In the world of nutrition, misinformation spreads quickly, leading many people to adopt ineffective or even harmful dietary habits. With countless fad diets, weight-loss trends, and contradicting advice, it can be difficult to separate fact from fiction. Many common diet myths persist despite being debunked by scientific research, misleading individuals who are trying to improve their health and fitness.
This article will examine five of the most widespread diet myths and provide evidence-based explanations to set the record straight. By understanding the truth behind these misconceptions, you can make more informed decisions about your diet and overall well-being.
Myth 1: Carbs Make You Fat
Many people believe that carbohydrates are the primary cause of weight gain. However, scientific research does not support this claim. Carbohydrates themselves do not inherently cause fat gain; rather, it is an excess of calories, regardless of the macronutrient source, that leads to weight gain. A study by Hall et al. (2015) found that when calorie intake was controlled, low-fat and low-carb diets led to similar fat loss results, indicating that total energy intake is more important than macronutrient composition.
The misconception arises because refined carbohydrates, such as white bread and sugary snacks, can cause spikes in insulin levels, which may increase hunger and lead to overeating (Ludwig et al., 2018). However, complex carbohydrates found in whole grains, vegetables, and legumes are highly beneficial for overall health and provide sustained energy.
Myth 2: Eating Fat Makes You Fat
For decades, dietary fat was demonised as the leading cause of obesity. However, research has shown that fat is an essential macronutrient necessary for hormone production, brain function, and nutrient absorption.
A study by Tobias et al. (2015) found that low-fat diets were not more effective for long-term weight loss than higher-fat diets. In fact, high-fat, low-carbohydrate diets, such as the ketogenic diet, have been shown to promote weight loss and improve metabolic health (Feinman et al., 2015).
The key is to differentiate between healthy fats—such as those found in avocados, nuts, seeds, and olive oil—and unhealthy trans fats found in processed foods. The latter have been linked to an increased risk of cardiovascular disease (Mozaffarian et al., 2006).
Myth 3: Eating Late at Night Causes Weight Gain
A widespread belief is that consuming food late at night leads to fat accumulation. While some studies have suggested that eating closer to bedtime may be linked to weight gain, the primary factor remains overall daily calorie intake. A study by De Castro (2004) found that late eaters tend to consume more calories throughout the day, which may explain the association with weight gain.
Another study by Sofer et al. (2011) found that meal timing had little impact on weight loss when total calorie intake was controlled. The body does not automatically store calories as fat based on the time of day; instead, weight gain occurs when calorie intake exceeds expenditure. However, late-night eating can disrupt sleep quality, which may indirectly impact metabolism and hunger hormones (Crispim et al., 2011).
Myth 4: Detox Diets and Cleanses Remove Toxins from the Body
Detox diets and juice cleanses are often marketed as essential for eliminating toxins and promoting weight loss. However, there is no scientific evidence supporting the idea that these diets enhance the body’s natural detoxification processes. The liver and kidneys are responsible for detoxification, effectively removing waste and toxins from the body without the need for special diets (Smith & Vale, 2003).
A review by Klein and Kiat (2015) found that detox diets lack scientific credibility and can sometimes be harmful due to nutrient deficiencies. While some detox diets may lead to short-term weight loss, this is typically due to water loss rather than fat loss. Instead of relying on detox programs, focusing on a nutrient-dense diet rich in fibre, lean proteins, and healthy fats is the best approach for supporting overall health.
Myth 5: You Need to Eat Small, Frequent Meals to Boost Metabolism
The idea that eating multiple small meals throughout the day boosts metabolism and aids weight loss is a common misconception. While digestion does cause a temporary increase in metabolic rate (the thermic effect of food), the overall impact on total daily energy expenditure is minimal.
A study by Schoenfeld et al. (2015) found no significant difference in fat loss between individuals consuming multiple small meals versus fewer larger meals when total calorie intake was the same.
Another study by Cameron et al. (2010) found that intermittent fasting, which involves eating fewer meals per day, can be just as effective for weight loss and metabolic health. Rather than focusing on meal frequency, prioritising total daily caloric intake and nutrient-dense foods is more important for body composition and overall health.
Key Takeaways
| Myth | Truth |
|---|---|
| Carbs make you fat | Weight gain occurs due to excess calorie intake, not carbohydrates themselves. Complex carbs are beneficial for health. |
| Eating fat makes you fat | Healthy fats are essential for health. Trans fats should be avoided, but fats do not inherently cause weight gain. |
| Eating late at night causes weight gain | Weight gain is determined by overall calorie intake, not meal timing. Late-night eating may affect sleep quality. |
| Detox diets remove toxins | The body naturally detoxifies through the liver and kidneys. Detox diets lack scientific evidence. |
| Small, frequent meals boost metabolism | Meal frequency has little impact on metabolism. Total calorie intake and nutrient quality matter more. |
Bibliography
- Cameron, J. D., Cyr, M. J. & Doucet, E. (2010) ‘Increased meal frequency does not promote greater weight loss in subjects who were prescribed an 8-week equi-energetic energy-restricted diet.’ British Journal of Nutrition, 103(8), pp. 1098-1101.
- Crispim, C. A., Zimberg, I. Z., dos Reis, B. G., Diniz, R. M., Tufik, S. & de Mello, M. T. (2011) ‘Relationship between food intake and sleep pattern in healthy individuals.’ Journal of Clinical Sleep Medicine, 7(6), pp. 659-664.
- De Castro, J. M. (2004) ‘The time of day of food intake influences overall intake in humans.’ Journal of Nutrition, 134(1), pp. 104-111.
- Feinman, R. D. et al. (2015) ‘Dietary carbohydrate restriction as the first approach in diabetes management: critical review and evidence base.’ Nutrition, 31(1), pp. 1-13.
- Hall, K. D. et al. (2015) ‘Calorie for calorie, dietary fat restriction results in more body fat loss than carbohydrate restriction in people with obesity.’ Cell Metabolism, 22(3), pp. 427-436.
- Klein, A. V. & Kiat, H. (2015) ‘Detox diets for toxin elimination and weight management: a critical review of the evidence.’ Journal of Human Nutrition and Dietetics, 28(6), pp. 675-686.
- Ludwig, D. S., Willett, W. C. & Volek, J. S. (2018) ‘Dietary carbohydrates: role of quality and quantity in chronic disease.’ British Medical Journal, 361, pp. k2340.
- Mozaffarian, D. et al. (2006) ‘Trans fatty acids and cardiovascular disease.’ New England Journal of Medicine, 354(15), pp. 1601-1613.
- Schoenfeld, B. J., Aragon, A. A. & Krieger, J. W. (2015) ‘Effects of meal frequency on weight loss and body composition: a meta-analysis.’ Journal of the International Society of Sports Nutrition, 12(1), pp. 39.
- Smith, C. M. & Vale, J. A. (2003) ‘Toxicology of vitamins and trace elements.’ British Journal of Clinical Pharmacology, 55(6), pp. 589-595.
- Sofer, S. et al. (2011) ‘Greater weight loss and hormonal changes after 6 months diet with carbohydrates eaten mostly at dinner.’ Obesity, 19(10), pp. 2006-2014.
- Tobias, D. K. et al. (2015) ‘Effect of low-fat diet interventions versus other diet interventions on long-term weight change in adults: a systematic review and meta-analysis.’ The Lancet Diabetes & Endocrinology, 3(12), pp. 968-979.
