How To Lose Body Fat - The theory behind the science
How do you lose body fat? Here are some body fat loss basics...
Whether you need to lose 5, 10, 20, or 30 pounds or more-- you know the amount of weight you lose on a weekly basis should still conform to
healthy weight loss program
guidelines.
This means approximately 1 percent of body weight weekly.
Your total body weight is basically made up of two components-- lean body mass (LBM) and body fat. You know your real goal is not simply to drop body weight but to lose as much body fat as possible without losing too much of your precious lean body mass in the process.
We asked the question,
what is body fat anyway,
and now that we know that body fat is merely nothing more than just unused energy, let's consider the theory behind the science of how to lose body fat...
How To Lose Body Fat and... Thermodynamics?
Contrary to popular belief, the body doesn't really create energy. It is acquired in one form and converted to another.
When energy conversion from one form to another takes place, no energy is lost. The physical science that studies energy exchange is called Thermodynamics.
This is the branch of science that explores the tenet that energy can be neither created nor destroyed, and is referred to as the First Law of Thermodynamics.
The first law of thermodynamics dictates that body mass remains constant when caloric intake equals caloric expenditure. Therefore to achieve weight change, an energy imbalance needs to be created.
Simply stated, the formula for weight change can be expressed as:
Change in energy stores = energy intake - energy expenditure
As the science goes, to gain weight, you need to create an imbalance in the form of a surplus of calories. To lose body fat, you need to create an imbalance in the form of a caloric deficit.
Let's just focus on creating a caloric deficit-- and how to lose body fat...
How To Lose Body Fat - Two sides of the equation...
From the formula above, we note two variables-- energy intake and energy expenditure.
Indeed, we can think of energy as both something that is taken in, ingested, or consumed AND something that is released, expended, or 'burned'.
Both are represented as heat production and measured in calories.
One side of the equation-- energy intake, has to do with the foods we eat. The quantity and the composition of the foods we eat determine how much energy we provide our bodies with.
Before we look at the three fundamental ways body fat loss is made possible-- let's examine the other side of the equation and see what is generally meant whenever anyone talks about energy expenditure.
In biomechanics, energy represents the capacity to do work.
Mechanics is the study of motion and the science concerned with the effect of forces acting on objects. Biomechanics then, is simply the study of the application of mechanics to biological systems.
Work is referred to as mechanical energy and is the product of force times distance:
Work = Force x Distance
When we spend energy, we call it energy expenditure. Energy expenditure refers to energy expended per unit of time to produce power.
Power is expressed as Work per unit of time:
Power = Work / Time
A simple way to look at it is to understand that power is really just how fast work is done.
Believe it or not, from these two formulas, you can calculate the amount of work done and power generated from 3 sets of 8 reps of a squat exercise, for example.
...Or a whole workout for that matter.
Energy expenditure then, can actually be calculated. It's really nothing more than the amount of calories you burn through physical activity.
However, the amount of energy you expend during physical activity only represents about 15 to 30 percent of your total daily energy expenditure.
Another 10 to 15 percent comes from the thermic effect of feeding (TEF).
Also called diet-induced thermogenesis (DIT), this represents the amount of calories expended to digest, absorb, assimilate, and store the food you eat.
But the great majority of the total calories burned daily-- some 60 to 75 percent, comes from resting metabolic rate.
How To Lose Body Fat and... RMR, BMR, VO2, and DCR?
Resting Metabolic Rate (RMR) is essentially the minimum calories required to maintain the body's essential life function, at rest.
...It's the amount of calories your body burns if you did no activity at all.
Some sources use the term Basal Metabolic Rate (BMR). In fact, there are only some small differences and the terms are often used interchangeably.
The biggest distinction is in the protocol used to measure BMR and RMR.
In clinical settings, both RMR and BMR involve measuring an individual's oxygen consumption (VO2).
However, BMR entails much more stringent testing conditions.
RMR will measure VO2 three to four hours after a meal with no prior physical activity-- but BMR requires fasting for the 12 previous hours, no physical activity for several hours prior, and absolute rest for at least 30 minutes before measuring oxygen consumption.
BMR will always be less than RMR. Can you see why?
Fasting for 12 hours is intended to remove any increases in metabolism that can result from digestion, absorption, and storage of food.
In other words, BMR attempts to reduce the influence of the thermic effect of food (TEF) when measuring VO2.
However, the difference in values is fairly negligible.
In practical terms, certified personal trainers do not have the equipment and technicians to measure oxygen consumption.
We use various methods and formulas to estimate a client's metabolic rate and daily energy expenditure. Regardless of which formulas are used, they are all 'estimations' and therefore, subject to standard error of estimates.
Still, estimating your metabolic rate or body heat production and arriving at your total daily energy expenditure, is important because it gives you an indication of what we call your Daily Caloric Requirement (DCR) ...or how many calories you need to eat in order to maintain body weight.
So, to get back to how to lose body fat, the point where energy intake equals energy expenditure assumes an equilibrium. When the amount of calories you eat equals the amount of calories you burn, no weight is either gained or lost.
This point is also often referred to as 'maintenance level'.
The Theory of How To Lose Body Fat
At first glance, losing body fat does not appear all that complicated.
There are essentially only three fundamental ways to create an energy, or caloric deficit.
If you wanted to create a caloric deficit of say, 500 calories, you could either:
1. Lower your energy intake by eating 500 calories less than usual...
2. Increase energy expenditure by burning 500 calories more than usual...
3. Or through any combination of both-- for example eating 250 calories less and burning 250 calories more than usual.
Ideally then, to lose body fat you should always choose option 3.
It's almost always considered a more effective approach to combine both nutrition and exercise to realize your body fat loss goals.
Taking in less calories through food in concert with burning more calories through physical activity helps you benefit from the unique advantages of both.
But whether we eat less, move more, or combine both, how many calories does it take to lose a pound of body fat?
In other words, how much should we eat less or how much should we move more-- or both, to lose 1 pound?
While many people already know the answer to this question, few know how that number is actually derived. Fewer still, have ever 'seen' what fat looks like in the body. This is the subject of our next topic...
