Basal and Active Metabolism

Written by

·

 

Order this tea to boost your metabolism! How many times have you seen such an advertisement on TV, radio, or the internet, where such promises seemed quite plausible? “I have excess weight because my metabolism is slow, even though I barely eat.” Or perhaps you know someone who eats everything and doesn’t gain weight because they have a “fast metabolism.”

But what is metabolism really, and how can we roughly calculate our metabolic rate expressed in kcal?

What is Metabolism?

Metabolism is a set of chemical reactions that occur in the body to maintain its normal functions. These reactions fall into two categories:

  • Anabolism: The synthesis of organic substances in the body, such as nucleic acids, enzymes, hormones, or cells.
  • Catabolism: The breakdown of organic substances, primarily under the influence of enzymes.

Both processes require energy, which we must provide through food. Metabolism is mainly associated with our diet, and energy production occurs in our cells’ mitochondria – often referred to as the body’s “energy factories.” The energy unit used in our body is ATP (adenosine triphosphate), primarily produced through the citric acid cycle (aerobic respiration).

In short, metabolism is a complex system of reactions that no single tea or shake can magically speed up.

Metabolism at Work

Most metabolic reactions happen without our awareness. Whether lying down, relaxing, watching TV, or scrolling Instagram, our body is constantly consuming energy. Tasks such as breathing, digesting food, heartbeat, and even thinking about vacations all require energy. Surprisingly, our body burns more energy during a day of doing nothing than during 60 minutes of jogging on a treadmill!

Even digesting food – for instance, a chocolate bar – requires energy. The catabolic part of metabolism breaks down the food, allowing nutrients to enter the bloodstream from the intestines.

Metabolism operates 24/7, mostly without our conscious input. However, there’s a part we can influence: the energy we consciously expend through daily activities. Together, these components define our total metabolism and how much energy our body needs.

Basal and Active Metabolism

Our total metabolism can be divided into two components:

  1. Basal Metabolism: All energy-consuming reactions occurring unconsciously (e.g., breathing, heart rate).
  2. Active Metabolism: Energy expended through conscious activities (e.g., walking, exercising).

To maintain a healthy weight or achieve specific goals, understanding these components is essential. Here’s how to estimate them:

Calculating Basal Metabolism

Use the following formulas:

  • Men: Basal Metabolism = 1.0 × normal body weight × 24 hours
  • Women: Basal Metabolism = 0.9 × normal body weight × 24 hours

Why the difference? Men generally have a higher percentage of muscle, which burns more energy than other tissues.

Example:

Let’s calculate for a 42-year-old woman weighing 70 kg, 163 cm tall, who works in an office. Her normal weight is:

Normal Weight = Height (163 cm) – 100 = 63 kg

We use 63 kg in the formula:

BM = 0.9 × 63 × 24 = 1360 kcal

Her body burns 1360 kcal daily for basic functions like breathing and digesting food. If she leads a sedentary lifestyle (office work, no post-work activity), we estimate her total metabolism by multiplying the basal metabolism by 1.2:

TM = 1360 × 1.2 = 1630 kcal

Key Takeaways:

  • To maintain her weight, she needs to consume around 1630 kcal daily.
  • Any changes in her weight would require adjustments in diet, activity level, or lifestyle

Boosting Metabolism: What’s Possible?

While we can’t significantly alter basal metabolism, certain factors can influence it, including:

  1. Muscle Mass: Building muscle increases energy expenditure as muscles consume more energy.
  2. Food Choices: Whole foods require more energy to digest than processed foods. For example, proteins are harder to break down, with only 75% of their calories absorbed compared to carbohydrates, which can reach up to 100% absorption.

Enhancing Active Metabolism

The active part of metabolism offers more opportunities for improvement:

  • Job Changes: Transitioning from a sedentary job to one requiring movement (e.g., teaching) can increase the activity multiplier from 1.2 to 1.5. For our example woman, this means an extra 400 kcal burned daily (enough for a dessert!).
  • Daily Physical Activity: Walking, cycling, or regular gym workouts can significantly raise total metabolism.

The Myth of Metabolism-Boosting Drinks

Unfortunately, there’s no magical tea, shake, or drink that will boost your metabolism. These products might empty your wallet, but they won’t deliver results. Instead, focus on both sides of the energy equation: diet and activity.

By understanding basal and active metabolism, you can make informed decisions about your lifestyle and health. Remember, real change comes from sustainable habits, not quick fixes!

2 responses to “Basal and Active Metabolism”

  1. My 30-Day Challenge – The Hungry Pharmacist Avatar

    […] Here’s how I calculated my daily needs: […]

    Like

  2. Insulin – is he really the Bad Guy? – The Hungry Pharmacist Avatar

    […] Surplus?Body weight is affected by the amount of energy we consume compared to the amount we burn. Basal metabolism takes the largest part of our energy throughout the day, so even if we do nothing all day, we’ll […]

    Like

Leave a comment