You’ve heard it in diet ads, anti-diet infographics, gym locker rooms, and possibly from us. “95% of diets fail” is one of the most repeated statistics in nutrition, and it gets used by both sides. Diet culture uses it to say everyone else’s diet fails, so buy theirs. Anti-diet spaces use it to say nothing works. So we went looking for where it came from.

The trail leads to a 1959 case series of 100 patients at a New York hospital. Each one got a diet sheet and one counseling visit, then never heard from anyone again. A quarter of them never came back. The number 95 doesn’t appear anywhere in the paper. When a reporter tracked down the lead author in 1999, he told her his data couldn’t support what people were doing with it. The statistic kept spreading anyway.

In this episode, Zoë and Kylee look at what the long-term weight loss research actually shows. That includes the Look AHEAD trial, a meta-analysis of 80 trials and more than 26,000 people, the National Weight Control Registry, and Kevin Hall’s famous Biggest Loser study. They also get into why hunger hormones stay shifted for a year after dieting, why diet rigidity predicts failure better than any specific diet does, how dropout bias makes the published numbers look better than reality, and where GLP-1 medications fit in. Kylee talks about what metabolic adaptation looks like in her clinical practice. Both hosts explain why “define diet, define failure, define percent” is the only correct response at a bar.

The bottom line: diets don’t fail 95% of the time. With a serious definition of success, the real failure rate is somewhere between two-thirds and 90%, and that’s with intensive professional support. The real number is still not encouraging. But a statistic you can’t source isn’t evidence. It’s a bumper sticker.

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Nearly a third of Americans say they're trying to avoid gluten. About 1% have celiac disease. That gap is worth billions of dollars. In this episode, Zoë and Kylee dig into who the gluten-free diet was actually designed for, how it became a wellness identity, and what the research says about the rest of us.

We start with the science: what gluten is, why no human fully digests it (and why that's fine), and what celiac disease does to the gut. It's a serious autoimmune condition, and about 70% of cases go undiagnosed. Then we trace the gluten-free diet from its unlikely origin in the Dutch famine of World War II to the bestseller shelf, where Wheat Belly and Grain Brain blamed wheat for everything from belly fat to Alzheimer's. Along the way we ask whether modern wheat is really different, whether non-celiac gluten sensitivity is real, and why the culprit is often FODMAPs, not gluten. We also look at the blinded studies showing how powerfully expectation shapes symptoms.

Plus: why gluten-free labels make food seem healthier than it is, what that does to people who actually need the label, whether gluten-digesting enzyme pills work, what happened when cyclists were blinded to their diets, and the question everyone asks. Why can you eat all the bread you want in Italy and feel fine?

Multi-level marketing was invented to sell vitamins. Not adjacent to vitamins, not eventually pivoted to vitamins: the first MLM in America was a 1945 alfalfa-pill company that got raided by the FDA within two years, and everything since (Amway, Herbalife, the friend from high school who wants you to try a shake) is running the same play. In this episode, Zoë and Kylee trace how diet culture and direct selling grew up as one machine: the Nutrilite origin story, why supplements are the perfect MLM product, Herbalife's unmarked nutrition clubs and the mystery of why the shake tastes better in the store than at home, the billionaire slap fight that ended in a $200 million FTC settlement, and what the independent numbers say about who actually makes money (almost no one). Plus: Betsy DeVos's grandfather, the Tupperware party as feminist history, and why "boss babe" is doing unpaid PR for a system built to move money out of women's pockets.

If you got pulled in, or watched someone you love get pulled in, the math was rigged before anyone signed up. That's the whole point.

Full transcript, references, and research at yourdietsuckspodcast.com.

Support Your Diet Sucks on Patreon for monthly bonus episodes, weekly nutrition question threads with Kylee, members-only recipes and posts, and the archive: patreon.com/YourDietSucks

This episode is supported by:

• rabbit: our title sponsor and the run apparel we actually wear. Use code SUMMERSNACKS10 for 10% off at runinrabbit.com
• Tailwind Nutrition: endurance fuel and hydration that won't wreck your gut. Use code YOURDIET20 for 20% off at tailwindnutrition.com
• Microcosm Coaching: evidence-based run coaching from humans, not algorithms. Book a free consultation at microcosm-coaching.com

Support us on Patreon!

Somewhere in the last few years, cortisol became the answer to everything. Tired? Cortisol. Puffy? Cortisol. Gained weight, lost sleep, can't stop scrolling? Cortisol. A hormone you would die without got recast as the thing wrecking your face, and a $4.8 billion supplement economy showed up to fix it. This episode asks how that happened, and whether any of it is new.

It isn't. Zoë traces the lineage: Hans Selye, the self-described father of stress, who built the modern idea of stress from rat experiments in the 1930s and then quietly took tobacco industry money for decades while his research was used in court to argue that stress, not cigarettes, was making people sick. Then the 1998 arrival of "adrenal fatigue," a diagnosis coined by a naturopath in a self-published book, dismissed by the Endocrine Society, and treated with ground-up cow adrenal glands that are still on Amazon today. Cortisol panic is adrenal fatigue with a real hormone bolted on.

Kylee handles the real hormone. What the HPA axis actually does, why the morning spike is a sign your system works, why a cortisone shot and "the stress hormone" are the same molecule, and what a proper cortisol test looks like versus a $500 saliva kit with poor day-to-day reliability. We take on cortisol face (the clinical version is Cushing's, and you'd know), cortisol belly (the mechanism is real at pathological levels and unsupported for a stressed person with a normal curve), and the cortisol cocktail (orange juice and salt, which is an electrolyte drink in a wine glass).

For athletes, the internet has it backwards. A hard workout can briefly push cortisol into Cushing's range, then it's gone in hours. Real overtraining blunts the stress response rather than flooding it, and under-fueling raises baseline cortisol because your body reads a chronic deficit as an ongoing threat. Skipping intensity to protect your hormones protects nothing.

If cortisol is where a structural problem gets relocated onto an individual body, the gummy can't fix the job, the rent, or the toddler. Sleep, carbohydrates, and recovery still can.

• rabbit: our title sponsor and the run apparel we actually wear. Use code SUMMERSNACKS10 for 10% off at runinrabbit.com
• goodr: $25 polarized sunglasses that don't bounce, don't slip, and don't cost a race entry. Use code YDS at goodr.com/YDS for $10 off.
• Tailwind Nutrition: endurance fuel and hydration that won't wreck your gut. Use code YOURDIET20 for 20% off at tailwindnutrition.com
• Microcosm Coaching: evidence-based run coaching from humans, not algorithms. Book a consultation at microcosm-coaching.com

Support the show at Patreon.com/yourdietsucks

"No days off" is a slogan, a t-shirt, and a diagnostic criterion, depending on who's reading it.

This week: exercise addiction. Whether it's real, whether "addiction" is even the right word, and why the whole concept was popularized by a psychiatrist who also thought clinical depression was a choice you could simply make differently.

We trace it from a 1970 sleep study that fell apart because the researcher couldn't find enough people willing to stop exercising for thirty days, to the 1976 book that told a generation being hooked on running was a personality upgrade, to the 1983 paper that could only make men's version legible by borrowing the vocabulary of anorexia.

Plus: what the prevalence research actually shows, why the brain-imaging literature fits in a three-ring binder, and four ways to tell dedication from compulsion that have nothing to do with your weekly mileage.

Sponsors

This episode is brought to you by rabbit, whose new women's collection is built for people who actually run in it. ⁠runinrabbit.com/collections/womens-new⁠, code SUMMERSNACKS10 for 10% off.

Tailwind Nutrition got us through this one. ⁠tailwindnutrition.com⁠, code YOURDIET20 for 20% off.

Microcosm Coaching works with athletes who want to train and fuel without the shame spiral. ⁠microcosm-coaching.com⁠

Links

Every episode and full transcripts: ⁠yourdietsuckspodcast.com/your-diet-sucks-podcast⁠

Bonus episodes, Kylee's weekly nutrition question thread, and a group chat that will never try to sell you a binder: ⁠patreon.com/YourDietSucks⁠

Support the show at Patreon.com/yourdietsucks

There is no plastic spoon in your brain (unless you put one there). There is no credit card in your diet. We regret to inform you that this does not mean everything is fine.

Both of those numbers came from real studies, and both got mangled somewhere between the paper and your feed. Kylee walks through what actually survives scrutiny, where the fertility conversation outruns its evidence, and why the BPA-free sticker on your Nalgene is not the reassurance you think it is.

Zoë traces the whole mess from exploding celluloid billiard balls to Life magazine throwing a party for disposability in 1955. We get into why humans are catastrophically bad at judging exactly this kind of risk, how much you should actually be thinking about it, and the one exposure source that matters more than anything in your kitchen drawer.

Nobody needs to panic about their hydration strategy. Maybe buy new spatulas. Definitely don't buy the $300 filter from the guy who could be regulating this instead.

Sponsors

This episode is brought to you by rabbit, whose new women's collection is built for people who actually run in it. runinrabbit.com/collections/womens-new, code SUMMERSNACKS10 for 10% off.

Tailwind Nutrition got us through this one. tailwindnutrition.com, code YOURDIET20 for 20% off.

Microcosm Coaching works with athletes who want to train and fuel without the shame spiral. microcosm-coaching.com

Links

Every episode and full transcripts: yourdietsuckspodcast.com/your-diet-sucks-podcast

Bonus episodes, Kylee's weekly nutrition question thread, and a group chat that will never try to sell you a binder: patreon.com/YourDietSucks

BPC-157. TB-500. MOTs-C. If those sound like droids from a Star Wars spinoff, congratulations on your healthy relationship with the internet. For everyone else: peptides are the injectable wellness trend that jumped from bodybuilding forums to med spas to your feed, promoted for healing, muscle, fat loss, and living forever. But what does the science say, and what are peptides, actually?

Some of them became legitimate blockbuster drugs: insulin is a peptide, and so are the GLP-1s. But the ones flooding your feed never went through human trials. They went from lab animal studies straight to "research chemical" websites, and from there to longevity clinics charging four figures for injections of compounds nobody has proven do anything in people.

This week, Zoë traces how we got from insulin to Instagram: the bodybuilding underground, the anti-aging clinics, and the influencer economy that turned unproven injectables into a billion-dollar category. Kylee breaks down what the research actually shows for the big-name peptides, why "thousands of patients swear by it" is not evidence, and what she tells athletes who ask whether BPC-157 will fix their tendons faster. Plus: what to know about anything sold in a vial labeled "for research purposes only."

rabbit: our title sponsor and the run apparel we actually wear. Use code SUMMERSNACKS10 for 10% off at runinrabbit.com

Tailwind Nutrition: endurance fuel and hydration that won't wreck your gut. Use code YOURDIET20 for 20% off at tailwindnutrition.com

Osmia: small-batch skincare made by a former ER doctor. Use code YDS20 for 20% off at osmiaskincare.com

Microcosm Coaching: evidence-based run coaching from humans, not algorithms. microcosm-coaching.com

Support us on Patreon!

Keto promised something no other diet could: cut the carbs, flip a metabolic switch, and burn fat without counting a single calorie. A magic loophole in human physiology. So does it actually work?

This week we trace keto from a deaf Victorian undertaker who accidentally invented the first diet book, to a 1920s epilepsy clinic that turned fasting into medicine, to the bankrupt Atkins empire, to the shirtless guys on TikTok insisting grains ruined their lives. Then we get into the science: what ketosis actually is, why the carb-insulin hypothesis doesn't survive a metabolic ward, what Kevin Hall's lockdown studies really found, and why you should treat "it worked for me" with a grain of ketogenic salt.

We also get specific about athletes: what fat adaptation can and can't do and who might genuinely benefit from a low-carb approach versus who's just going to get slower and crankier (Zoë, for sure).

• rabbit: 10% off with code SUMMERSNACKS10 at runinrabbit.com
• Tailwind Nutrition: 20% off with code YOURDIET20 at tailwindnutrition.com
• Osmia Skincare: 20% off with code YDS20 at osmiaskincare.com
• Microcosm Coaching: work with a real human coach at every level at microcosm-coaching.com