I’m tired of watching people scare themselves away from keto with garbage information - so let’s separate keto myths and facts once and for all.
Every week someone tells me they’re worried keto will destroy their kidneys, or that it’s “just another fad,” or that they’ll lose all their muscle and end up weak and miserable. And every week I have to explain that no, the internet lied to you. Again.
The misinformation out there is genuinely frustrating because it keeps people from trying something that could actually help them. So let’s clear up the biggest keto myths and facts - with actual science, not fear-mongering blog posts written by people who’ve never even tried keto.
(New to keto and want the basics first? Check out our complete beginner’s guide before diving into myth-busting.)
Myth #1: “Keto is Just Another Fad Diet”
Myth: Keto is a temporary diet trend. Fact: The ketogenic diet has been used medically since the 1920s to treat epilepsy and is backed by over 2,000 peer-reviewed studies examining its effects on weight loss, diabetes, neurological health, and metabolic function. While recent marketing has increased its popularity, the underlying science is well-established and robust.
This one makes me roll my eyes so hard.
People see keto products everywhere - “keto bread,” “keto cookies,” all the Instagram ads - and assume it’s just the latest diet trend that’ll be gone in two years. I get why it looks that way. But the marketing doesn’t erase a century of medical science.
Here’s what actually matters: The ketogenic diet was developed in the 1920s to treat epilepsy in children. Not to sell protein bars. Not to make money on diet books. To stop seizures. And it worked so well that hospitals still use it today for that exact purpose.
This isn’t some Instagram influencer’s latest cash grab. It’s one of the most researched dietary approaches in medical literature.
The actual timeline:
- 1920s: Created for epilepsy treatment at Johns Hopkins Hospital
- 1970s: Scientists started studying the metabolic effects
- 2000s: Research exploded on weight loss and diabetes applications
- 2010s: Neurological research expanded to Alzheimer’s, Parkinson’s
- Today: Over 2,000 peer-reviewed studies on ketogenic diets
Yeah, the recent popularity created a marketing circus. But dismissing keto as a “fad” because of marketing is like dismissing antibiotics because pharmaceutical companies advertise them. The underlying science is robust and well-established.
Myth #2: “Keto Will Damage Your Kidneys”
This myth pisses me off because it scares people unnecessarily.
I’ve watched people with metabolic syndrome - who could genuinely benefit from keto - avoid it entirely because someone on the internet told them they’d wreck their kidneys. It’s not true. And it comes from confusing two completely different things.
Here’s the reality: No scientific evidence shows that ketogenic diets damage healthy kidneys. None. This myth confuses ketosis (a normal metabolic state) with ketoacidosis (a life-threatening diabetic emergency). They’re not even close to the same thing.
The difference that matters:
- Ketosis: Blood ketones 0.5-3.0 mmol/L (normal and safe - this is keto)
- Ketoacidosis: Blood ketones 10+ mmol/L (medical emergency - this is NOT keto)
You literally cannot reach ketoacidosis levels through diet alone if you have a functioning pancreas. It’s a complication of uncontrolled Type 1 diabetes, not something that happens from eating bacon and eggs.
What research actually shows:
- Zero kidney damage in healthy people eating keto
- May actually improve kidney function in some cases
- Reduces inflammation markers
- Improves blood pressure (which reduces kidney stress)
Important caveat: If you already have kidney disease, talk to your doctor before starting any new diet, including keto. That’s just common sense medical advice, not evidence that keto damages healthy kidneys.
Myth #3: “You Can’t Exercise on Keto”
Yeah, Week 1 on keto is going to suck for your workouts. I’m not going to sugarcoat it.
During that first week or two, your body’s still figuring out how to burn fat efficiently, and your performance will probably tank. I remember trying to do my normal workout routine in Week 1 and feeling like I was moving through concrete. It was demoralizing. (This is related to keto flu symptoms that most people experience early on.)
But here’s what nobody tells you when they’re fear-mongering about keto and exercise: it’s temporary.
Once you’re fat-adapted (usually 3-6 weeks in), most people experience equal or even better performance, especially for endurance stuff. Your body just needs time to learn a new fuel system.
The honest timeline:
- Week 1-2: Your workouts will feel terrible. This is normal. Your body’s confused.
- Week 3-6: Performance comes back to baseline. You start feeling human again.
- Month 2+: Many people experience improved endurance and more stable energy.
What the research actually shows:
- Better fat oxidation during exercise (you become a fat-burning machine)
- Stable energy without needing to carb-load
- Faster recovery between sessions
- Less inflammation after workouts
Real examples: Ultra-marathoners are using keto for endurance events. Professional athletes maintain it year-round. Plenty of strength athletes are successful on ketogenic diets. These aren’t weekend warriors experimenting - these are serious athletes who need their bodies to perform.
If you’re an athlete considering keto, give yourself that full 6-week adaptation period before deciding it doesn’t work. Don’t bail after Week 1 when everything feels hard.
Myth #4: “Keto Raises Cholesterol and Causes Heart Disease”
Okay, this one’s more complicated than the others, so stay with me.
The relationship between cholesterol and heart disease is way more nuanced than “cholesterol high = heart attack imminent.” The science has evolved a lot in the past decade, but a lot of doctors are still operating on outdated information from the 1980s.
Here’s what actually happens for most people on keto:
What usually improves:
- HDL (good) cholesterol goes up
- Triglycerides drop significantly (this is huge)
- Blood pressure often decreases
- Inflammation markers improve
- Blood sugar control gets way better
- Weight loss reduces overall cardiovascular risk
For most people, their cardiovascular risk profile gets better on keto, not worse.
The LDL question (the complicated part): Some people see LDL increase. Others see it decrease. Individual responses vary a lot. But even when LDL goes up, the particle size often improves - you get larger, fluffier particles that are less likely to cause problems than small, dense particles.
Total cardiovascular risk typically decreases even if LDL ticks up, but this is where individual monitoring becomes important.
When you should be more cautious:
- Family history of cardiovascular disease
- Existing heart conditions
- Genetic predisposition to high cholesterol (like familial hypercholesterolemia)
If any of these apply to you, work with a doctor who’s actually knowledgeable about keto (not one who just tells you to eat more whole grains without looking at your actual markers). Monitor your lipid panels. Make informed decisions based on your specific situation.
Myth #5: “Keto Causes Muscle Loss”
This myth drives me crazy because it’s based on outdated assumptions about how the body works.
The thinking goes: “You need carbs for muscle, no carbs means you lose muscle.” Sounds logical. Also wrong.
Properly implemented keto preserves muscle mass better than many other diet approaches, especially when you combine it with resistance training. I’ve maintained and even gained muscle on keto. So have countless athletes and bodybuilders.
Why keto preserves muscle:
- Adequate protein intake maintains muscle (obviously)
- Ketones themselves have muscle-sparing effects
- Growth hormone levels often increase on keto
- Reduced inflammation helps recovery
What research actually shows:
- Muscle retention similar to higher-carb diets
- When combined with resistance training, muscle gain is absolutely possible
- Many bodybuilders successfully use ketogenic diets for both cutting and maintaining
Keys to keeping your muscle:
- Eat enough protein (0.8-1.2g per kg body weight minimum - learn to calculate your personal macros)
- Actually lift weights - resistance training is non-negotiable
- Don’t severely restrict calories (crashing your calories will cost you muscle on any diet)
- Allow that adaptation period before judging your strength gains
The people who lose muscle on keto are usually making one of two mistakes: they’re not eating enough protein, or they’re severely restricting calories. Fix those problems and muscle loss isn’t an issue.
Myth #6: “Keto is Dangerous for Women”
This one needs nuance, not blanket statements.
Keto can absolutely be beneficial for women - I’ve seen it dramatically improve PCOS symptoms, stabilize energy, and help with hormonal balance. But some women do need modifications, especially around menstruation, pregnancy, and menopause.
What actually happens for women:
Menstrual cycles: Some women experience changes initially - cycles might get irregular or heavier or lighter. This usually normalizes within 2-3 months as your body adjusts. For women with PCOS, keto often improves symptoms significantly.
Pregnancy and breastfeeding: Strict keto isn’t recommended during pregnancy - your baby needs adequate glucose for development. Modified low-carb approaches can work, but talk to your OB. Breastfeeding mothers need adequate calories and often do better with a bit more carbs (30-50g instead of strict 20g).
Thyroid function: If you have existing thyroid issues, monitor them closely. Some women need slightly higher carbs for optimal thyroid function. Stress management becomes even more important.
Benefits I’ve seen for women:
- Major PCOS symptom improvements (this one’s huge)
- Better hormonal balance in many cases
- Reduced inflammation and pain
- More stable energy and mood
The key is listening to your body. If your cycle goes wonky and stays wonky for months, or your energy crashes and doesn’t recover, you might need more carbs. That’s not keto “failing” - it’s your body giving you information. Adjust accordingly.
Myth #7: “You Need Expensive Supplements and Products”
Oh man, the keto product industry is out of control.
Walk into any supplement store and there’s an entire wall of “keto” products - exogenous ketones, MCT oil powders, keto meal replacements, specialty testing devices - all marketed as “essential” for keto success. Spoiler: most of it is complete bullshit.
Keto works perfectly well with whole foods and basic electrolyte support. That’s it. Everything else is either convenience (which is fine if you want to pay for it) or straight-up marketing.
What you actually need:
- Quality food sources (meat, fish, eggs, vegetables, healthy fats - understand clean vs dirty keto)
- Adequate sodium, potassium, magnesium (this is actually important)
- Maybe a basic multivitamin if your diet isn’t varied
What’s sometimes helpful but not required:
- MCT oil if you want easier ketosis or quick energy
- Magnesium supplement for sleep and cramps
- Electrolyte powder for convenience (but you can just salt your food)
What’s marketing hype:
- Exogenous ketones (not necessary for 99% of people)
- Anything labeled “keto” that’s just processed junk in new packaging
- $40 bags of “keto coffee” when butter and coffee cost $5
- Fancy ketone testing devices beyond basic pee strips (and even those are optional)
I started keto with real food, table salt, and magnesium pills from the drugstore. Spent maybe $5 on “keto-specific” products. Lost weight, felt great, saved a fortune. Don’t let anyone convince you that keto requires a second mortgage.
Myth #8: “Keto is Too Restrictive to Maintain”
Here’s the thing nobody tells you about keto: it feels less restrictive than regular dieting.
I know that sounds counterintuitive. You’re cutting out entire food groups. But hunger and cravings decrease so significantly that most people find it easier than calorie-counting diets where you’re constantly fighting your appetite.
Why keto feels less restrictive:
- Appetite suppression - ketones literally reduce your hunger signals
- Stable blood sugar - no more 3pm crashes and desperate snack hunts
- Fat keeps you full - you’re genuinely satisfied with less food
- Mental clarity - better decision-making around food when your blood sugar isn’t yo-yoing
I used to think about food constantly on other diets. On keto? I sometimes forget to eat lunch because I’m not hungry. That’s not willpower - it’s biology.
And it’s flexible:
- Cyclical keto (carb cycling around workouts or weekends)
- Targeted keto (carbs around training)
- Liberal keto (30-50g carbs instead of strict 20g)
- Intuitive keto (focus on principles, stop obsessive tracking)
You don’t have to do strict 20g keto forever. Many people find their sweet spot at 30-40g carbs where they maintain the benefits without feeling restricted. Others cycle in and out. Some use it as a tool for specific goals, then transition to maintenance.
Myth #9: “Keto Causes Hair Loss”
Okay, real talk: some people do experience temporary hair thinning on keto. But it’s not what you think.
Any significant dietary change or rapid weight loss can temporarily mess with your hair growth cycle. This happens with ANY diet where you lose weight quickly or change your eating dramatically. It’s not specific to keto.
What’s actually happening:
- Rapid weight loss stresses your body (any diet)
- Caloric restriction can trigger telogen effluvium (fancy term for temporary shedding)
- Stress of dietary change affects hormones
- Nutrient deficiencies if you’re not eating enough variety
- Hormonal adjustments during adaptation
How to prevent it:
- Don’t crash diet - eat adequate calories
- Make sure you’re getting enough protein
- Take a good multivitamin with biotin
- Manage your stress levels (easier said than done, I know)
- Be patient - hair growth cycles take 3-6 months to show changes
If you do experience some shedding, it usually resolves on its own within a few months as your body adjusts. I had some thinning around month 2-3, freaked out, almost quit keto. Glad I didn’t - it grew back fuller than before.
If hair loss continues beyond 6 months or seems excessive, get your thyroid and nutrient levels checked. That’s not normal and might indicate an underlying issue.
Myth #10: “You’ll Gain All the Weight Back”
This myth applies to every diet, not just keto. And it’s based on people’s behavior, not the diet itself.
Yeah, if you lose 50 pounds on keto, then immediately go back to eating exactly how you ate before, you’ll gain the weight back. That’s not a keto problem. That’s a “you returned to the eating habits that made you gain weight in the first place” problem.
But here’s what’s different about keto: it teaches you sustainable habits that many people naturally maintain long-term, even if they’re not doing strict keto anymore.
Why people maintain success after keto:
- Appetite regulation often stays improved even with moderate carbs
- Insulin sensitivity typically remains better
- Food relationships change - you learn to eat for fuel, not emotions
- Energy levels stay stable with better food choices
- Health improvements motivate you to keep most of the changes
Transition strategies that work:
- Gradually reintroduce carbs (start with 50g, then 75g, find your maintenance point)
- Keep the low-carb principles even if you’re not strict keto
- Continue focusing on whole foods instead of processed crap
- Monitor your health markers and how you feel
- Stay flexible without completely abandoning what you’ve learned
I know people who’ve maintained their weight loss for years after transitioning off strict keto. They eat around 75-100g carbs now, focus on whole foods, and maintain all the benefits. That’s sustainable.
How to Evaluate Keto Information
Not all keto advice is created equal. Here’s how to sort the good from the garbage:
Red flags that should make you skeptical:
- “Lose 30 pounds in 30 days!” (too good to be true = probably is)
- Promoting expensive products as “required” for success
- Ignoring individual variation (everyone’s different)
- Cherry-picking studies that support their point
- Extreme positions (“keto cures everything!” or “keto destroys your health!”)
Reliable sources:
- Peer-reviewed research (actual studies, not blog posts citing studies)
- Medical professionals who actually work with keto patients
- Long-term practitioners sharing honest experiences (the good AND the bad)
- Organizations without obvious financial conflicts of interest
When someone’s selling you something, their advice is suspect. When someone’s sharing what actually worked (or didn’t work) for them without trying to sell you a course or supplement, that’s usually more trustworthy.
The Bottom Line
Keto isn’t magic, and it’s not dangerous. It’s a tool.
Like any significant dietary change, it has benefits and potential drawbacks that vary by individual. Some people thrive on it. Others do better with moderate carbs. Both outcomes are fine.
What matters is:
- Understanding the actual science instead of internet fear-mongering
- Monitoring your individual response with real health markers
- Working with healthcare providers if you have medical conditions
- Focusing on whole foods instead of processed “keto” products
- Being patient with the adaptation process before deciding it doesn’t work
Don’t let myths and misinformation scare you away from trying something that could genuinely help you. But also don’t fall for the hype that keto is the answer to everything.
Make decisions based on science, your personal experience, and professional guidance - not random internet strangers with something to sell.
Ready to start? Our meal planning guide helps you turn knowledge into action with practical weekly strategies.
Want to learn more about the science behind keto? Download our Evidence-Based Keto Resource Guide with links to key research studies and reliable information sources.