We’ve all grown up hearing the same food rules repeated so often they feel like gospel. Don’t eat after 8 p.m. Eggs will destroy your heart. Eat more carrots and you’ll see like a cat. The problem is, a lot of what passes for nutritional common sense has very little real science behind it. Food myths are nutritional concepts poorly justified or even contradicted by existing scientific evidence, yet individuals take them as the truth. Here are four of the most stubbornly persistent food beliefs that science has now firmly put to rest.
1. Carrots Will Improve Your Eyesight
Generations of parents have wielded this one at the dinner table, and it has survived remarkably intact. As children, many of us were told that eating our carrots would improve our eyesight. This notion dates back to World War II and a British propaganda campaign. Ultimately, it is a myth, but it is based on a sliver of truth. The Ministry needed to conceal the Royal Air Force’s new secret radar technology, so they attributed their pilots’ success at shooting down enemy planes at night to carrots. They claimed the pilots ate an abundance of carrots, which gave them superior night vision. It is unclear whether the Germans bought the carrot myth, but the British public generally believed it.
So what is the actual truth? There’s nothing magical about carrots alone – it’s the vitamin A within them that is so important for eye health. Vitamin A in normal, recommended quantities is essential for the maintenance of good vision. If a person is deprived of vitamin A for too long, the outer segments of the eye’s photoreceptors begin to deteriorate. However, night blindness is rare in the United States because most people in this country are already getting enough vitamin A from their daily diet. Binging on carrots would not improve most Americans’ eyesight. Once you have enough beta-carotene in your body, it will often no longer convert to vitamin A. The body naturally regulates against excess amounts of vitamin A to prevent accumulation of toxic levels.
2. Eggs Are Bad for Your Heart
For decades, eggs were cast as one of the great dietary villains, blamed for spiking cholesterol and clogging arteries. For many years, eggs have been unfairly blamed for high cholesterol and heart disease. The theory was that because eggs contain dietary cholesterol, they must be a major contributor to high blood pressure, high cholesterol, and cardiovascular disease. Eggs are a unique food that are high in cholesterol but low in saturated fat. Egg consumption recommendations have fluctuated over time due to the belief that increased intake of dietary cholesterol raises plasma LDL cholesterol and therefore cardiovascular disease risk. Research suggests it is saturated fat, rather than dietary cholesterol, that is implicated in this association, yet controversy over egg consumption remains.
The science has now shifted significantly. Eggs are finally being vindicated after decades of cholesterol-related blame. New research from the University of South Australia reveals that eggs, despite their cholesterol content, aren’t the dietary villains they’ve long been made out to be. Instead, it’s the saturated fats found in foods like bacon and sausage that actually elevate harmful LDL cholesterol levels. In a world-first study, researchers showed that eating two eggs a day, as part of a low saturated fat diet, can even help reduce LDL cholesterol. Across all three diets tested, increases in LDL levels were significantly related to saturated fat intake but not to cholesterol intake from eggs. In fact, people who consumed two eggs per day as part of a low-saturated-fat diet actually lowered their LDL levels.
3. Eating at Night Causes Weight Gain
The idea that calories consumed after a certain hour automatically turn to fat is one of those beliefs so widespread it feels like biology. If you have already consumed your calorie allotment for the day and continue to eat after 7 p.m., then yes, you’re consuming excess calories. However, there are many countries in the world where the standard dinner time is 9 p.m. or later. What’s more important are the types of foods and quantities you choose rather than what time you eat them. Weight gain happens when we eat more calories than we burn, whether they come from carbs, protein, or fats. The real issue tends to be what people actually reach for after dark.
When it comes to weight gain or loss, it is not the time of day that makes the difference – it’s what you are consuming. Most people tend to veg out on high-calorie foods while unwinding in front of the TV after a long, stressful day. Other researchers have found that eating at night leads to poor sleep quality, and that sleep has a big impact on late night snacking and weight gain. Chronic sleep deprivation or late bedtimes in adults can lead to weight gain, because adults tend to eat extra calories during late night hours. In other words, it’s the pattern of choices – not the clock – that is the real culprit.
4. Carbohydrates Make You Fat
The low-carb movement has been so dominant in diet culture that many people now treat bread like a health hazard. Carbohydrates are often seen as the enemy, but they’re not the villain when it comes to weight gain. Like anything, it’s all about balance and choosing the right kind. Weight gain happens when we eat more calories than we burn, whether they come from carbs, protein, or fats. The low-carb diet is a fad that has continued to make an appearance over the years and gives carbohydrates a bad reputation. Individuals who followed this diet had success with weight loss. But anytime anyone eliminates highly processed carbohydrate foods, such as chips, cookies, white bread and potatoes smothered in butter and gravy, they would be expected to have the same results.
Choosing high-fiber carbohydrates such as whole grains, fruits, and vegetables while limiting added sugars can help with feelings of fullness and is linked to more positive health effects, such as lowering the risk of heart disease and type 2 diabetes. Cutting out carbs entirely can mean missing out on essential nutrients like B vitamins, calcium, and dietary fiber. It can also lead to higher intakes of saturated fat, which increases chronic disease risk, and a negative relationship with food. The issue was never the carbohydrate itself – it was always the quality, quantity, and overall dietary context surrounding it.
