Most nutrition myths take a grain of truth and turn it into a rule: all fat is bad, carbs make you gain weight, fruit has too much sugar, you need a detox. The evidence points to something simpler. The overall pattern of what you eat matters far more than any single food, nutrient or eating time. Here are ten common myths and what the research actually says.
Myth 1: All fat is bad for you
Fat was blamed for decades, but newer research has changed the picture. The Harvard T.H. Chan School of Public Health notes that healthy fats are necessary and beneficial, and that the type of fat matters more than the total amount. Unsaturated fats from vegetable oils, nuts, seeds and fish lower disease risk. Trans fats are harmful even in small amounts, and saturated fats are best kept in moderation.
One problem with the low-fat era: when manufacturers took fat out, they often added refined carbohydrates instead. Harvard recommends replacing red meat and butter with fish, beans, nuts and healthy oils rather than refined carbs.
What to do: cook with canola or olive oil, add a handful of nuts or seeds to meals, and eat fish once or twice a week.
Myth 2: Gluten-free is healthier for everyone
A gluten-free diet is essential for people with celiac disease. The U.S. National Institute of Diabetes and Digestive and Kidney Diseases explains that people with celiac disease need to follow a gluten-free diet for life, ideally with help from a registered dietitian so they still eat a balanced diet. Some people without celiac disease also feel better avoiding gluten.
For everyone else, there is no evidence that cutting gluten is healthier in itself. Gluten-free packaged foods can be lower in fibre and sometimes higher in sugar or fat to improve texture. Whole grains such as whole wheat, barley and oats provide fibre, B vitamins and minerals.
What to do: if you suspect a problem with gluten, see your doctor before cutting it out, because testing for celiac disease is more accurate while you are still eating gluten.
Myth 3: Carbs make you gain weight
Carbohydrates are the body’s main energy source. The issue is the type and amount, not carbs themselves. Vegetables, fruits, legumes and whole grains come with fibre that helps you feel full. Refined carbs such as white bread, pastries, sugary cereals and sweetened drinks are easy to overeat and digest quickly.
Low-carb diets help some people lose weight, mostly because they cut out many highly processed foods and reduce total intake. They are not the only way, and they can be hard to sustain.
What to do: fill a quarter of your plate with whole grains or starchy vegetables, and choose whole grain versions when you can.
Myth 4: Fruit has too much sugar
The sugar in whole fruit is not the sugar health agencies want you to cut. The NHS explains that sugar found naturally in milk, fruit and vegetables does not count as “free sugars,” the type most people eat too much of. Free sugars include sugars added to foods and drinks plus the sugars in honey, syrups and fruit juices and smoothies.
Whole fruit also comes with fibre, water, vitamins and minerals. Juice is a different story: the NHS suggests limiting fruit juice and smoothies to no more than 150 ml a day.
What to do: eat fruit whole, enjoy a small glass of juice with a meal if you like it, and make water your main drink.
Myth 5: Eating after 7 p.m. causes weight gain
There is no magic cut-off time. What tends to cause trouble is what and why people eat late at night: large portions, snacks eaten in front of a screen, or eating out of boredom or tiredness rather than hunger. Eating close to bedtime can also disturb sleep for some people.
What to do: if you are genuinely hungry in the evening, choose a small snack such as plain yogurt with berries, a piece of fruit with peanut butter, or a glass of milk. If late-night eating is more about stress or habit, our guide to mindful eating can help.
Myth 6: You can’t get enough protein from plants
Most people can meet their protein needs with plant foods. Canada’s Food Guide encourages choosing plant-based proteins more often. Beans, lentils, chickpeas, tofu, tempeh, edamame, nuts, seeds and whole grains all provide protein. You do not need to combine specific foods at the same meal; eating a variety over the day covers your amino acid needs.
What to do: swap meat for lentils or beans in one or two meals a week, such as chili, soup or tacos.
Myth 7: Fresh produce is always better than frozen
Frozen fruits and vegetables are usually picked ripe and frozen soon after, which preserves most of their nutrients. They are often cheaper, last longer and reduce food waste. Canned options count too; choose ones with no added salt or packed in water or their own juice.
What to do: keep frozen vegetables and berries on hand for quick stir-fries, soups and smoothies.
Myth 8: Healthy eating is always expensive
Some health foods are pricey, but many of the most nutritious foods are budget-friendly: oats, dried or canned beans and lentils, eggs, frozen vegetables, carrots, cabbage, bananas, apples, potatoes and plain yogurt.
- Plan meals for the week and shop with a list.
- Buy staples in bulk and choose store brands.
- Cook once, eat twice: make a big pot of soup or chili and freeze portions.
- Buy produce in season or frozen.
Myth 9: You need a detox or cleanse
Your liver, kidneys, gut and lungs remove waste products all day without help. The U.S. National Center for Complementary and Integrative Health reports that a 2015 review found no compelling research to support detox diets for weight management or removing toxins, and that juicing and detox diets can cause initial weight loss from low calorie intake but tend to lead to weight regain once a normal diet resumes.
What to do: support your body’s own systems with water, fibre-rich foods, regular activity and enough sleep. Skipping alcohol helps too.
Myth 10: Snacking ruins your diet
Snacks can be a helpful bridge between meals, especially if long gaps leave you ravenous and overeating at dinner. The difference is in the choice. A snack that pairs protein or fat with fibre, such as apple slices with cheese, hummus with vegetables, or a small handful of nuts, keeps you full longer than chips or cookies.
The same goes for meal timing in general, including intermittent fasting. Some people find that a set eating window helps them eat less overall, while others find it leads to overeating later. The best schedule is the one that keeps you comfortable, energized and able to make good choices.
When to check with a professional
See your doctor or a registered dietitian if you think you have a food intolerance or celiac disease, have a condition such as diabetes, kidney disease or heart disease, or are considering a major diet change. If thinking about “good” and “bad” foods is causing you anxiety or guilt, speak with a healthcare provider or contact NEDIC (nedic.ca).
Key takeaways
- Choose unsaturated fats; limit trans and saturated fats.
- Go gluten-free only if you have a medical reason.
- Pick whole grains and fibre-rich carbs over refined ones.
- Whole fruit is not the problem; added sugars and large servings of juice are.
- Frozen and canned produce are nutritious, affordable options.
- Skip detox products; focus on water, fibre, activity and sleep.