10 Common Diet Myths That May Surprise You

How many times have you heard about a new health or diet trend being advertised and felt compelled to try it? These diet trends use all the right medical jargon to make it seem legitimate, and seem to make sense scientifically. But unfortunately, they are not always true, which is why these common diet myths need to be busted.

It can be hard to know what works, or what’s right or wrong when being overwhelmed with tips and advice about health and weight loss. With so much (often misleading) information found on Google, written by a non-professional or some so-claimed health guru, it’s hard to know who to trust. But just because a newspaper prints an article or celebrity endorses a health guru does not make them an expert. If you are unsure who to trust, then look for information on medical sites such as the NHS, or better yet, ask an expert. Dietitians are experts in nutrition and only advise on evidence-based information. Let’s find out which common diet myths have made it onto the list and find out what the experts have to say about it.

Myth 1: Fruit has Too Much Sugar

This is a common diet myth that dietitians here far too often. You may be feeling a need to avoid sugar for weight loss or other health reasons. But avoiding fruit because it contains sugar is a big no-no. Before you decide on cutting out any food or food group, ask yourself what other benefits these foods have to offer and if cutting it out is worth it. Avoiding or limiting processed sugars such as cakes and biscuits is a good choice to make. But when it comes to fruit, you aren’t only cutting out sugar. You are losing out on important nutrients too. These include fibre, vitamins, minerals and phytonutrients.

Apart from these nutrients, the natural sugar found in fruit (and dairy too) is important for brain function and to fuel our cells. Fruit is also the exception to your daily sugar intake. If you are going to have any sweet food, fruit is a good first choice. No one should be avoiding fruit, unless you have an illness or disease where limiting this is recommended. Overall, you should be aiming for 5 fruit and veg per day minimum, but ideally more (1).

Myth 2: Being Skinny means Healthy

Magazines often give us the impression that being super skinny is healthy. But this is not necessarily the case. Yes, having a healthy weight and BMI (body mass index) is important for your overall health and lowering your risk of certain lifestyle diseases. But a skinny person can also be at risk of health problems such as high blood pressure, high cholesterol and cancer. Lifestyle factors such as eating a diet high in unsaturated fats can affect cholesterol no matter what your size. Smoking is unhealthy for everyone, and can put anyone at risk of getting cancer or high blood pressure.

Some skinny people can get away with eating junk food on a regular basis, hardly ever having enough fruit or vegetables and grains. Possibly due to genetics or other factors, they don’t seem to gain weight. But this doesn’t mean they are healthy and doesn’t mean if you are skinny, you can eat whatever you want. Some very skinny people may have an eating disorder, which is a serious health concern.

If you want to be as healthy as can be, aim to have a healthy BMI and weight, and eat a balanced diet including all food groups. Avoid unhealthy processed foods, smoking and alcohol as much as possible and aim to do at least 150 minutes of physical activity a week.

Myth 3: Cutting Carbs for Weight Loss

Another common diet myth is cutting out carbs to aid weight loss. Any diet fad that recommends cutting out a certain food or an entire food group should raise a red flag. Each food group offers important nutrients that the body needs regularly. Cutting out carbs will be depriving yourself of certain vitamins, minerals and fibre that are needed for your health. This includes your immune system, bone health, gut health and even your skin to name some benefits. Not to mention that fibre is one nutrient that helps keep you satisfied and full and helps with weight loss. So why would you want to cut this out?

Ditching the carbs may mean having more protein and fats instead. This is likely to result in constipation (due to the excess protein and lack of fibre) or a raised cholesterol level along with other harmful health outcomes. Cutting out carbs is usually not sustainable to follow long term. Once you go back to eating how you did before, you are likely to put on more weight than when you started.

If you truly want to lose weight and keep it that way, there are some safer, more sustainable choices you can make. Try to include all food groups daily, limit unhealthy processed carbs such as biscuits (replace these with some fruit or other high fibre food), and reduce your over meal portions instead. In combination with a healthy intake, regular physical activity is essential too.

Myth 4: Superfoods give Super Nutrition

Whoever came up with the buzz word “Superfood” has a lot to answer for. It purely is a buzz word created to grab people’s attention and is certainly not a word used to describe a food group in the medical field. The typical list of superfoods includes certain fruit or veg such as blueberries, broccoli and kale, protein such as eggs, salmon and nuts, and carbs such oats. It is not to say that these foods don’t provide super nutrition, as they are very healthy. But what makes these foods any more special than all the other fruit, vegetables, grains and healthy proteins?

If a superfood title did exist in the medical world, it would most likely be awarded to all fruit and veg, all complex carbs, and many types of protein. All berries are rich in antioxidants, vitamins and minerals like blueberries. They are all low in calories and make them a perfect light, sweet snack. And what did that poor pear or banana ever do to be left off the list? Pears are very high in fibre, and bananas rich in potassium and magnesium (among other nutrients), which blueberries don’t contain that much of. Oats may be a high fibre starch rich in vitamin B’s, but so is wholegrain rice and quinoa. Salmon is rich in omega 3 fatty acids, as is tuna, sea bass and chia seeds. Don’t always be fooled by a headline.

Myth 5: Replace Regular Sugar with Unrefined Sugar

No matter what it’s colour or process, sugar is sugar. Except sugar that occurs naturally in a food you eat, such as fruit or dairy, adding any extra sugar to a food or drink (including foods with already “added sugar”) counts towards your daily sugar intake. According to the NHS, adults should not have more than 30g (7 sugar cubes) of sugar per day (2). This includes white and brown sugar, any foods added to food or drinks (such as chocolate), coconut sugar, honey, syrup, agave, smoothies and unsweetened fruit and vegetable juice.

Choosing to add honey to your tea instead of sugar still counts toward your intake for the day. Switching white sugar for brown sugar is no different, it is still sugar, but a different colour that underwent a different process. It is not the same as choosing brown bread over white bread. No matter the type, it will count toward your daily sugar intake. An excess of any added sugar is unhealthy and can still contribute to weight gain. So don’t be fooled by this common diet myth.

Myth 6: Juicing to Detox, Cleanse or Lose Weight

Common diet myth number 6 on the list has been around for some time. Many people still believe that juicing will help cleanse and detox their body. But in truth, your body doesn’t need you to perform the task of a detox and it certainly doesn’t need a break from important nutrients.  Firstly, detoxing is the role of your liver and kidneys, not your juicing machine. These organs are responsible for detoxing. They eliminate toxins and an excess of certain nutrients that the body doesn’t need. At least, as much as they can. By juicing, you are taking away their job. But your liver can also store certain nutrients to save for a later time. But if you have too much (for example vitamin A), this can potentially be very harmful.  The best way you can detox, is by cutting out alcohol, smoking and unhealthy processed foods. By limiting or avoiding these, you are giving your liver and kidneys a chance to recover.

You may think that by juicing, you are also getting in an abundance of extra vitamins and minerals. Although your input of these nutrients are high, your body can only utilise so much and the rest will be expelled or stored (within reason). But apart from vitamins and minerals, you are depriving your body of essential macronutrients such as protein and fibre, which your body does not need to detox from. Is starving your body of important nutrients really worth it? 

As for weight loss, of course you will initially lose some weight. As that’s what happens when you deprive your body and starve yourself. However, it is not sustainable long term, and most of the weight you lose is water and muscle mass (not fat). Once you go back to “normal eating”, that weight will come back pretty quickly. So you are better following a sustainable healthy eating lifestyle that is balanced along with exercise if you are serious about losing weight and keeping it off. 

If you want to detox, let your organs do their job, and make it easier for them by eating balanced, healthy meals and ditching alcohol and smoking instead. Try filling up your plate with more fruit or veg to get in the extra nutrients and fill you up so you are less likely to snack on unhealthy foods. If you really want to have an all-fruit or veg drink, blend up the whole edible part instead, so you are at least getting in the fibre too. If this is to replace a meal, be sure to add in some protein so you are missing out.

Myth 7: Gluten-free is Healthy and Aids Weight loss

Unless you have coeliac disease or a gluten intolerance, having gluten-free foods is not necessarily a healthier choice than a gluten-containing food. 

Gluten is a protein found in certain grains such as wheat, rye and barley (3). It is natural, and for someone without a health reason, it is harmless and should be your preferred choice.

In the majority of cases, having gluten-free products can be worse for you than the gluten option.  When gluten is removed from a food, other ingredients are needed in its place. Often these foods are more processed and contain more fat, salt, sugar and refined starch. These ingredients certainly don’t seem like the answer to weight loss or being more healthy.

If you want to eat gluten-free, choose foods that naturally don’t contain gluten. Or make sure to check the ingredients list of any gluten-free food you are considering adding to your basket to see if it is as healthy as you think.

Myth 8: Drink 8 Glasses of Water a Day

Drinking 8 glasses of water a day is a general recommendation to ensure people stay hydrated. The problem with this average is that most people are not the same size and a one-size-fits-all approach doesn’t quite work when it comes to hydration. For someone weighing 50kg (110 lbs), this may be too much compared to someone weighing 100kg (220 lbs) where 2 litres is too little. Different amounts are also needed depending on someones extra losses such as sweating.

Usually, an accurate amount is to calculate 35ml per kilogram body weight. But then you have to take into account other losses too which can make it confusing. The simplest way to know if you are getting in enough fluid is to check your urine colour. If it is dark yellow (like it is in the morning), then you are dehydrated and need more fluid. If it is clear, almost the colour of water, then you are well hydrated.

Myth 9: Fats are Bad for you

It seems to make sense that eating fat will make you fat, but this is not the full story. Yes, eating large amounts of fat can lead to weight gain, but so can eating too much of other foods. Fat is an important macronutrient needed by the body. It is made up of essential fatty acids that the body cannot make on its own. It is important for the absorption of fat-soluble vitamins such as vitamin A, D, E and K, as well as for energy. Any fat not used for energy will be stored as fat, a backup energy supply for the body. The same applies when eating too much protein and carbohydrates. Unfortunately, eating too much of any of these macronutrients will be stored as fat. If this supply gets too big, it results in excess body weight. But this doesn’t mean you must avoid these foods.

Each food group has different, but important roles to play. So it is vital to never cut out any of these out. When it comes to fat, it is more important to care about the type and amount you consume. The main forms of fat include saturated and unsaturated fat (4). Most fats contain both of these types, but it is important to try and have foods with mostly unsaturated fats. Saturated fats (mostly from animal sources, but also coconut and palm oil) can cause an increase in cholesterol levels, increasing the risk of heart disease. Although some studies seem to suggest otherwise. Whereas unsaturated fats (for example avocado, olive oil and oily fish) are healthier and can help lower cholesterol levels, among other benefits. The main fats to avoid are trans fats which have been proven harmful to health. Fortunately, these have been removed from many products in the UK.

To summerise, not all fats are bad, but some are. It is important to limit your intake of saturated fats daily. Government recommendations are 20g per day for women and 30g a day for men. You can buy low-fat options to help wit this. But be aware that some of these foods are higher in sugar (for example yoghurt) and “lower fat” is not the same as “low-fat”. Check the label to make sure this is truly low fat. Low-fat is 3g (3%) of total fat per 100g or less (and 1.5g or less per 100g saturated fat). When choosing fats, opt for healthier fats such as unsaturated fats instead, but limited amounts of fat on the whole.

Remember, fat is still fat at the end of the day. If you consume too much, it can lead to weight gain. Like with eating too many carbs or protein, any excess will be stored as fat. Aim to control the overall portion sizes of your meals, over cutting one food group out in its entirety.

Myth 10: Eating Often will Boost your Metabolism

While this last common diet myth is not entirely a myth, there are some misconceptions that are important to note. Firstly, your metabolism is and process that takes place in your body where energy is expended and calories get burned (5). It is constantly working all day and night, even when you are asleep. Eating requires digestion to take place, which increases the workload of your metabolism slightly. It works harder and burns some extra calories. When eating more frequently, digestion is taking place more often. But eating smaller, frequent meals, compared with larger, less frequent meals may take up the same amount of energy to break down.

Metabolism speed comes mostly from our genes. Some people have a very fast metabolism and can eat larger amounts of food without gaining weight. Others have an average or slow metabolism and gain weight if eating too much. As we age, metabolism slows down too, even if this was once fast. Eating smaller portions can help with weight loss. But that is because of the overall amount of food and calories consumed. It is not only about calories but the type of food too. A slice of white bread may be lighter in calories than wholegrain, seeded bread. But there is more fibre in wholegrain bread which is harder to digest and can help with fullness. It can also help in stabilising blood sugars.

If you eat small portions that contain foods that are harder to digest such as fibre and protein, then yes, your metabolism will work a bit harder to digest these. But the amount of calories burned through this process will be far from meeting the calories in the food eaten. There is nothing wrong with eating more frequently and having smaller meals, as there is nothing wrong with eating 3 main meals a day. The key lies in portion control, the type of food you choose and doing regular exercise. Fibre-rich foods such as fruit, veg and wholegrains will keep you fuller for longer, as will protein. Processed and refined sugary foods can lead to weight gain. It also may leave you with cravings or feeling hungry and overeating throughout the day.

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