Is losing weight really a matter of the difference between calories consumed and calories burned?

Is the concept true?calories in, calories out“? The short answer is yes, but in reality it is much more complicated.

From the moment food touches your tongue until it leaves your body, your digestive system And gut microbiome working to extract nutrients from it. Enzymes in the mouth, stomach, and small intestine break down food for absorption, and microbes in the large intestine digest leftovers.

Under “calories in, calories out” refers to the concept that weight change is determined by the balance between calories consumed and calories burned. This includes not only the number of calories you eat through your appetite and absorb through digestion, but also how well those ingested calories are burned through metabolism.

Recent research shows that a significant factor influencing variability appetite, digestion and metabolismare biologically active food residues known as bioactive substances. These bioactive substances play a key role in regulating the metabolic centers of the body: the appetite center in the brain – the hypothalamus, the digestive bioreactor in the intestines – the microbiome and the metabolic centers of cells – mitochondria.

I am a gastroenterologistwho has been studying the role of the gut microbiome in metabolic diseases for the past 20 years. I'll discuss how dietary bioactives help explain why some people may eat more and gain less, and offer several dietary tools to improve metabolism.

Thoughts on appetite and digestion

Research has shown that consuming whole foods still packaged in their original fibers And polyphenols — the cell walls and colorful compounds in plants that give them many of their beneficial properties — results in more calories being lost through stool compared to processed foods, which have been “digested” in factories into simple carbohydrates, refined fats and additives.

This is one way that non-calorie factors influence the “calories in, calories out” equation, which can be useful in a society where calorie intake often exceeds needs. By eating more whole foods and less processed foods, you'll simply be able to eat more because there are more unprocessed calories. will leave from the other end unused.

Fiber and polyphenols also help regulate appetite and calorie intake through the brain. Your microbiome turns these bioactive residues into metabolites—molecular byproducts of digestion—that naturally reduce appetite. These metabolites regulate the same gut hormones that first inspired popular weight loss drugs Wegovy, Ozempic and Mounjaro, controlling appetite through satiety center your brain – the hypothalamus.

Processed Products are devoid of these bioactive substances and additionally enriched salt, sugar, fat and additivesto be hyper-tastywhat makes you want them and there is more.

Mitochondrial masters at the center of the action

Fully calorie tracking also depends on how efficiently your body burns them to support movement, thinking, immunity and other functions – a process that largely controlled mitochondria.

In healthy people, mitochondria usually have a high throughput capacity and easily process calories to provide cellular functions. Mitochondria work in people with metabolic diseases not so goodwhich leads to increased appetite, decrease muscle mass and increase fat deposits.

They also have less of a mitochondria-rich type of fat called brown fat. Instead of storing calories, this fat burns them to produce heat. Less brown fat may explain why some obese people have body temperature is lowerthan those who are not obese, and why there has been an increase in decline average body temperature.

Healthy mitochondria burning more calories may also explain why some people may eat more. without gaining weight. But this raises the question: Why do some people have healthier mitochondria than others?

On mitochondrial health Ultimately, many factors come into play, including those typically associated with overall well-being: regular exercise, adequate sleep, stress management, and a healthy diet.

Who turned off the metabo lamps

New nutrition research is revealing the role that previously underestimated dietary factors play in mitochondrial health. In addition to the essential macronutrients – fats, proteins and carbohydrates – and micronutrients such as vitamins and minerals, other food residues are also key to metabolism, including fiber, polyphenols, bioactive fats And fermentation products.

Unlike western dietwhich often does not contain these bioactive substances, traditional diets such as Mediterranean And Okinawannuts, seeds, fruits, vegetables, whole grains and fermented foods are rich in these factors. Many bioactive substances pass undigested through the small intestine into the large intestine, where the microbiome turns them into activated metabolites. These metabolites are then absorbed, affecting the number of mitochondria in cells and their functioning.

At the most fundamental level of cell biology, metabolites are turned on and off molecular switches V your genes through a process called epigeneticswhich can affect both you and your offspring. When the metabolites are turned on, they revitalize the mitochondria responsible for speeding up your metabolism, effectively increasing the number of calories you consume.

Be careful with the gap in the microbiome

A healthy microbiome produces a full spectrum of beneficial metabolites that support calorie burning brown fat, muscular endurance and metabolic health. But not everyone has a microbiome capable of converting bioactive substances into active metabolites.

Long-term use processed foods low content bioactive substances and high salt content and additives may disrupt the microbiome's ability to produce metabolites needed for optimal mitochondrial health. Excessive use antibiotics, severe stress and lack physical activity may also negatively impact the microbiome and mitochondrial health.

This creates a double nutritional deficiency: a lack of healthy food and lack of microbes to transform its bioactive substances. As a result, well-studied dietary approaches, such as the Mediterranean diet, may be less effective in some people with a disrupted microbiome, which can lead to gastrointestinal problems. symptomssuch as diarrhea, and negatively impact metabolic health.

In such cases, nutritionists study the potential health benefits of various low carb dietswho can bypass the need in a healthy microbiome. While the increased protein content of these diets may reduce the microbiome produces beneficial metabolites; low carbohydrate content stimulates the body's production of ketones. One of the ketones, beta-hydroxybutyrate, may function similarly to a microbiome metabolite – butyrate – V regulation work of mitochondria.

New approaches that target the microbiome may also be useful for improving metabolic health: butyrate and other postbiotics to provide ready-made microbiome metabolites, personalized nutrition to tailor your diet to your microbiome, intermittent fasting to restore the microbiome, and in the future, live bacterial therapies may be used to restoring the health of the microbiome.

Products for converting fat into fuel

For most people, restoring the microbiome through traditional diets such as the Mediterranean diet remains biologically achievable, but it is not always practical due to issues such as time, cost and taste preferences. Ultimately, maintaining metabolic health comes down to something so deceptively simple. pillars of a healthy lifestylelike exercise, sleep, stress management and good nutrition.

However, some simple tips and tools can help make choosing a nutritious diet easier. Consuming fiber, polyphenols, unsaturated fats and enzymes will help you focus on foods that best support your microbiome and mitochondria with “leftovers”. Calculators and bioactive ingredient apps can also help guide food choices for appetite control, digestion and metabolism to help restore calorie balance.