Metabolism is the set of chemical reactions in the cells of the body to convert food into energy. Our body needs this energy for everything we do, from moving to thinking to growing.
There are specific proteins in the body that control chemical reactions in metabolism. Thousands of metabolic reactions co-occur, all of them regulated by the body so that our cells stay healthy and work well.
How does metabolism work?
After eating food, our digestive system uses enzymes to:
break down (break down) proteins into amino acids
convert fats into fatty acids
transform carbohydrates into simple sugars (for example, glucose)The body can use sugar, amino acids, and fatty acids as energy sources when it needs them. These compounds are absorbed into the blood, which transports them to the cells.
After they enter cells, other enzymes speed up or regulate the chemical reactions responsible for “metabolizing” these compounds. During these processes, the energy from these compounds can be released for use by the body or stored in tissues—Bodily, especially in the liver, muscles and body fat.
Metabolism is a kind of juggling in which two kinds of activities happen simultaneously:
building body tissues and energy stores (called anabolism)
breakdown of body tissues and energy stores to obtain more fuel for bodily functions (called catabolism)Anabolism, or constructive metabolism, is fundamentally about manufacturing and storing. It contributes to the growth of new cells, the maintenance of body tissues, and energy storage for later use. Small molecules transform into more significant, more complex carbohydrate, protein, and fat molecules in anabolism.
However, the research contains many other interesting details. For example, when babies are born, their metabolism replicates that of their mother. Then, about a month after birth, your metabolic rate begins to accelerate powerfully. When weight is taken into account, a one-year-old burns calories 50% faster than an adult. Childhood – not adolescence or early adulthood – is the time when human metabolism reaches its peak. After the initial acceleration, the metabolic rate drops 3% each year until age 20, stabilising. From then on, the metabolism remains stable until that magical (average) age of 60 and then declines at a rate of .07% each year indefinitely.
This surprised Herman Pontzer, lead author of the study and adjunct professor of Evolutionary Anthropology at Duke University. “I am in my early forties, so I was hoping to find some evidence to support my own experience that my metabolism is slowing down. This is how I feel. However, it is not really what is happening,” he points out.
So what is the actual cause of midlife weight gain?
Of course, that doesn’t mean the dreaded accumulation of midlife body fat is pure imagination, he cautions. (Research shows that the average adult in America gains between one and two pounds per year from early to mid-adulthood.) It simply means that other factors are involved in addition to metabolism. “Stress levels, schedules, hormone levels, and energy levels are different between the ages of 40 and 60 compared to the 20-somethings,” explains Pontzer, who is also the author of Burn, a new book. on the science of metabolism. “If you gain weight, it’s easy to say, ‘Oh, it’s because of my metabolism.’ It’s almost like a scapegoat. Now that we know it’s not about metabolism, we can pay attention to some of those other factors. “
Research has also shown that metabolism and weight are not always as direct a link as is believed. “It’s not about how many calories are burned, but determining if more are burned than consumed,” says Pontzer. “The fact that you have a fast metabolism does not mean that you can match your consumption with your energy expenditure.”
