keto diet or juice cleanses into the new decade...


Honestly, 2019 was a damn good year for body positivity—more women than ever took to social media to celebrate their bodies, without trying to make them fit the standards of what society has taught them, oh, since the beginning of time.

But, despite some serious strides on the path to body acceptance, there were a few setbacks—mainly by way of some pretty problematic (and potentially even harmful) diets. That's right: While 2019 was the year of embracing cellulite (or, uh, "#celluLIT" according to Demi Lovato and Iskra Lawrence) and gushing over Ashley Graham's pregnancy photos, it was also another year of hardcore diets like keto and intermittent fasting.

keto meal steak
Raw beef steak with spices and herbs on wooden background
| Credit: Claudia Totir

Here, registered dietitians and trainers—experts in the health and wellness fields—divulge a few of the diets that had them rolling their eyes for most of 2019, and plead with everyone to pretty please leave these eating habits in 2019 where they belong.

1. Extreme Fasting

OMAD, 16:8, 5:2—whatever variation, fasting diets, or the practice of limiting your eating to certain hours of the day, or eating every other day, got tons of attention this year (primarily due to celebs like Jennifer Aniston swearing by the trend). But the practice of intermittent fasting isn't exactly practical for everyone—and may even be dangerous.

"I think the most dangerous diet trend of 2019 was extreme fasting," Abby Langer, RD, tells Health. "Eating only [a few] hours a day, or not at all on some days, is not normal by any means." Langer went on to explain that extreme fasting takes a toll on people physically, emotionally, and socially. After all, what are you supposed to do if you’ve got dinner with a friend at 7PM—but you’ve already finished your eating for the day? And there’s no science backing up these diets. “There’s no good research showing that eating that little can positively affect health,” Langer says.

2. The Snake Diet

The Snake Diet takes the idea of a fasting diet to the extreme, encouraging limiting your eating to as little as two hours a day, Health previously reported. To add insult to injury, the creator of the diet isn’t really qualified to be giving dietary advice, according to Cynthia Sass, MPH, MA, RD, CSSD. “The Snake Diet involves extreme fasting, and the creator, who is not a trained health professional, promotes incorrect information, such as the notion that obese people only need saltwater to meet their needs, because fat stores provide all the nutrition required.”

This can lead to serious health consequences such as malnutrition, Sass says. “The fact is anyone can become malnourished if they’re missing an adequate amount of vital nutrients day after day. Humans are not snakes, and we shouldn’t be mimicking their eating patterns.”

3. The Keto Diet

Keto fans (yep, we're looking at you, Jenna Jameson), you might need to sit down for this one. It turns out the high-fat, extremely low-carb diet might not be the best in terms of your long-term health. “Keto diets have a reputation right now of being ‘the most successful’ diet,” explains Amee Gloyn, RDN, CD.

But here's the thing: In this situation, "most successful" mainly means "leads to the most initial weight loss"—but the keto diet's "success" has nothing to do with overall health. “The truth is we have no more evidence that it works long-term better than any other diet.”

In fact, cutting back on one food group entirely—carbs, which include healthful foods like starchy vegetables and whole grains—isn't the safest way to go about losing weight. “Removing entire food groups—one(s) that our brain needs to properly function—is disordered [eating],” Gloyn says. Instead, if you're truly looking for sustainable weight loss, it's important to eat a variety of whole, nutritious foods—and not to deprive yourself of too much.

4. No-Carb Diet

J.Lo's abs weren't the only thing she made headlines for in 2019; she and fiancé A-Rod caused an uproar in January when the two started a 10-day "no-carb, no-sugar" challenge—much to the dismay of nutritionists everywhere.

"No thanks to J. Lo and A. Rod, this became a huge trend in 2019," Keri Gans, RDN, tells Health. "Carbohydrates, which break down into glucose, are our body’s main fuel source.” And our bodies can be seriously affected when we stop giving them carbs: “Our brain and our muscles cannot function optimally without glucose,” says Gans.

Instead, Gans hopes that in 2020, everyone learns the differences between “carbs that are better for you, such as fruits, veggies, and whole grains, versus those that aren’t," like overly processed ones like white bread or sugary cereals.

5. Gluten-Free Diets (when they're not medically necessary)

Some people—like those who have a gluten intolerance or celiac disease—very much need to avoid gluten because of the way their bodies negatively react to it. But for those don't have a medical need to remove gluten from their diets, going gluten-free isn't a good idea.

“Many people remove gluten from their diets due to a suspicion that they do not tolerate it," Alyssa Lavy, RD, tells Health. "However, removing gluten from your diet without first discussing this with your doctor may make it difficult to diagnose celiac disease and/or address the root cause of your symptoms."

Not only does going gluten-free cut out major food groups (hi, carbs) that provide nutrients to those who can tolerate them, but it's also a major lifestyle change, says Lavy. At the end of the day, cutting out entire groups of food simply isn’t your best bet unless you must do so for medical reasons.

6. Juice Cleanses

Please, can everyone stop with the juice cleanses already? Your body needs more than liquids to keep functioning properly. Performix House trainer Brittany Watts, NASM-CPT agrees: "Weight-loss juice cleanses have got to go," she says. "Not only are they not sustainable, but they actually do more harm than good. When you remove solids from your diet, you decrease your thermic effect of food (aka, the calories you burn) from the process of digestion.” This can cause your metabolism to slow down, which, if you’re trying to lose weight, will hinder your results.

Additionally, Watts says, if you do lose weight while on a juice cleanse, it can come right back when you start practicing your normal diet again. Still unconvinced? Earlier this year, Health reported on the case of a woman whose juice cleanse might have caused irreversible brain damage.

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