Fitness trainer Viktor Mandzyak: We burn the most calories while at rest.

In an interview with RBK-Ukraine, fitness trainer and nutritionist Viktor Mandzyak discussed whether sports are essential for weight loss, which workouts are most effective, why Ozempic is not as harmful as it is often portrayed, how sleep affects weight, and whether calorie counting is necessary for losing weight.

Viktor Mandzyak is a well-known fitness trainer and nutritionist, the author of the largest weight loss project in Ukraine called "Science and Common Sense." He has also written three books on weight loss and a healthy lifestyle: "The Trainer Approves! 50 Myths About Weight Loss," "Stop Weighing Yourself, Measure Your Waist," and "Weight Loss Without Dancing with a Tambourine."

Read about proper nutrition planning, myths about metabolism, calorie counting, intuitive eating, calculating your ideal weight, the impact of sleep on weight loss, the necessity of sports in life, "problem" areas, Ozempic, teas and pills for weight loss, and a healthy lifestyle for children in Viktor Mandzyak's interview.

This is an abbreviated version of our conversation. You can find the full version on the RBK-Ukraine YouTube channel.

– Where should one start the weight loss process?

– Many advise gradually changing eating habits since weight loss is primarily about dietary behavior. However, I am not an advocate of this approach; I believe one should make drastic lifestyle changes right away.

A person continues a certain behavior if they see positive results. When we gradually change our eating habits, such changes may not yield results.

A person who wants to lose weight should do everything from the start to ensure their nutrition and physical activity create a calorie deficit. They will see the fat in their body decrease through measurements or weighing, which will motivate them to continue on this path of fitness and health.

Of course, when discussing physical exercise, we should apply the principle of gradualness: gradually increasing the intensity and volume of workouts.

But why won’t this be excessive stress? Because an adequate diet for weight loss does not involve any food restrictions or extreme asceticism. A person can lose weight while still enjoying their favorite, likely calorie-dense food, just in limited amounts.

When it comes to eating behavior, an important aspect is the number of meals per day. Most people eat chaotically; they eat reflexively.

– How can one calculate the necessary number of meals for themselves?

– It’s not that someone physiologically needs five meals a day while another requires only two. The question is how many meals are more comfortable for a person, considering their usual lifestyle. The essence is that a person should consume a certain number of calories.

This amount can be divided into five meals or two. For example, if I need to consume 2,000 calories, I can eat 500 calories four times a day. These will be small meals but relatively frequent. Or I can consume that food in two meals, with 1,000 calories for breakfast and dinner.

If I struggle with long periods of hunger, it’s better for me to eat smaller portions more frequently. But if I’m a busy person who doesn’t want to spend time looking for food each time, it’s better for me to eat until satisfied two or three times a day and be as productive as possible without being distracted by meals from my daily tasks. From both health and body composition perspectives, the number of meals doesn’t matter.

There is a common myth that fractional eating speeds up metabolism. This is nonsense. Metabolism refers to the biochemical processes in the body, which are only loosely connected to how we consume food. When we eat, metabolism increases due to the energy expenditure required for digestion and absorption of food.

– Is it necessary to count calories for weight loss? Can one rely solely on their own sense of fullness?

– There is a whole concept called intuitive eating. It suggests relying on your desire to eat, putting down your fork when you feel full, and asking yourself what you want to eat. However, it doesn’t work in the 21st century with the hyper-tasty, hyper-caloric food offered by the food industry.

Scientific data shows that such food leads to overeating, even if we consume it to a comfortable level of fullness. This is because a small amount of food can contain a massive number of calories.

The stomach aims to be filled with food, and to achieve this, one needs to consume about 700 grams of food. In that quantity, hyper-tasty food can contain more calories than a person needs in a day.

Regarding calorie counting, I believe that in the 21st century, especially for individuals prone to overweight (which is most people), it’s essential to have nutritional literacy. At the very least, they should know the calorie content of the foods they consume to make informed decisions. Is that cheeseburger so tasty that I can overlook that it contains a third of my daily calorie intake? Perhaps I will choose something less tasty but not as calorie-dense, packed with nutrients.

– Is it true that the stomach can stretch if one consistently overeats?

– The feeling of fullness depends on many different factors. One of them is the stomach stretching. There are receptors on the stomach walls that signal to the brain via the vagus nerve that we are full.

Older scientific data shows that if one consumes an excessive amount of food, eating until they can’t breathe, they can either stretch the stomach or reduce the sensitivity of these receptors.

Thus, it is indeed necessary to stop eating in a timely manner. There is a significant risk of overeating in one sitting, especially when the food is very tasty. It’s important to eat slowly and chew thoroughly.

– How can one calculate their normal weight where they will feel comfortable?

– Our health and body composition are not influenced by body weight alone. What difference does it make aesthetically how hard I press my feet against the floor in my bathroom? What matters is how much fat is in my body, where that fat is localized, how much muscle I have, and how developed it is.

If we take people who perform strength exercises and pass them through a body mass index calculation, we will see that for most people with an athletic build, BMI will indicate overweight. This is because they do not have excess fat; the problem is not in weight.

What matters is fat as tissue; if there is too much, it distorts the body shape. Adipose tissue is an endocrine organ that produces many signaling molecules affecting health, particularly increasing the risks of inflammatory processes, diabetes, atherosclerosis, and Alzheimer’s disease. When fat accumulates in the abdomen, it negatively impacts metabolic health, quality of life, and longevity.

In the scientific community, the term "normal weight obesity" has emerged. This is when the body mass is normal according to BMI, but considering that people do not move, it leads to muscle degradation and fat accumulation in the abdomen.

– In your posts, I read that you are not an advocate of mandatory breakfast. Please explain your opinion.

– Our health and body composition are influenced by what we eat and how much we eat. Scientific data shows that most people have suppressed appetite in the morning. People tend to want to eat the most at 8 PM. It’s quite strange, isn’t it, to force food into oneself when you have no appetite in the morning? Food should bring joy. It should be consumed when you genuinely want to eat.

Consuming food when you don’t want to leads to overeating. Our body is a powerful machine that has evolved over millions of years. We have many different systems that allow us to function without food for a whole 24 hours. We have plenty of energy reserves in the form of fat. This energy is sufficient for essentially 90 days of fasting. I do not recommend fasting for 90 days; I’m merely stating physiological facts.

Not having breakfast does not negatively impact mood, productivity, or cognitive function.

Although insulin sensitivity is slightly higher in the morning. In the morning, the body better stores consumed carbohydrates in the muscles with a lower insulin release because muscles are more sensitive to insulin. But this is a minor factor in the overall energy expenditure for digesting food, accounting for only 10% of total energy expenditure, which is not significant, and a 1% increase will have no practical impact.

So, breakfast is not bad, but I see no reason to force myself to eat breakfast because food should bring joy. There are no objective reasons to force oneself to eat breakfast, absolutely none.

– You mentioned that a calorie deficit is more important for weight loss. Is exercise merely a tool for shaping the body, if I may say so?

– Exercise involves muscle tension. Muscles consume calories when they contract, and this affects the energy balance. Physical activity slightly increases the number of calories burned