Twenty claims people repeat about food, weight and health, each with a verdict and what the evidence shows. The verdicts differ on purpose: eleven read mostly false, four read partly true, two rest on mixed evidence, and three are reductive, risky or badly framed. A library where every answer read false would teach the wrong reflex.
Macro Fears
“Carbs make you fat.”
No, calorie excess does. Distinguish simple from complex carbohydrate, and pair carbohydrate with protein. The plate matters a great deal more than the category does.
“Fat is bad for you, and fat-free is healthy.”
No. Hormone production and the absorption of fat-soluble vitamins both need dietary fat. Quality matters more than amount here, which is why omega-3 and trans fat do not belong in the same sentence.
“Protein is bad for your kidneys.”
No. In healthy kidneys, higher protein intake is safe. The myth comes from a misreading of the protein-restriction literature in chronic kidney disease, where the restriction is a treatment for existing damage rather than prevention of it.
“Eating after 8pm makes you gain weight.”
No. Total calories matter rather than the clock. A late meal can spike glucose when it is low in protein, but the timing on its own is not the cause.
“You need to eat every two to three hours to keep your metabolism going.”
No. Meal frequency does not move metabolic rate enough to matter for body composition. It can help blood sugar in specific clinical contexts, and only in those.
The Glp-1 Era
“GLP-1 ruins your relationship with food.”
The drug can blunt eating cues, which brings both benefits and risks. The relationship gets better or worse depending on what coaching wraps around it.
“Once you stop GLP-1 you regain everything.”
Without skill-building during the drug, regain is likely; with skill-building, the regain curve flattens. The drug is not the problem. The off-ramp is.
“GLP-1 only works because it makes you eat less.”
The mechanism is gut-brain, and there are insulin-sensitivity and inflammatory effects that run independently of the reduction in intake.
“You don’t need to track or learn anything, because the drug does the work.”
The drug suppresses intake; it does not teach the patient anything. The patient who learns nothing during the drug year is the patient who regains in year two.
“GLP-1 causes muscle loss, so you should avoid it.”
GLP-1 plus a caloric deficit plus low protein plus no resistance training does cost lean mass. With adequate protein and training, lean mass losses look similar to weight loss without the drug.
Supplements
“Natural means safe, and herbal means harmless.”
No. Many herbs are bioactive at supplement doses: St. John’s wort interacts with SSRIs, high-dose vitamin A can be teratogenic, and kava is hepatotoxic. Natural is a marketing word rather than a safety claim.
“More vitamin D is better.”
No. The optimal serum range sits around 30 to 60 ng/mL for most adults, and above 100 ng/mL there is a hypercalcemia risk. Mega-dosing is not benign.
“Multivitamins are pointless.”
For somebody eating a varied diet, the marginal benefit is small. For somebody on GLP-1 with restricted intake, post-bariatric, vegan, or elderly, a basic multivitamin is reasonable. The category is not useless; the blanket claim is.
“Magnesium, collagen and fiber gummies fix everything.”
Each has a narrow real benefit, meaning magnesium for sleep and muscle, collagen for skin elasticity on weak evidence, and fiber gummies for a fiber gap. The fixes-everything framing is influencer marketing rather than science.
“Antioxidant supplements prevent cancer and aging.”
Results run mixed to negative, and high-dose vitamin E and beta-carotene have shown harm in some trials. Food-form antioxidants are the safer bet.
Lifestyle & Culture
“Skipping breakfast slows your metabolism.”
No. Breakfast timing does not move metabolic rate. Some people do well skipping it and others do poorly, which makes this individual variation rather than a rule.
“Detoxes and cleanses clean out your system.”
No. Your liver and kidneys do that. Detox products either contain laxatives, which produce water loss rather than toxin removal, or they are placebos.
“You can’t be healthy and eat rice, plantain, pasta or tortillas.”
No. Portion and pairing are what matter. Cultural staples were never the problem; processing and portion drift are.
“Organic and clean eating is the only safe way.”
No. The marginal health benefit of organic over conventional is small for most people, and the marketing has outpaced the evidence. Eat more vegetables.
“Calories in and calories out is everything, or it is nothing.”
Both extremes are wrong. Energy balance is the dominant determinant of body weight over time, while hormonal, behavioral and environmental factors modify how much a person eats and burns. Both layers matter.
Longer entries, with the origin of each myth and the full source list, are being written and will appear here one at a time. Want these as printable cards? The 20-Myth Flashcard Deck. Want to test a claim that is not on this list? Run it through the fact check.
Educational. Not medical advice, not a diagnosis and not an individualized nutrition plan. © 2026 Fact Over Myth LLC.
