WHAT IS METABOLISM AND HOW IT HELPS IN FAT LOSS [SCIENCE EXPLAINED]

The words “slow metabolism” are incredibly overused. As in “I just can’t lose weight anymore, my metabolism has really slowed down.” Or “I’m not like you, I can’t just eat everything I want. Your metabolism’s faster than mine.”

Before blaming weight-loss failures on metabolic rates, let’s take a comprehensive look at how metabolic rates differ between people, what makes up your metabolic rate, and how all that changes when dieting or exercising.

To understand metabolism, you have to understand just a few basic terms. The energy your body burns in a day is called your total daily energy expenditure (TDEE), which has four components: resting metabolic rate, thermic effect of food, and exercise activity thermogenesis, and non-exercise activity thermogenesis.


What Does it Actually Mean by Metabolism?

Technically, “Metabolism” is the sum of all the chemical processes that keep your body alive.

In general terms, Metabolism defines as the use of energy for our day-to-day life.

The chemical processes in plants or animals change food into energy and help them grow.

actual meaning of metabolism
Me trying to explain about metabolism

They are further categorized as:-

Catabolism is defined as the process of breaking down in the body including digestion, absorption, etc.

Anabolism is just the opposite of catabolism, which simply means building up all the processes in the human body. Including building muscle, growing, etc.

A combination of these two processes, anabolism and catabolism is combined known as metabolism. These two processes keep going simultaneously in the human body.

Most people think of “metabolism” as the energy burned from the resting metabolic rate (RMR), which is the energy your body uses to stay alive, accounting for about about 70% of the Total Daily Energy Expenditure of sedentary people.

For performing these two processes it uses energy, and For a simple understanding of your purpose, I will use the term metabolism as a synonym of energy expenditure.

Sum of all the chemical processes in the body is known as metabolism which includes anabolism and catabolism. But in fitness and in general terms metabolism is often used as a synonym of energy expenditure.


Factors on which our metabolism depends?

So now you know that metabolism is defined as the number of calories that a person/individual is using on daily basis to sustain the present body composition.

And Yes, metabolic rate (the number of calories burnt a day) does vary between people.

Because metabolism depends on a few numbers of factors which are also known as Total Daily Energy Expenditure or TDEE. It will be discussed in a minute.

Most of the time, it isn’t that much of a difference and isn’t causative of obesity, but differences between people do tend to exist.


1. What is Your Resting Metabolic Rate (RMR)

Resting Metabolic Rate as the name suggests, is the number of calories that your body needs in a rested state. Also known as BMR (basal metabolic rate).

Many people ask that, why our body needs energy when we are not doing anything? why?

The answer will be you are not doing anything but your body is doing everything.

what is your resting metabolic rate

Your body is maintaining many systems even when you are in sleep like your cardiovascular system, digestion system, Respiration, excretory system, your brain is also thinking even when you are in sleep(dreams).

The majority of our body functions, without our will (involuntary functions).

what is your resting metabolic rate
Calories are burning even when you are in sleep

You will be surprised to know that your Resting Metabolic Rate contributed to 50-70% of your total caloric expenditure, Yes the majority of the calories are used by the involuntary functions only.

There do exist people with a “fast metabolism” — a.k.a. high RMR — but their metabolic advantage isn’t as overwhelming as you’d think.


IMPORTANCE OF LEAN MASS

The resting metabolic rate also depends on several factors like weight. The more weight you carry the more numbers of calories your body needs.

For example, Person A is 10 kgs heavier(lean mass) than Person B.

So if we assume that 1kg of muscle mass(lean mass) will use 16 calories, then

16 calories*10kg =160 calories.

So according to the calculation Person, A will burn 160 extra calories than Person B.

importance of lean mass
Lean Mass is important!

Extending this into practical terms 160 calories is not a huge amount but if we can increase from every aspect it can make up to large (every little thing adds up).

One meta-analysis concluded that 96% of people stay within 200–300 kcal of the average RMR.

So If someone will not use it To give a sense of calories, is approximately equivalent to 2 tablespoons of peanut butter or half of a large slice of pizza can fill up their deficit and their hard sweat will be of no use.

Basal metabolic rate is defined as the number of calories that our body needs in a rested state to perform all the necessary body functions like cardiovascular system, respiration, etc. Persons like fast metabolism do exist, if a person is carrying more lean mass than the other, then the person will surely burn more calories at rested state. It may help if someone has good knowledge about the calories of food items.



2. EAT (Exercise Activity Thermogenesis)

As the name suggests, EAT or Exercise Activity thermogenesis is the number of calories used during physical activity and exercise.

This includes performing weight training in the gym, doing some sort of cardio like running, cycling, or walking.

Exercise Activity Thermogenesis can contribute up to 20% to the Total Daily Caloric Expenditure or TDEE.

Increasing metabolic rate or energy expenditure during exercise can also vary a lot.

EAT (Exercise Activity Thermogenesis)
Doing weight training and cardio at the same time

For example, Performing weight training can burn 1 calorie a minute. Performing it for 1 hour can burn up to 100 calories.

The same goes with walking, 1 minute of steady-state walk burns 3-4 calories a minute. Doing it for an hour will burn 180-240 calories(a lot).

Weight training can benefit in long run, for instance, it burns fewer calories compared to cardio and walking but in long run, it helps in building muscle(lean mass) and that will result in increased metabolism in a rested state.

And doing high-intensity cardio(running) only for 20 minutes will burn a lot of calories as well.

EAT (Exercise Activity Thermogenesis)
Use treadmill but not this way

Note: Excessive high-intensity cardio may be responsible for muscle mass loss in long run, should be used as a strategy, people use it as the fundamentals of fat loss.

So a combination of all on regular basis can burn a whole lot of calories like:-

Weight TrainingWalkingHigh-Intensity Cardio(Running)Total
Time 1 hour1 hour30 minutes2.5 hour
Calories100-120 250-300360700-800 calories

From the above table, you can conclude that performing all these activities can burn up to 700 extra calories a day.

Exercise will induce increases in metabolic rate or Total Daily Energy expenditure in all persons by the inherent nature of the physical movement. There is a lower degree of variance for basic, aerobic movements like walking or jogging. The low variance may not hold for high-intensity exercises.



3. NEAT(Non-Exercise Activity Thermogenesis) and Active Living

non-exercise activity thermogenesis or Activity energy expenditure (AEE) is the most variable aspect of the Total Daily Energy Expenditure, ranging from 15% in less active individuals to 40% in highly active individuals.

Physical activities outside exercise cover significant physical effort in subconscious acts of daily life, such as fidgeting, chewing, walking short distances, or maintaining one’s posture(standing).

NEAT or Non Exercise Activity Thermogenesis is considered as all the activities which you do outside the gym, it includes hopping, fidgeting, humming, shouting, standing, and lots of things on daily basis.

NEAT(Non-Exercise Activity Thermogenesis)
People increase their TDEE by shouting

A novel study investigated 11 Japanese men under living conditions, but in a metabolic chamber to measure caloric expenditure via heat.

They divided the activity levels of participants into 3 categories :

  • Low intensity days,
  • Moderate intensity, and
  • High intensity days

Researchers found that that the same persons whose maintenance calories were 2200kcal were increased to average +/-143 calories on Low-Intensity days.

And on Moderate and High-intensity days, energy expenditure can differ up to 500 calories.

Studies in respiratory chambers and in free-living environments suggest that On average accounts for 4–17% of the TDEE or about 100–300 kcal/day.

NEAT(Non-Exercise Activity Thermogenesis)
Some people increasing NEAT be like

It can be achieved with active living like:-

  • Taking stairs instead of the lift,
  • Walking when on a phone call instead of just sitting,
  • Not sitting in same place for too long
  • Indulging yourself in small household activities

(These activities don’t burn a lot of calories but as you know every little thing adds up.)

It contributes up to 10-15% in Total Daily Caloric Expenditure(TDEE) on average office-going individuals daily basis.

Non-exercise activity thermogenesis is considered as active living which includes all the small activities outside exercise which includes standing, short distance walking, shouting, writing, etc. Up to 10-15% of your energy burn comes from these activities/movements associated with living. Moderately active living may be sufficient to negate the inherent differences in metabolism for a good deal of persons.


4. Thermic Effect of Food

Now here comes the most interesting part, when there is the food I am the most excited person ever. I am sure you are also one of them.

Thermic Effect of Food is considered as the number of calories burned in the food you ingest will be used to digest, absorb, and metabolize the rest of the food, and some will end burned off as heat.

Thermic Effect of Food
People who were not able to understand TEF

In simpler words, when you consume a meal its also needs some amount of energy to digest, absorb and circulate throughout the body. So the number of calories used in these processes for that particular macronutrient is known as the thermic effect of food.

The overall process is known indifferently as the thermic effect of food (TEF), dietary-induced thermogenesis (DIT), or specific dynamic action (SDA). [Some more complex terms 🙂 ]

The energy required to digest each macronutrient (its TEF) can be expressed as a percentage of the energy provided by this macronutrient:

  • Fat provides 9 Calories per gram, and its TEF is 0–3%.
  • Carbohydrate provides 4 Calories per gram, and its TEF is 5–10%.
  • Protein provides 4 Calories per gram, and its TEF is 20–30%.
Boring Maths
1 gram fat= 9 calories
70 grams*9= 630 calories

3% of 630 calories= 19 calories

Starting off with fats, if a person is consuming 60-70 grams of dietary fats in a day, then the person is getting 630 calories from fat had if it’s TEF if 3% then the amount comes to 19 calories. So 19 calories are the number the person is burning during the process of digestion dietary fats only.

Protein is one of the most macronutrients among all, So you consume 150 grams of protein, which will give you 600 calories(150*4). According to the above calculation, 120-180 calories will be used to digest and absorb protein only. #Increased Metabolism

Thermic Effect of Food
Non-vegetarians after knowing that

Apart from its fast metabolism it helps you to increase the lean mass of your body and during eating it helps you to feel full(satiety).

The same goes for carbohydrates also, If someone is consuming 300 grams of carbs a day. A person must be getting 1200 calories(4*300) from carbs. For digesting carbohydrates almost that person will burn 100 calories.

On average Thermic Effect of Food represents about 10% of the caloric intake of healthy adults eating a standard mixed diet, but your actual number will depend on various factors, such as your lean body mass and the size and composition of your meal.

This is one of the reasons why increasing your protein intake can help you lose fat, in addition to preserving your muscle mass when you eat below maintenance.

The thermic effect of food is defined as the number of calories used during the process of digestion and absorption of food, more specifically macronutrients. Protein burns, by far, the most energy of any of the three macronutrients. For that reason, and because of its protective effect on muscle mass, protein plays a central role in many diet templates.


CONCLUSION

Sum of all the chemical processes in the body is known as metabolism which includes anabolism and catabolism. But in fitness and in general terms metabolism is often used as a synonym of energy expenditure.

Basal metabolic rate is defined as the number of calories that our body needs in a rested state to perform all the necessary body functions like cardiovascular system, respiration, etc. Persons like fast metabolism do exist, if a person is carrying more lean mass than the other, then the person will surely burn more calories at rested state. It may help if someone has good knowledge about the calories of food items.

Exercise will induce increases in metabolic rate or Total Daily Energy expenditure in all persons by the inherent nature of the physical movement. There is a lower degree of variance for basic, aerobic movements like walking or jogging. The low variance may not hold for high-intensity exercises.

Non-exercise activity thermogenesis is considered as active living which includes all the small activities outside exercise which includes standing, short distance walking, shouting, writing, etc. Up to 10-15% of your energy burn comes from these activities/movements associated with living. Moderately active living may be sufficient to negate the inherent differences in metabolism for a good deal of persons.

The thermic effect of food is defined as the number of calories used during the process of digestion and absorption of food, more specifically macronutrients. Protein burns, by far, the most energy of any of the three macronutrients. For that reason, and because of its protective effect on muscle mass, protein plays a central role in many diet templates.

3 thoughts on “WHAT IS METABOLISM AND HOW IT HELPS IN FAT LOSS [SCIENCE EXPLAINED]

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

Create your website with WordPress.com
Get started
%d bloggers like this: