The Most Persistent Nutrition Myths, Examined

The 'carbs cause fat gain' idea often stems from a misreading of how insulin works. Yes, carbohydrates trigger insulin release — but insulin's job is to shuttle nutrients into cells for energy, not to automatically store them as fat. Whole food carbohydrate sources like legumes, oats, and vegetables also deliver fibre, vitamins, and minerals. Our guide on dietary fibre explains why fibre-rich carbs are especially valuable. What genuinely matters is the overall quality and quantity of what you eat, not carbohydrate as a category.

This myth largely emerged from low-fat dietary guidelines promoted in the 1980s and 1990s. In reality, fat provides nine calories per gram (versus four for carbs and protein), which means calorie density is worth being aware of — but fat itself is not the villain. Unsaturated fats found in foods like avocados, nuts, and oily fish are consistently linked to positive health markers in research. The broader dietary pattern matters far more than isolating one macronutrient.

'Detox' is one of the most misused words in wellness marketing. The human body has sophisticated, built-in detoxification systems — primarily the liver and kidneys — that operate constantly. When researchers examine juice cleanses or detox supplements in well-controlled studies, they find no meaningful evidence of improved toxin removal compared to ordinary eating. Some cleanses are also very low in protein, which can leave people fatigued and hungry without producing lasting benefit. If digestive health is a genuine concern, speaking with a healthcare professional is the most productive next step.

The idea that skipping meals 'trains' your body to burn more efficiently isn't supported by the bulk of evidence. What research does suggest is that very large calorie deficits — often created by skipping meals — can trigger adaptive thermogenesis, a process where the body conserves energy by slowing metabolic rate. Intermittent fasting, which is a structured approach to meal timing, is a different concept with its own mixed evidence base. If you're curious about that specifically, our balanced look at intermittent fasting trade-offs is worth reading before you try it.

Sports nutrition research has evolved considerably on this point. While protein does support muscle repair after exercise, studies suggest that for most recreational exercisers, what matters most is total daily protein intake and overall diet quality — not whether you consumed a shake within 30 minutes of finishing a workout. The urgency framing around post-workout nutrition is more relevant to elite athletes training multiple times a day. For everyday active living, consistency across the whole diet is the more meaningful variable. See our Fitness & Movement hub for more evidence-based exercise guidance.