What is a calorie?

On any product package today we see the word “calorie content” – and the numbers opposite it. I wish we hadn’t. Because finding out that a tiny (as it seemed) eclair you just ate cost you 700-plus calories is truly painful. Scary thoughts immediately come to mind that the abstract figure on the package will become a very real figure on the scale by evening, and all the pleasure of a delicately beloved pastry evaporates instantly.

But what does that dreaded word “calories” really mean? How, in reality, does the calorie content of foods affect our weight and well-being? How many calories do we need to eat per day to maintain or lose weight? And why didn’t a low-calorie diet that turned my neighbor into a slender girl work in my particular case? To learn more about nutrition and fitness, visit Built By Beauty.

A calorie is the amount of thermal energy it takes to heat one gram of water by one degree Celsius at standard atmospheric pressure. The energy value of food is usually measured in larger units – kilocalories, 1 kcal is 1000 calories, and in this case we are talking about a kilogram of water.

That is, calories are the units of energy contained in food, which our body can either use immediately or put away in reserve.

How do you measure the calorie content of food?

In fact, to understand the connection between an abstract kilogram of water and a real eclair, which contains, say, 790 kcal, is quite difficult to comprehend. And it’s not easy to explain on the spot how calories are counted. Today foods are not heated, but burned in a special chamber, measuring the amount of energy they release with a device called a calorimeter. But even more often they are chemically broken down into proteins, fats and carbohydrates, and their specific weight and total calories are counted (you can read more about how to count calories here). Calorie values for different groups of products are well known, even in the 1970s, they were experimentally obtained by American scientist Wilbur Atwater, who is considered the father of nutrition: the calorie value of carbohydrates – 4 kcal/g, protein – 4 kcal/g, fats – 9 kcal/g.

Interestingly, the general population only became aware of the concept of calories in the 90s of this century. Calorie counting became part of the idea of the U.S. government to combat weight problems, which in the U.S. is particularly acute: in 1990, manufacturers were required by law to write the number of calories on the package of any product. This practice caught on in the U.S. and then worldwide.

How many calories does a person need to live?

There is a concept of basal metabolism, which is the minimum energy expenditure that the body needs to maintain vital functions: breathing, digestion, etc. Roughly speaking, this is the energy expenditure of an average person who is awake (energy expenditure decreases in sleep), but also does nothing, and lies on the couch and does not move a hand or a leg. And, in scientific language, he is in a state of thermal neutrality: that is, he is neither hot nor cold. The value of basal metabolism for adult women with normal weight is about 1330 kcal, for adult men with normal weight – about 1680 kcal. That is, to maintain basic life activity it is enough to eat, in the crudest approximation, two eclairs a day.

It is clear that any movement will require you to spend more. In addition, each person’s actual calorie requirement is strictly individual and depends on gender, age, body weight, lifestyle, proportion of muscle and fat tissue and other factors. There are many systems for calculating calories, in which the basal metabolic rate is multiplied by individual coefficients reflecting these indicators, but this is quite a complicated task, with which it is better to consult a specialist.

Another figure, the “gold standard” daily measure of calorie intake, which is found in the medical literature, is the figure for a person of average activity level. For women it is 1600-1800 kcal, for men it is 2000-2500 kcal. But this is also such an “average hospital temperature,” measured more for statistics than as an individual figure for real people. Although, in order to keep within limits and not to overeat, these figures can be kept in mind.

How much do I need to reduce my calorie intake to lose weight?

There is a famous “3500 kcal rule” that everyone who has ever tried to lose weight probably knows. It sounds like this: in order to lose 500 grams of body weight in a week, you need a deficit of 500 kcal in the energy value of your daily diet. If you multiply 500 kcal by 7 days, you get exactly 3,500 kcal per week, which, if subtracted from our diet, should automatically mean minus half a pound on the scale. This equation has been around in nutrition science since the 50s, and it should have been broken down and forgotten about long ago, but it can’t. Physiology is not mathematics; it does not lend itself to calculations in absolute terms. Our body is cunning, it believes that fat accumulation is necessary and diligently puts it away for a rainy day. It’s a kind of survival insurance, it’s in the genetics.

Therefore, just cut the diet and lose weight will not work: even if at first the results will be happy, after some time there will inevitably come a plateau effect – the nightmare of all thinners, when the weight is permanently frozen in place, despite the diet and exercise. And here it is necessary to give an additional impetus to the metabolism, revising not so much the calorie content, but rather the quality components of the diet.

If we continue to simply reduce calories, the body will go into a mode of austerity, freezing many functions until better times, which can lead to a lot of negative consequences – from chronic fatigue and weakened immunity to fatal hormonal failure.

Does it even make sense to count calories?

As a general, very approximate system of coordinates, the indicator of calories is working at best. The rule of “eating less and moving more means you lose weight.

But there is a lot of nuances. Once again, let me remind you that the underlying all of today’s calorie labeling of foods Atwater’s system was developed almost a century and a half ago. But in that time, much of our knowledge of the world has moved on. For example, in Atwater’s time, science knew nothing about vitamins, dietary fiber, beneficial minerals, and other micronutrients-that is, that our weight and well-being are affected not only by the quantity but also by the quality of food.

Since then, humanity has consumed far more “empty calories,” that is, refined sugar, oil, and flour. This, of course, could not have been anticipated by Atwater. Today, many scientists believe that in order to maintain and adjust weight, it is not so much important to know the calories, but rather the glycemic index of a product, which means the rate at which it increases blood glucose levels. Refined foods, which are rapidly processed and absorbed into the bloodstream almost immediately, have a much higher glycemic index than the same foods in their natural state. For example, the glycemic index of refined white rice is almost 1.5 times higher than that of brown rice, which has preserved the shell of the grain, while the number of calories in them is approximately the same.

There is another pitfall in the well-established counting system, which is called the “Atwater trap” in nutritional parlance. Counting does not take into account the physical condition and consistency of the food. It is now proven that soft and thermally processed foods are processed faster and more completely than raw and those that require jaw work to eat. This means that in reality, more energy comes with it than is stated on the label. Let it be a 10-20% fork, but over time you get some pretty weighty numbers. Japanese scientists did a very interesting study, though not on people, but on rats. They kept 20 rats on food of different consistency: half of them were fed hard pellets that they had to chew, while the other half were fed a mushy food containing exactly the same substances and number of calories. After 22 weeks, the rats in the soft-fed group weighed about 6 percent more than their congeners and had 30 percent more body fat than the control group, indicating Stage 2 obesity.

Simply put, you have to ask yourself not only “How many calories am I getting?” but also “From what source?” 300 kcal in bran is not the same as 300 kcal in fine refined flour muffins. And avocado fats cannot be qualitatively equated with fats from smoked lard, although in absolute calorie values they would be equal.

And finally, the most fundamental puncture. There is now proven evidence that different components require different amounts of calories to digest. Fat is digested the fastest, followed by carbohydrates, and protein the worst. The higher the proportion of protein in food, the higher the energy required to digest it. Studies in recent years have shown that people who ate a lot of fat had the same weight gain as those who ate almost five times as many calories, but in the form of carbohydrates. So, losing weight by replacing candy with nuts is not a good idea. Although this is not a reason to cut out, for example, butter or nuts: a lack of fats, especially in periods of hormonal growth and decline, that is, during growing up, and vice versa, in later life has a negative impact not only on appearance, but also causes cognitive impairment, even retardation or premature senile dementia.

Then wouldn’t it be easier to burn off excess calories at the gym instead of restricting your food?

Judge for yourself: half an hour of intensive running on the track burns 300 kcal, an hour of Tennis is about 700 kcal, an hour of fast cycling we lose 600 kcal, climbing the stairs to the 5th floor – 400 kcal. How is that possible? You sweated for half an hour on the treadmill, and “worked off” no more than half of yesterday’s eclair? It’s a shame, really. But we, in the process of evolution, are extremely energy-efficient structures. To sustain life, humans need 20 times less energy relative to their own body weight than the same rat. After all, in ancient times, man was not brought food on a plate, he had to run around to find in the wild the same modest, as it seems to us now, 300 kcal. The urge to conserve energy is our genetics. All the latest research proves that physical activity can help solve a lot of problems: build body definition, build muscle mass, keep blood vessels and heart healthy, but, alas, it is disastrously ineffective for weight loss per se. If you have a specific goal – to lose weight, then training alone, without a properly structured diet, will not work.

By the way, do you know what is the most energy-consuming organ in our body? It is not the biceps, but the brain, which eats from 200 kcal (in sleep) to 1000 kcal a day (in a state of strong tension: for example, during examinations). So the expression “lose weight on stress” is not a figure of speech at all, but a scientifically proven fact. But it is impossible to call this way healthy, once the situation is normalized, the body will quickly regain the expended fat reserves.

What can be the consequences of the fact that the concept of good nutrition is increasingly reduced to a formal counting of calories?

In this respect, one of the most unhealthy trends of recent times is the appearance of so-called “low-calorie” products, from which calories have been artificially removed: “zero-calorie” cottage cheeses, fat-free pastry creams, light versions of cheese or buttery spreads. In fact, these products are deceptive, because together with fats from them removed and fat-soluble vitamins, from them will not be absorbed calcium and proteins, which are linked with fats, and many other valuable things. Besides, it is known that fat is the main conductor of taste, so in order to imitate it, we have to add substitutes for everything: taste, density and smell.

But most importantly, such neutered foods don’t give us a sense of satiety. In response, we either increase portions, or force our body to work in a mode of constant stress and lack of vital elements, thus again sending it into a blind defense. Therefore, those who want to lose weight should first learn an axiom: you can effectively lose weight only on highly nutritious natural food, which properly makes the metabolism work and normalizes lipid metabolism.

Are there foods with “negative calories”?

This is a myth that contradicts the laws of physics. After all, how do you usually define “negative calories”? When it takes more energy to digest a product than it brings to the body, that is, we eat and still lose weight. Most often this property is attributed to various fiber-rich fruits and vegetables like grapefruit, salad leaves, spinach, celery, and others. But we know that the body spends no more than 20-30% of the energy it receives on digestion, and the remaining calories stay with us anyway. Another thing is that plant fibers really blunt hunger, and more energy is spent on their processing than, for example, on refined foods, which is why fiber is so important for lean people. But if you want to be not only thin, but also healthy, the main thing is to create not a calorie deficit, but a balanced diet.