A common condition of a diet is: “Egg, my metabolism is so slow, I never lose any weight.”
When people talk about fast or slow metabolism, what they are getting at is how many calories the body burns as they go about their day. The idea is that someone with a slow metabolism just doesn’t use the same amount of energy to perform the same action as someone with a fast metabolism.
But does the speed of metabolism change everything from person to person? I am a nutritionist who focuses on the biological, environmental and socioeconomic factors that influence body composition.
-This question is harder than it might first appear – and no matter how fast your metabolism is currently, there are things that will lead to lower or higher gears.
Your body needs energy
Metabolism is a biological term that refers to the chemical reactions needed to sustain life in an organism. Your metabolism performs three main functions: converting food into energy; breaking down food into its building blocks for protein, lipid, nuclear acid and some carbohydrates; and eliminate nitrogen waste.
If you’re leaning over the pace of your metabolism, you’re likely focusing on the energy you get from the foods you eat and what your body uses. The energy value of food is measured in calories.
Your caloric needs can be divided into two categories.
Basal metabolic rate is the minimum amount of calories needed for basic activities at rest. Resting on energy consumption is the amount of calories you use when you rest or sleep – about 60 percent – 65 percent of your total energy cost.
It doesn’t take into account the calories you need to power everything else you do – moving around, or active energy expenditure (25 percent – 30 percent), think , even digesting food (5 percent -10 percent). So your total energy expenditure combines two things: your resting energy expenditure and your energy costs for other activities.
Coming up with a number
The estimated daily caloric requirements for an adult female of 126 pounds (57 kg) range from 1,600 to 2,400 calories per day. For one of 154 pounds (70 kg), daily calorie requirements can range from about 2,000 to 3,000 calories per day. That’s about 13 calories per pound of body weight.
In comparison, babies burn about 50 calories per pound of weight each day. This requirement decreases continuously as the child ages. So babies have the highest metabolism. This extra calorie requirement is essential for growth.
So if two women of the same weight can have caloric needs that vary by as much as 30 percent, does that mean that the woman who consumes more calories has a faster metabolism than the woman whose body uses fewer calories? Not necessary. One woman may spend more of her day physically and therefore need more energy to power the walk and the after-work kick-off class, for example.
Beyond these rough guideline areas, there are many ways to estimate total rest and energy costs if you want to determine your body’s specific calorie needs.
One common and easy way is to use prediction formulas like the Mifflin-St. Jeor or Harris-Benedict equations are based on your age, height, weight and gender to determine what energy your body needs just to survive. To calculate total energy expenditure, you also need to add the activity factor.
Indirect calorimetry is another way to estimate metabolic rate. Energy expenditure is measured by measuring the amount of oxygen used, and carbon dioxide released by the body.
Your body depends on oxygen to perform all the functions of metabolism. For every liter of oxygen you consume, you use about 4.82 calories of energy from glycogen or fat. Indirect respiratory calorimetry is usually performed in a doctor’s office, although small, more affordable portable devices are being brought to market.
Factors affecting metabolic rate
Metabolic and calorie level requirements vary from person to person depending on factors such as genetics, gender, age, body shape and the amount of exercise you do.
Metabolism can be affected by certain health status and medical conditions. For example, the regulator of metabolism is the thyroid gland, located in front of the neck just below Adam’s apple. The more thyroxin a person produces in the thyroid gland, the higher that person’s basal metabolic rate will be.
Fever can also affect a person’s basal metabolic rate. For every 0.9 degrees Fahrenheit (0.5 C) increase in a person’s internal body temperature, their basal metabolic rate rises by about 7 percent.
Other medical conditions that affect basal metabolic rate can include muscle wasting (atrophy), prolonged hunger, low body oxygen levels (hypoxia), muscular disorders, depression and chronic illness. the sugar.
Another important feature is body composition. For example, an obese woman with a body composition of 40 percent body and 75 pounds (34 kg) of muscle mass burns fewer calories while resting than a woman with 30 percent body fat. and 110 pounds (50 kg) of muscle mass; muscle tension is more metabolically active than fat tissue in the body.
This is also the reason that basal metabolic rate decreases with age. As people get older, they usually lose muscle mass and gain fat tension – which equates to a decrease in basal metabolic rate of about 1 percent to 2 percent every decade. .
If you really want to jumpstart your metabolism, the easiest way is to push up your muscle mass and activity level. Increasing muscle mass will also increase the basic number of calories needed to maintain those muscles. Instead of complaining about a slow metabolism, you can try to turn it into at least a little faster. 
Terezie Tolar-Peterson, Associate Professor of Food Science, Nutrition & Health Promotion, Mississippi State University.
This article is republished from The Conversation under a Creative Commons license. Read the original article.