The Y2K health fads making a comeback—and why to skip them
From detox diets to spot-reducing belly fat, some health fads just refuse to die. Here’s why these myths endure—and what science actually says about them.
When Margaret, 37, was a teenager in the early 2000s, she tried her first diet: the South Beach Diet, a low-carb plan heavy in calorie restriction. For the next 14 years, she had tried nearly every health fad in her “endless pursuit for thinness.” “I could have written a novel with the amount of time I spent thinking about the calories,” she says.
She wasn’t alone. The early 2000s were packed with extremes—juice cleanses that promised to “flush toxins,” 30-day ab challenges, and supermarket shelves full of low-fat products.
Two decades of research have since debunked these ideas. Yet the myths keep coming back—just dressed up as “wellness.”
“Over the years, [diet culture] has been rebranded in different ways to fit the way people think it's acceptable to talk,” says Traci Mann, a psychologist and the director of the Health and Eating Lab at the University of Minnesota.
When talk about calorie restriction and extreme weight loss became taboo, brands pivoted toward “clean eating,” “body recomposition,” and other terms that sound more wholesome. “Nothing has changed underneath, but the lingo does change from time to time,” Mann says.
And with the weight-loss market worth $7.7 billion in 2024—and projected to hit $11 billion by 2033—there’s plenty of incentive to keep the cycle going. But what does science say about them?
How diet myths reinvent themselves
Then: Atkins, South Beach, and Paleo banned bread, pasta—even fruit.
Now: Keto hacks and TikTok “no-carb” resets recycle the same promise.
Low-carb diets have gained popularity because they produce more rapid weight loss than other approaches. However, a 2022 meta-analysis found that low‑carb diets produced more weight loss than balanced diets for the first eight months, but by a year, the advantage disappears.
Research shows that whether you restrict calories (through carbs or fat), “our bodies adapt to a significant reduction in calories by metabolic change,” says Mann. Restrictions often backfire as the body adapts, slowing metabolism and making weight regain more likely.
However, some experts say that low-carb diets can be beneficial for those at risk of cardiovascular disease and diabetes. In most of these cases, study participants kept their carb intake to 50 and 129 grams per day while maintaining their normal daily calories. Experts stress: if you’re considering going low-carb, it’s best done under medical guidance to avoid falling into unhealthy restriction.
Then: Diet ads equated thinness with discipline.
Now: Fitness influencers frame thinness as a “lifestyle.”
In a culture obsessed with thinness, the weight-loss industry has long sold the illusion that success comes down to self-control. “The idea that anyone could take off as much weight as they want, and have whatever body they want, and if they fail at that, it's because of their own lack of willpower—it’s just not true,” says Mann.
(Losing weight leads to better health? Not necessarily.)
Research shows much of our ability to manage weight comes down to biology and genetics. Dieting shifts hunger hormones, making it harder—not easier—to resist food cues. Willpower has little to do with it.
Then: Lemon-juice cleanses and cayenne tonics promised to flush “toxins”
Now: Detox teas and pricey juice kits flood TikTok.
Detox diets promise to “cleanse” your system while trimming your waistline. But your body already has built-in detoxifiers: the liver and kidneys. According to the National Center for Complementary and Integrative Health, there’s no compelling research that diets can eliminate toxins or promote sustainable weight loss. Many detox products can even be harmful, leading to dehydration, electrolyte imbalances, or side effects in people with preexisting conditions.
Then: 30-day ab challenges claimed spot reducing fat is possible
Now: Social media workouts still push “belly fat burners” and “toned arm” routines
For decades, fitness magazines and influencers have pushed the idea that endless crunches or planks can burn belly fat. But fat loss doesn’t work like that. You can strengthen and grow specific muscles through exercise, but where you lose fat is dictated by genetics, hormones, and overall body composition.
Why do these myths still endure?
If the science is clear, why won’t these fads finally die?
“There’s always been a war on fatness in [the U.S.],” says Edie Stark, a licensed clinical social worker and eating disorder expert. For a while, the body positivity movement pushed back on those ideals, encouraging people to embrace different shapes and sizes—even if diet culture never entirely disappeared. But now, the idea of thinness-as-status has been revived by GLP-1 drugs that put weight loss back into the spotlight.
But Adrienne Bitar, a lecturer on the history and culture of American food and health at Cornell University and the author of Diet and the Disease of Civilization, says it’s not just about body image. “Diets and fads—I think of them as sort of like clay. They are modeled according to the anxieties of the time,” she says. “The detoxification diet, for example, is a pretty direct reflection of concerns about environmental toxins and pollution. It came out of a long tradition that critiques the so-called toxic food environment.”
What’s shifted is how quickly—and how widely—these myths can spread. In the early 2000s, fashion magazines and diet books were primarily responsible for spreading misinformation. Now, it’s TikTok and Instagram.
“Anyone can say anything on social media or call themselves a coach; there’s no fact-checking,” says Stark. And most viewers lack the media literacy to distinguish between marketing and science. Parasocial relationships with influencers only blur the line further, making sales pitches feel like friendly advice.
Even as the language shifts—from “low-fat” to “clean eating,” from “dieting” to “wellness”—the values underneath haven’t budged. Thinness is still equated with discipline, morality, and beauty.
What to do instead
Experts in nutrition and behavioral science agree: you don’t need a 30-day shred or a lemon-juice cleanse. The basics work best—and they’re sustainable. Move your body regularly (the Physical Activity Guidelines for Americans recommend 150 minutes of moderate exercise or 75 minutes of vigorous exercise per week), get enough sleep, manage stress, and eat a balanced diet. There are no quick fixes.
(How to choose a walking style that aligns with your fitness goals.)
Weight loss itself isn’t necessarily a bad goal, although experts stress it shouldn’t come at the expense of your mental health or lead to chronic restriction. Small shifts are often more effective than strict rules: keep less healthy foods out of easy reach, and make nutritious options more accessible. “Even if you have a bowl of candy across the room, you’re going to eat less than if that bowl is right at the table where you’re sitting,” Mann says.
More importantly, health and weight aren’t the same thing. “You don't have to lose weight to be healthy,” Mann adds. “It's actually easier to improve your health than it is to lose weight.”
For Margaret, separating the two was a transformative experience. Working with a Health At Every Size nutritionist and practicing intuitive eating, she relearned what it meant to enjoy food. “I was like Bambi learning to walk,” she says. “I would not have thought that I would be able to be at this level of peace with my body.”
