FEATURE ARTICLE By Aesha Tahir
ToneAndStrengthen.com
METABOLISM — THE KEY TO PACE OF LIFE Learning more about it can help us better understand our clients’ daily energy expenditure | By Aesha Tahir “Metabolism” has become quite the buzzword in fitness and nutrition circles. As a nutrition coach, my clients ask me about metabolism and its relationship to weight loss. A higher metabolic rate is equivalent to weight loss for many people. But is metabolism just that? What if metabolism is responsible for much more than our body weight? It sets the internal pace of life when we are at rest. It determines our capacity for essential body functions, growth and reproductive fitness. In a nutshell, it defines our odds of survival. Let’s take a deep dive into metabolism.
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What Is Metabolism? Metabolism is the sum of all chemical processes that transform one form of energy into another. As living things, we need continuous energy for our existence. Life as we know it exists because of the metabolic processes that obtain energy from the environment and provide it to support life. Metabolism breaks down food into energy our body needs for necessary functions like breathing, blood circulation, normal hormone levels and repairing cells. Even at rest, our body needs a minimum amount of energy to execute these functions and maintain a stable
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internal environment called homeostasis. There are three main components of metabolism. 1. Basal Metabolic Rate (BMR) —This is the amount of energy our body needs to keep functioning at rest. It includes performing essential functions to sustain life. BMR is the most significant portion of energy expended daily. 2. Dietary Thermogenesis — Thermogenesis means heat production. All metabolic processes in living organisms produce heat. Eating food produces heat in our bodies because of the energy required for digestion, absorption and storage of nutrients. Research suggests that 5%–10% of our total energy expenditure is due to dietary thermogenesis. 3. Daily Physical Activity – Structured exercise like running, swimming and a Zumba class requires us to use energy. Exercise, especially resistance exercise, also helps build muscle mass, requiring more energy. Don’t underestimate the effect of daily activities like gardening, home chores and walking around the house or office for energy expenditure. The non-structured exercise plays a huge role in our metabolism. Metabolism and Rate of Living Theory Metabolism defines our body’s capacity for vital maintenance, growth and reproduction — all these factors are related to our fitness as a living organism down to the cellular level. That’s why metabolism reflects “the pace of life.” The metabolic rate of a living being can determine its lifespan based on the “rateof-living” theory, which suggests that faster metabolism accelerates the aging process and slower metabolism slows down aging. Researchers have found that the slow metabolism of humans is responsible for the slow growth and long lives of our species. We might not appreciate it much but burning less than 50% of our daily energy intake is the main reason for our longevity. Take the example of your pet hamster, cat or dog. Their lifecycles are much shorter than humans because they approach adulthood much faster than us. A fast metabolism allows these animals to grow more quickly, reproduce more often and unfortunately have a shorter life span.