Most "nutrition wisdom" you've heard is wrong. Some of it was right 30 years ago and got disproven. Some was always marketing. Here are the 10 myths I correct most often in my clinic — with the actual science.
Myth 1: Carbs make you fat
The myth: Carbs spike insulin which stores fat. Cut them and you lose weight.
The truth: Calories make you fat. Carbs are 4 cal/g, same as protein. Eating more energy than you burn — from carbs, fat, or protein — leads to weight gain.
The science: Multiple meta-analyses (most recent: 2023, 2,500+ subjects) show no weight-loss advantage of low-carb over balanced diets when calories are matched. Low-carb works for some people because it spontaneously reduces calorie intake (protein and fat are filling). It's not magic; it's just lower calories.
What matters: total calories, protein adequacy, fibre intake. Carbs from rice, oats, lentils, fruit, sweet potato are all fine.
Myth 2: Fat is bad for you
The myth: Fat clogs arteries and makes you fat. Low-fat is healthy.
The truth: This is 1980s science that's been overturned. The low-fat era (1980–2000) coincided with the worst obesity surge in history because low-fat products replaced fat with sugar.
The science: The PREDIMED trial (7,000+ people, 5 years) showed Mediterranean diets high in olive oil and nuts reduce heart disease 30% vs. low-fat diets. Saturated fat from whole foods (eggs, full-fat yogurt) doesn't drive heart disease in current evidence.
Skip: trans fats, ultra-processed seed oils, deep-fried foods. Keep: olive oil, avocado, nuts, fish, whole eggs, full-fat dairy.
Myth 3: Eating after 8 PM causes weight gain
The myth: Late-night eating = weight gain because your metabolism slows.
The truth: Total daily calories matter, not the clock.
The science: Studies on late vs. early eaters with matched calories show no weight difference. There IS a small benefit to eating earlier (better insulin sensitivity, easier sleep), but a 9 PM dinner does not store as fat any differently than a 6 PM one.
What's true: late eaters often eat more total food (snacks after dinner add up), and heavy meals 2 hours before sleep disrupt sleep quality. Eat dinner before 9, ideally. But the clock isn't the problem — the total volume often is.
Myth 4: You need to detox to lose weight
The myth: Toxins build up. Cleanses, juices, and detox teas flush them out.
The truth: Your liver and kidneys are world-class detox organs that work 24/7 for free. No juice cleanse outperforms them.
The science: Zero clinical evidence that detox protocols remove "toxins" beyond normal liver/kidney function. The weight you lose on a juice cleanse is water and muscle, not fat. It comes back the second you eat normally.
What helps your detox systems: enough water, enough protein, enough fibre, less alcohol, more cruciferous vegetables (broccoli, cabbage). Boring, but real.
Myth 5: Skipping breakfast boosts weight loss
The myth: Skipping breakfast forces your body to burn fat.
The truth: Some people do well skipping breakfast. Others overeat the rest of the day. The breakfast question is individual.
The science: Breakfast eaters and skippers show similar weight outcomes when total calories match. What matters: are you genuinely not hungry until noon (skip is fine), or are you white-knuckling and binging at lunch (eat breakfast)?
If you skip breakfast and feel great, fine. If you skip and crash at 3 PM into the office cookies, eat a 30g-protein breakfast and watch your day stabilize.
Myth 6: All calories are equal
The myth: A calorie is a calorie. 200 cal of broccoli = 200 cal of biscuits.
The truth: Calories matter for weight, but the quality matters for hunger, hormones, and what your body builds with them.
The science: 200 cal of broccoli = 6g protein, 8g fibre, water, magnesium, full satiety. 200 cal of biscuits = 2g protein, 1g fibre, sugar spike, hungry in an hour. Same calories, very different downstream effects on appetite, blood sugar, and body composition.
For weight: calories matter. For everything else: food quality matters more.
Myth 7: Protein only matters for bodybuilders
The myth: You only need extra protein if you lift weights.
The truth: Everyone needs adequate protein. Especially women, especially over 40, especially anyone losing weight.
The science: Adults preserve muscle mass during weight loss only with adequate protein (1.4–1.6g/kg). Below that, you lose muscle along with fat — making your metabolism slower and your body composition worse. Older adults specifically need 1.5g/kg minimum to prevent sarcopenia.
Read the protein intake guide for the full math.
Myth 8: Supplements replace real food
The myth: Take a multivitamin and you've covered your bases.
The truth: Whole foods contain hundreds of compounds working together. Pills give isolated nutrients out of context.
The science: A multivitamin doesn't reduce mortality or chronic disease in healthy adults (multiple long-term cohort studies). Specific deficiencies (D, B12) require targeted supplementation. General "insurance" multivitamins are not a substitute for vegetables, protein, and whole grains.
When supplements help: confirmed deficiency, specific life stages (pregnancy, post-50), dietary restrictions (vegan B12). Otherwise, eat the food.
Myth 9: Organic food is always healthier
The myth: Organic = no chemicals = healthier.
The truth: Organic is better for the environment and lower in pesticide residue. The nutritional difference is small to zero.
The science: Multiple meta-analyses (Stanford 2012, others since) found no consistent nutritional advantage of organic over conventional produce. Organic does have lower pesticide residue, which matters for some foods (the "Dirty Dozen" — strawberries, spinach, etc.). For others (avocado, banana, onion), conventional is fine.
Eat more vegetables, organic or not. The bigger problem is people buying organic snacks and assuming healthy — organic biscuits are still biscuits.
Myth 10: You need to eat 6 small meals a day
The myth: Frequent small meals "stoke your metabolism."
The truth: Meal frequency doesn't significantly affect metabolic rate. Total food matters; timing of meals is a personal preference.
The science: Studies show no metabolic advantage to 6 meals vs. 3 meals when total calories match. Some people do better with 3 larger meals (better satiety, easier to track). Others prefer smaller meals. The "6 meals to boost metabolism" claim was based on the small thermic effect of food (~10% of calories) — but it doesn't matter how you split it.
What matters: a structure that keeps you satisfied and on-target with daily nutrients.
What actually works
Sustainable nutrition is boring on purpose:
- Eat enough protein (1.2–1.6 g/kg)
- Eat enough fibre (25g+ daily)
- Eat mostly whole foods (80% rule)
- Hydrate adequately (your body weight × 0.033 = litres)
- Sleep 7–9 hours
- Move daily
- Manage stress
- Get tested for the deficiencies that matter (D, B12, ferritin, lipids)
- Be consistent over months, not strict over days
- Adjust based on results, not trends
That's it. Everything else is noise.
Where to go from here
If you've been confused by conflicting nutrition advice for years, get science-backed nutrition advice — one consultation with me to map out what actually applies to your body. Or read all our articles for more myth-busting and practical guides. Ready to get started? Begin your health journey inside Greenofig.
