12 Nutrition Myths You Should Stop Believing (According to Science)
Renzy
May 21, 2026 · 9 min read
Quick answer
The most harmful myths: detox diets do not exist (your liver and kidneys already detox you), eating at night does not make you gain more weight, carbohydrates do not make you fat on their own, eggs do not spike your cholesterol, there are no fat-burning foods, a "slow metabolism" is almost always just less muscle and less movement, and no exercise burns localised fat. The real foundation is simple: calories, protein, minimally processed food, strength, sleep and consistency.
Nutrition is the perfect field for myths: everyone eats, almost no one has studied physiology, and the industry profits by selling complicated solutions to simple problems. The result is a sea of beliefs that sound logical but are false, costing you time, money and motivation. Let us debunk the 12 most widespread ones with what the evidence actually says.
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Before we start, one idea that saves a lot of time: if a nutrition recommendation sounds too specific, magical or restrictive ("this food burns fat", "do not mix X with Y"), it is almost certainly a myth. Nutrition that works is boringly simple.
And 7 more myths, briefly
6. "Eggs spike your cholesterol": false for most people; dietary cholesterol barely affects blood cholesterol.
7. "Crunches burn belly fat": spot reduction does not exist; fat decreases with an overall deficit.
8. "Gluten/lactose is bad for everyone": only for those with intolerance or coeliac disease; for everyone else, no.
9. "Light or diet products help you lose weight": marketing is not nutrition; check the table per 100 g, not the packet.
10. "Eating every 3 hours boosts metabolism": meal frequency does not change your total expenditure.
11. "Sweating a lot makes you lose weight": sweat is water you recover by drinking, not fat.
12. "Fruit makes you fat because of its sugar": whole fruit, with its fibre, is one of the best foods you can eat.
Renzy helps you with what actually matters: tracking your real calories and macros with a photo, no myths, no miracle products. Data, not marketing.
Scan your food with a photo. Calories, macros and micronutrients in 3 seconds.
Every time you doubt a recommendation, ask yourself: is it simple and boring, or magical and specific? Nutrition that works is the former. Leave the myths behind and focus on the basics, measured with Renzy.
Renzy calculates all of this for you
Scan your food with a photo. Calories, macros and micronutrients in 3 seconds.
1The essentials: (1) detox, eating at night, carbohydrates, fat-burners and slow metabolism are myths; (2) the real foundation is calories, protein, minimally processed food, strength, sleep and consistency; (3) if a recommendation sounds magical or very specific, be sceptical.
Nutritional information and health calculations in Renzy are for informational purposes only and are based on recognized scientific sources (USDA Food Database, ESPEN, WHO). They do not replace professional advice from a qualified doctor, nutritionist, or dietitian. Always consult a health professional before changing your diet or following medical recommendations.
