Nutritional Myths vs Facts: Sorting Science from Fiction

By Carolyn Matthews, Food & Wellbeing Editor

In the world of nutrition, misinformation spreads like wildfire. From social media influencers pushing unscientific detox teas to well-meaning family members insisting that carbs are the devil, it can be hard to separate nutritional facts from fiction. In reality, many of the diet rules we think we know are either outdated, oversimplified, or outright false. So, let’s break down some of the most common nutritional myths and uncover what science actually says.

Myth 1: Carbs Make You Fat 

Fact: Carbohydrates are not inherently fattening. 

Carbs have been demonised for decades, largely due to the rise of low-carb diets like Atkins and keto. But here’s the reality: carbohydrates are the body’s primary source of energy. The problem isn't the carbs themselves as much as it is the overconsumption of refined and highly processed carbs, such as white bread, sugary cereals, and pastries. All of these cause spikes in blood sugar and can contribute to weight gain over time. However, whole-food sources of carbohydrates, like oats, brown rice, and sweet potatoes, are packed with fibre, vitamins, and minerals that support overall health. 

In fact, studies have shown that low-carb diets can help with short-term weight loss, but long-term sustainability and health outcomes tend to be better with balanced diets that include complex carbs. So, unless you're following a specific medical diet, there’s no need to fear carbs - just choose the right ones. 

Myth 2: Eating Late at Night Causes Weight Gain 

Fact: It’s not the timing - it’s the total calorie intake that matters. 

This myth likely stems from the belief that metabolism slows down at night, causing food to be stored as fat rather than burned for energy. However, metabolism functions continuously, even while we sleep. What actually matters is the total number of calories consumed versus the number burned throughout the day. 

That said, people who eat late at night often snack on high-calorie, nutrient-poor foods like crisps, biscuits, or ice cream, which can contribute to weight gain. But if your overall calorie intake is balanced, eating dinner at 9pm won’t inherently make you gain weight. 

Myth 3: You Need to Detox Your Body with Juices and Teas 

Fact: Your liver and kidneys already detox your body. 

Detox teas, juice cleanses, and expensive supplements claim to rid your body of toxins, but the truth is, your body has its own detoxification system: the liver, kidneys, and even the skin all work together to eliminate waste. Unless you have a medical condition affecting these organs, they do a perfectly fine job without the need for overpriced juices. 

Many detox products rely on laxatives, leading to temporary weight loss due to water loss rather than actual fat reduction. Instead of wasting money on detox fads, focus on eating a diet rich in whole foods, staying hydrated, and supporting your body's natural detoxification processes through a balanced diet.

Myth 4: High-Protein Diets Damage Your Kidneys 

Fact: In healthy individuals, high-protein diets do not harm kidney function. 

Protein has gained popularity due to its role in muscle building, satiety, and metabolic health. However, a long-standing myth suggests that high-protein diets can harm kidney function. This concern mainly applies to individuals with pre-existing kidney disease, where excessive protein intake can exacerbate existing problems. But for healthy individuals, research shows that high-protein diets do not negatively impact kidney function. 

That being said, balance is key. Overloading on protein at the expense of other macronutrients can lead to nutrient imbalances. But if you’re worried about your post-gym protein shake ruining your kidneys, you can relax - science says you’re fine.

Myth 5: Fresh Produce is Always Better Than Frozen 

Fact: Frozen fruits and vegetables can be just as nutritious - sometimes even more so. 

Many people assume that fresh produce is superior to frozen, but in reality, frozen fruits and vegetables are often picked at peak ripeness and flash-frozen, preserving their nutrients. On the other hand, fresh produce may lose some of its nutritional value during transport and storage. 

This doesn’t mean fresh produce is bad - far from it. But frozen options can be a convenient and affordable alternative that still packs a nutritional punch, especially when fresh options are out of season. 

Myth 6: Fat is Bad for You 

Fact: Healthy fats are essential for overall health. 

The low-fat craze of the 1990s did more harm than good, leading people to fear all dietary fats. However, we now know that fats are essential for brain function, hormone production, and overall health. The key is choosing the right types of fat. 

Unsaturated fats, found in avocados, nuts, seeds, and olive oil, offer numerous health benefits, including reduced inflammation and improved heart health. Meanwhile, trans fats - found in many processed foods - are genuinely harmful and should be avoided. Saturated fats, found in dairy and red meat, are still debated in the scientific community, but moderate consumption is generally considered fine within a balanced diet. 

Myth 7: You Need to Drink 8 Glasses of Water a Day 

Fact: Hydration needs vary between individuals.

The idea that everyone must drink exactly eight glasses of water daily is misleading. Hydration needs depend on factors like body size, activity level, climate, and diet. Foods with high water content, such as fruits and vegetables, also contribute to hydration. 

A better approach? Listen to your body. Thirst is a good indicator of when you need more fluids. A simple way to check hydration is by looking at urine colour: pale yellow indicates good hydration, while dark yellow suggests you may need more water.

Myth 8: Microwaving Food Destroys Nutrients 

Fact: Microwaving is actually one of the best cooking methods for nutrient retention. 

Some people worry that microwaving food destroys its nutrients, but research suggests that microwaving often preserves more nutrients than boiling or frying. Because microwaves cook food quickly and with minimal water, they help retain water-soluble vitamins like vitamin C and B, which can be lost through other cooking methods.

Of course, not all microwave meals are created equal—processed, pre-packaged microwave meals can be high in sodium and preservatives. But using a microwave to reheat or cook whole foods is completely safe and often nutritionally efficient.

Myth 9: Gluten-Free Diets Are Healthier for Everyone 

Fact: Unless you have coeliac disease or gluten sensitivity, there’s no need to avoid gluten. 

Gluten-free diets have become trendy, but for most people, they’re unnecessary. Gluten is a protein found in wheat, barley, and rye, and unless you have coeliac disease or a diagnosed gluten sensitivity, there is no scientific evidence that avoiding gluten offers health benefits. Many gluten-free products are highly processed and can lack essential nutrients like fibre, iron, and B vitamins. Instead of cutting out gluten unnecessarily, focus on consuming a diet rich in whole, unprocessed foods.

The Bottom Line 

Nutrition is complex, and the internet is full of conflicting advice. The best approach? Stick to evidence-based guidelines, eat a variety of whole foods, and be sceptical of diet trends that seem too good to be true. Remember, there’s no magic food or diet that works for everyone - balance, moderation, and listening to your body are key to long-term health. So, next time someone tries to convince you that carbs are evil or that detox teas will change your life, you’ll know better!