VERIFIED CONTENTAuthor: Aleksandra Żyłowska-Mharrab, dietitian, food technologist, educator
Some of the nutritional myths stem from erroneous scientific hypotheses prevalent before they were truly confirmed. Others are made by vendors of diets and wonder solutions to weight problems. And still others came out of nowhere, but fell on such fertile ground that no one verified their truthfulness. We debunk the most common of them.
There are tons of myths around nutrition and weight loss today. Myths that contradict logic, myths challenged by science, but still spreading and repeated over the next generations. Yes, some of the nutritional myths are very old, but still live. It's time to deal with the biggest myths in the world of dietetics.
Myth1 - you get fat by eating after a certain hour
"Please don't eat after 6pm" I heard from an endocrinologist who diagnosed me with hypothyroidism. Have you also heard it from a specialist, and not only from a friend in the store? I was at the end of my nutrition studies then and I knew that at 6 p.m. your metabolism does not turn off like light - at the flick of a switch. However, how many people do not know about it and really try not to eat after 18?
I will never understand why just after 18, the consumption of calories would be much slower than, for example, after 20 or after 16. Let us emphasize for the sake of clarity, you get fat from consuming excess calories. Weight gain is influenced by the type of food the calories come from. Gaining weight is influenced by hormonal and genetic predisposition. But weight gain is not affected by the mythical 18 o'clock.
The time of the last meal should be adjusted to the lifestyle and times of activity. Of course, it would be good if each of us lived in harmony with the circadian rhythm, could get up at dawn and go to bed after sunset, adjusting the times of activity and meals to the availability of daylight. However, the modern world does not work that way.
We work at different hours, in winter the day is very short in Poland. Therefore, it is most rational to adjust the last meal to your lifestyle. Dinner should be light and easy to digest, as it is better to go to bed on an empty stomach. But if you are an owl, you are a person in the eveningactive and you go to bed at 1am, dinner at 9pm won't make you fat.
Myth2 - Fat is unhe althy
Today it is known that the "fat theory" according to which saturated fat and cholesterol from food are responsible for heart disease and the obesity epidemic is not true. It is known that it was based on selective studies to confirm it. It is known that the American scientific council, which developed dietary recommendations to reduce the consumption of animal fat and cholesterol, was selected from the supporters of the "fat theory."
It is known that reducing animal fat in the diet does not reduce the risk of heart disease and obesity. On the contrary, the risk may increase when fat is replaced with carbohydrates. You know. Scientific research has completely discredited the "fat theory", yet official dietary recommendations still do not directly speak of increasing fat intake in favor of reducing carbohydrate intake.
Since the beginning of the 1980s, that is, since the introduction in the United States of the recommendations recommending a reduction in the consumption of red meat, butter, whole milk, eggs, cream, cheese and other sources of animal fat, the obesity epidemic has started for good .
12% of Americans were obese in 1950, 15% in 1980. And in 2000 - 35%.
In Great Britain, the number of obese people increased from 6% of the population in 1980 to nearly 20% in 2000. Case? Currently, specialists say no. Swapping eggs for muesli and pork loin for rice contributed significantly to this.
How did it all start? It turns out that the "fat theory" is the result of one doctor's big ego. A very important physician, Ancel Keys - responsible for the he alth of US President Dwight Eisenhower. The president, after a heart attack in 1955, made public his illness, which at that time was affecting masses of men.
His private physician then recommended reducing saturated animal fat and cholesterol as a means of preventing atherosclerosis and heart disease, citing a correlation between dietary fat and cardiovascular events (today it is known that the data were biased ). Eisenhower followed the instructions closely until his death. He died of a heart attack.
The "fat theory" at its origins had many opponents, especially among British scientists. The greatest was John Yudkin, who directly criticized the "fat theory", claiming, inter alia, the topic of the correlation of heart disease with sugar consumption. Ancel Keys, very charismatic and popular, completely discredited the discoveries of Yudkin andruined his career. Only because Yudkin has shown evidence against the "fat theory." From Yudkin's time to the early 2000s, no one important dared to loudly challenge the "fat theory".
This is how we lived for several dozen years with the myth about the harmfulness of fat repeated by global organizations. And it is not known how long it will take to repair the effects of duplicating this myth.
Myth3 - You have to eat breakfast as soon as possible after waking up
Breakfast is the most important meal of the day. They say. And there is something to it, because indeed children who do not eat breakfast tend to have poorer academic performance more often, and in some study groups people who completely skip breakfast tend to have poorer food choices during the rest of the day.
Which probably results from hunger and catching anything to eat. At the same time, studies in other populations have shown that eating or not eating breakfast basically does not affect anything. So, when asked "do you have to eat breakfast?" the answer is "it depends." Generalizing from the available knowledge, it can be said that from a nutritional point of view it is good to have breakfast, or at least that it does not hurt anything.
Another breakfast myth revolves around how quickly you need to eat breakfast when you wake up. As soon as possible? Until an hour? I will not count how many times I have heard nonsense about how the stomach begins to digest itself on an empty stomach, because it produces hydrochloric acid or digestive juices in general.
This theory is completely irrelevant, because first of all, the gastric mucosa is constructed in such a way that the strongly acidic content does not damage it. Second, why should this "self-digestion" begin when you wake up, and not when you sleep at night, when you also have an empty stomach? So - your stomach doesn't start digesting if you don't eat breakfast shortly after getting up.
What about slow metabolism if you don't eat breakfast? This is also a myth. Studies in recent years focusing on the number, frequency and caloric content of individual meals have shown that the metabolic rate does not depend on whether you eat breakfast immediately after getting up or maybe 3 hours later. Also, skipping breakfast does not make you gain weight faster and increase your risk of obesity.
The indicator of when to eat breakfast should be the feeling of hunger. Are you not hungry? Do not force yourself to eat.
Myth4 - 5 small meals a day speeds up metabolism
Probably everyone heard about 5 small meals every 3 hours. You only lose weight this way. You just won't get fat. 5 small meals a day is a guarantee of he alth. Definitely? Definitely not.
The theory of the positive effect of 5 meals on body weight was derived from several epidemiological studies in which such a relationship was observed. The world of nutrition, however, has completely ignored the fact that most studies have found no relationship between meal frequency and weight gain / loss, and the research evidence that has shown such an association is weak.
Scientific publications already in the 90s of the twentieth century tried to debunk this myth, but it crept into the mainstream to such an extent that I heard about 5 meals during lectures in college and most nutritionists recommended this diet for years. Calorimetric studies analyzing the body's total energy expenditure over 24 hours showed that it was independent of the frequency of meals. So the metabolism does not accelerate when eating 5 meals a day and does not slow down when eating 3 meals.
In addition, new research shows that eating rarely lowers blood glucose levels and facilitates appetite control, which may benefit weight management in the long term, and lowering meal frequency to 2-3 times, in combination with other factors, may affect positive for he alth by reducing inflammation, increased resistance to autophagy and stress, and modulation of the gut microbiome.
Man is not made for continuous digestion. Periods of hunger have a very positive effect on he alth, and frequent eating is a very young idea related to the industrial revolution. Curiosity. Medieval Teutonic Knights at the castle in Malbork ate 2 times a day - the first around noon and the second in the evening.
Myth5 - potatoes are fattening, sweet potatoes - not
People who are slimming often tell you that they do not eat potatoes (and bread), because potatoes make you gain weight. For several decades, potatoes have been equated with a "non-dietary" or fattening product. If we want to classify products as fattening or non-fattening, let's think about what the fattening ones would have in them?
In my opinion - high calorific value per 100 g, high content of simple sugars or added fats, high glycemic load. These are the factors that contribute to weight gain.
And what do potatoes have in them? 77 kcal in 100 g (little), 0.8 g of simple sugars (very little) and the glycemic load of 8 (low, because less than 10). So what can be accused of them? Probably just that they are a source of carbohydrates. But man needs carbohydrates, and their skilful inclusion in the diet (i.e. not sandwiches for breakfast and dinner + potatoes for lunch) does not make you fat.
In addition, potatoes are still vegetables, despite the fact that they are starchy, i.e. they contain fiber and water, and a set ofvitamins and minerals. By comparison, 100 g of cooked potatoes provide fewer calories and carbohydrates (77 kcal and 19 g of carbohydrates) than 100 g of cooked rice (115 kcal and 25 g of carbohydrates).
A few years ago, in response to "fattening" potatoes, "non-fattening" sweet potatoes became popular. Which is marketing in its purest form. How else can you name the provision of excellent weight loss benefits compared to potatoes, if sweet potatoes have a higher caloric content, a higher content of carbohydrates and simple sugars, and a higher glycemic load than potatoes?
Let's take a look at the nutritional benefits of raw potato and raw sweet potato. The only advantage of sweet potatoes seems to be higher fiber content and slightly more minerals. But if you chose a more "fattening" product, it would be sweet potatoes, not potatoes.
| Nutritional value per 100 g | ||
| Nutrient | Potatoes | Sweet potatoes |
| Energy | 77 kcal | 114 kcal |
| Carbohydrates | 18.4 g | 26.8 g |
| Starch | 15.4 g | 16.8 g |
| Sugars | 0.8 g | 5.6 g |
| fiber | 2.2 g | 4 g |
| Protein | 2 g | 2.1 g |
| Vitamin C | 19.7 mg | 3.2 mg |
| Vitamin B6 | 0.3 mg | 0.3 mg |
| Magnesium | 23 mg | 33.2 mg |
| Copper | 0.1 mg | 0.2 mg |
| Manganese | 0.2 mg | 0.3 mg |
| Potassium | 421 mg | 448 mg |
Myth6 - Eggs Increase Cholesterol
Eggs, cream, butter, red meat… They contain a lot of cholesterol! Avoid them if you want to keep your heart he althy and prevent atherosclerosis! Unfortunately, many nutritionists and doctors still repeat these words, recommending their patients a maximum of 2 eggs a week. And yes, it's true that eggs are among the richest foods in cholesterol. But! The body itself produces cholesterol in amounts that are many times greater than those that we are able to eat.
Cholesterol provided with food has very little effect on blood cholesterol levels. About 85% of the cholesterol in the human body is produced by the liver. The remaining 15% comes from food. Moreover, the liver increases the production of cholesterol when you eat it little and lowers it when you eat more cholesterol than average.
Doesn't meanis that high blood cholesterol is not something to be concerned about. It should, but the causes of this condition vary (e.g., genetic factors, damage to blood vessels resulting from chronic inflammation) and are not related to the number of eggs eaten per week. Unless we're talking about people who are hypersensitive to dietary cholesterol.