The biggest weight-loss myths debunked by a dietitian: Avoid these common mistakes if you want to get slim for summer – including the ‘light’ lunch that’s sabotaging your diet

Bread will make you gain weight, sushi is always a healthier option, and carbs are your worst enemy – these are just a few of the biggest misconceptions out there about weight loss. 

But these so-called ‘truths’ couldn’t be further from reality, according to accredited practising dietitian Kirby Sorenson.

Here, she tackles the top 10 myths about weight loss that could be holding you back, explaining why these ideas might actually be sabotaging your journey to better health and fitness.

1. Apple cider vinegar helps you lose weight

Forget what you’ve heard: apple cider vinegar won’t magically melt away kilos, detox your body or balance your pH levels. 

However, there is evidence it can help improve your body’s blood glucose response after a carb-rich meal, making it a helpful tool for managing blood sugar levels.

2. Sweet potato is healthier than other potatoes 

Many people believe sweet potatoes are healthier than white potatoes, but this isn’t entirely true. From a macronutrient standpoint, sweet potatoes and white potatoes are quite similar. 

While white potatoes have a slightly higher glycaemic index (GI), the difference is minimal and doesn’t have a significant impact. 

In terms of micronutrients, sweet potatoes have more vitamin A and vitamin C, while white potatoes are richer in potassium and iron.

Both options offer unique benefits, so you don’t have to choose one over the other.

3. Sushi is a healthy, balanced meal

Sushi is a popular go-to for a ‘healthy’ meal, but it’s not always as balanced as it seems. 

Many sushi rolls are predominantly rice, with only small amounts of vegetables and protein, making them primarily a source of carbohydrates with limited fibre, protein, and healthy fats – key components of a balanced meal. 

For a more nutritious alternative, try sashimi with edamame or Vietnamese rolls. 

Vietnamese rolls offer a good amount of fibre from fresh vegetables and often come with a generous portion of lean protein, making them a more balanced choice than typical Aussie sushi rolls.

4. Carbs are ‘bad’ and the reason you’re gaining weight 

‘I need to cut carbs’, ‘Carbs are the enemy’, ‘I’m going low-carb’.

These are phrases Kirby hears a lot as a dietitian specialising in weight loss, especially from people who are on a health kick.

But the reality is carbohydrates play a crucial role in a healthy, balanced diet.

Carbohydrates, along with protein and fat, are an essential macronutrient that your body needs for energy. For most healthy individuals, carbs should make up about 45 to 65 per cent of daily calorie intake.

Carbs are so important that cutting them out just isn’t a sustainable approach. Instead, try focusing on choosing healthier carbs over less nutritious options.

When deciding what carbohydrates to eat, it’s key to know the difference between simple and complex carbs. Here’s a breakdown:

Simple carbs – think sugar, sweets, fizzy drinks and foods made with white flour – have a basic structure, usually one or two sugar molecules, and so are quickly digested and absorbed, leading to a rapid spike in blood sugar.

These quick bursts of energy often lead to blood sugar spikes and crashes, which can make you feel tired or hungry soon after eating.

By contrast, complex carbs comprise longer chains of sugar molecules, which take longer to break down, resulting in a slower release of sugar into the bloodstream.

Examples include vegetables, legumes (beans, lentils, chickpeas etc.) whole grain (brown rice, oats) and other fibre-rich foods. These not only keep you fuller for longer, but are packed with vitamins and minerals.

Remember: eliminating carbs entirely can leave you feeling tired or low on energy, which can often lead to overeating or snacking later in the day. 

5. Eating bread makes you gain weight

No, bread alone does not make you gain weight.

No single food is inherently linked to gaining weight. Weight gain happens when you’re in a calorie surplus – meaning you consume more calories than your body burns.

If you eat enough bread to exceed your calorie needs, then yes, you might gain weight. But you can also enjoy bread and still lose weight, as long as you’re in a calorie deficit.

6. Snacking can derail weight loss

This isn’t necessarily true. In fact, snacking can actually assist people with weight loss if it helps to satisfy an individual’s hunger while they are waiting for their next meal. Avoiding snacking when you are feeling genuinely hungry can lead to binge eating, poor food choices or having oversized portions at meals. 

Snacking can, of course, negatively affect weight-loss goals, especially when it’s done mindlessly or when the choices are primarily unhealthy.

But if you opt for snacks that are high in fibre and protein and only eat them when you are actually feeling hungry, you should be fine.

The key is to ask yourself before you snack: do I actually want this because I need it, or am I just feeling bored?

7. Healthy foods are always expensive

No, healthy foods are not always the more expensive option. Planning meals ahead of time and drawing up a weekly grocery list can help you to make healthier choices on a modest budget.

Here are some ideas on how to make healthier foods more affordable:

• Choosing fruits and vegetables that are in season
• Buying frozen or tinned foods, including fruits, vegetables, pulses and canned tuna or salmon. These products are just as nutritious as fresh – but do make sure to read the ingredients list to check there is no added sugar and/or salt
• Compare prices (check price per kg) and look out for specials and discounts
• Buying in bulk can often be cheaper than buying single serves. This is especially true for items like rice, pastas, oats, nuts and seeds
• Avoid shopping while hungry to reduce impulse purchases
• Choose home brand options. These items often have similar nutritional content to branded options and can be half or even quarter the price 
• Look at other supermarkets besides Coles and Woolworths. Shopping at a budget chain like Aldi can shave a significant amount of your weekly grocery bill while still buying the same items

Another point: Some expensive products that are marketed as health foods are actually not that essential for a healthy diet. You could easily eat a balanced diet without half the products that populate the ‘health food’ in your local supermarket.

8. Fruit contains too much sugar 

Wrong. Fruit is incredibly nutritious, packed with essential vitamins, minerals, and plenty of fibre. 

The natural sugars in fruit provide a healthy source of energy and are very different from processed sugars found in sweets, chocolate bars and cakes. 

9. Small, frequent meals eaten throughout the day will ‘boost’ your metabolism

Meal frequency doesn’t significantly impact your basal metabolic rate or overall calorie expenditure if your total calorie intake remains the same.

For better metabolic health, focus on avoiding constant calorie deficits, getting enough sleep, and incorporating weightlifting into your routine.

10. Fats should be avoided

Fats are essential for health and should not be avoided. The body requires a minimum amount of dietary fat – about 0.5g per kilogram of body weight, or roughly 20 per cent of daily calorie intake – to support various vital processes. 

Healthy fats help prevent coronary heart disease, assist in hormone production, and enable the absorption of fat-soluble vitamins (A, D, E, K). They also play crucial roles in cell health, immune function, nerve transmission, brain health and managing inflammation.

It’s important to understand that not all fats are the same. Only polyunsaturated fats (omega-3 and omega-6) are essential, and they should make up about 10 per cent of your daily energy intake. Other fats include monounsaturated fats (beneficial but not essential, as the body can produce them) and saturated fats (which should be limited to less than 10 per cent of you daily energy intake).

Sources of polyunsaturated fats include fatty fish (salmon, mackerel, sardines, trout, tuna); nuts and seeds; plant and vegetable oils; and some meat and eggs.

Monounsaturated fats, which can support cholesterol levels and overall cardiovascular health, can be found in foods such as olive oil, avocados, nuts and seeds, and olives.

Saturated fats – the type that should only be consumed in moderation – are found in processed meat, dairy, palm oil, fried foods and sweets.