Many people want to lose fat. They not only want a healthy body, but also an aesthetically pleasing body. Since you’re reading this article, you may be one of them.
The problem is what should you do? Where should you start? Fat loss appears to have many aspects. Moreover, there’s so much different information out there about how to lose fat. Not to mention the gimmicks, fakes, and frauds that are ready to take your money for nothing.
That’s why we wrote this article. This article discusses the fat loss fundamentals. If you understand the fat loss fundamentals, you won’t be easily confused and misled by the sea of (mis)information out there.
What Exactly Is Body Fat?
Body fat is one of the tissues in your body. The technical term for it is adipose tissue. There are two types of adipose tissue, i.e. White Adipose Tissue (WAT) and Brown Adipose Tissue (BAT). Most of your body fat is WAT; humans only have very little BAT.
The main function of fat is to store energy from food. The unit commonly used to measure food energy is the one used to measure heat energy, i.e. kilocalorie or Calorie (with an uppercase C). One kilocalorie is equal to 1000 calories (with a lowercase c).
In scientific literature, the distinction between kilocalories or Calories (with an uppercase C) and calories (with a lowercase c) is carried out strictly. In popular literature, though, people use “calorie” (with a lowercase c) to refer to what is actually a kilocalorie. This article uses the term “calorie” in the same sense as in popular literature.
One gram of pure fat contains 9 calories, so 1 pound (454 grams) of pure fat contains 4,086 calories. However, your fat cells do not only contain fat; they also contain a small amount of water and other elements. The widely accepted measure today is that 1 pound of body fat contains about 3,500 calories.
This capacity of fat to store energy is much greater than that of carbohydrates or protein. One gram of carbohydrate or protein contains only 4 calories. One pound of carbohydrate or protein contains only about 1,816 calories.
Besides its main function to store energy, fat also has other important functions. For instance, fat helps protect vital organs such as the heart and liver. Fat also insulates your body from cold temperatures. Fat also helps the production and regulation of various hormones in your body.
Fat Loss and Calorie Deficit
Your fat mass is determined by your fat cell number and size. Fat cell number and size can vary across individuals. However, your fat cell number is almost impossible to change.
A study by Kirsty Spalding et al. published in Nature in 2008 found that the number of fat cells stays constant in adulthood. Every year, about 10 percent of your fat cells die, but they are replaced by the same number of new ones.
Spalding also studied people who lost an average of 18 BMI points using bariatric surgery, a surgery that shrinks the stomach to limit how much you can eat or/and to reduce the absorption of nutrients. It turned out that two years after surgery, their fat cell number remained the same despite the drastic decrease in BMI. What had changed was the size of their fat cells.
Now, some promote killing fat cells as a way to lose fat, either by liposuction, cryolipolysis (freezing them to death), or consuming CLA (Conjugated Linoleic Acid) or resveratrol. But, what’s the point of killing your fat cells if they’ll be replaced by the same number of new ones? Not to mention they could be risky.
This means that the only option available for you to lose fat is to reduce the size of your fat cells. Your fat cells can release the fat they contain, which is then transported to various parts of your body to be oxidized for energy. This is the process known as “burning fat.”
However, your fat cells can also store new fat from the excess calories you consume. If you want to shrink the size of your fat cells, you need to burn more calories than you consume or you need to consume fewer calories than you burn. This is the most fundamental principle of fat loss.
So, losing fat boils down to creating a calorie deficit. There are two ways to create a calorie deficit, i.e. reducing your calorie intake or increasing your calorie expenditure. Instead of using only one of them, the optimal approach is to combine the two.
How to Reduce Your Calorie Intake
Let’s discuss first how to reduce your calorie intake. If you want to lose fat, you need to eat calories below your Total Daily Energy Expenditure (TDEE). TDEE or maintenance level is the number of calories you need and burn every day to maintain your body. This is exactly what a diet is for, i.e. to reduce your calorie intake below your TDEE―read our other article to learn how to calculate your TDEE.
For example, suppose you have a maintenance level of 2000 calories per day. And you want to lose fat by creating a calorie deficit of 20 percent, which is 20% x 2,000 = 400 calories per day. Thus, you need to consume 2000 – 400 = 1,600 calories per day. In 9 days, you’ll have created a deficit of 3,600 calories, which is equal to losing more than 1 pound of fat.
Now, different types of food have different characteristics, so they can have different effects with the same amount of calorie intake. For example, the thermic effect of protein is 20-35 percent, while the thermic effect of carbohydrates is 5-15 percent. The thermic effect of food is the caloric cost of digesting and processing the food.
So, eating 100 calories of protein and eating 100 calories of carbohydrates will produce different effects. When you eat 100 calories of protein, your body will use 20-35 of those calories to digest the food, leaving you with only 80-65 calories. When you eat 100 calories of carbs, your body will only use 5-15 of those calories to digest the food, leaving you with 95-85 calories.
Different foods also have different calorie densities. Calorie density is the number of calories per volume or weight of the food. Eating low-calorie-density food can make you lose fat without making yourself hungry and feeling miserable.
Thus, reducing your calorie intake isn’t just about reducing the quantity of your food. You need to pay attention to the composition of your food, including your macronutrient (carbs, proteins, and fats) split. You can even eat more food and still reducing your calorie intake if you eat low-calorie-density food.
Last but not least, your TDEE is not static. After dieting for a while, your metabolism may slow down and your weight may be lighter, so your TDEE may be smaller. If your TDEE drops to the same level as your calorie intake, you’ll no longer create a calorie deficit. In other words, you’ve hit a plateau. If this happens, you may need to adjust your diet.
How to Increase Your Calorie Expenditure
Now let’s discuss how to increase your calorie expenditure. In general, it’s by exercising. But, there are also other factors that influence your calorie expenditure. If you know these factors, you can optimize your calorie expenditure. Here are the factors that affect your calorie expenditure:
1. Basal Metabolic Rate (BMR)
Basal Metabolic Rate (BMR) is the number of calories you burn for essential bodily functions, such as respiration, digestion, circulation, cell creation, and so on. BMR is also commonly defined as the number of calories you burn at rest, meaning without doing anything.
BMR is the largest part―about 60-75 percent―of your TDEE. BMR can vary based on various factors, such as your body weight, size, age, and how much muscle is in your body. The latter is the reason why strength training is important for fat loss, because by building muscles, it could increase your BMR.
2. Your Body Weight
As aforementioned, your weight influences your BMR. But, the effect of body weight on your total energy expenditure goes beyond that. Moving a heavy body requires more calories than moving a light body. That’s why people who are overweight tend to lose fat easily at first, but as they get lighter, they find it harder to lose more fat.
3. Non-Exercise Activity Thermogenesis (NEAT)
Non-Exercise Activity Thermogenesis (NEAT), as the term suggests, is the number of calories you burn for daily activities outside of exercise, such as walking, shopping, housework, etc. You could optimize your daily activities to help increase your TDEE.
For example, when you go to another floor in a building, don’t use the elevator, but take the stairs. When you park your car, park it a bit far from your destination, so you have to walk a longer distance from your car. Even though it looks small, if you optimize your activities every day, it may help increase your total energy expenditure.
4. Excess Post-Exercise Oxygen Consumption (EPOC)
After performing a workout, your oxygen intake will stay elevated for some time. Since oxygen consumption requires energy, this means you continue to burn calories above your resting level after the workout is over. The technical term for this phenomenon is Excess Post-Exercise Oxygen Consumption (EPOC). Some call it the “afterburn effect.”
The duration and number of calories burned through EPOC can vary based on various factors, such as the duration and intensity of your workout, your training status, etc. For example, it’s been widely known that HIIT, because of its intensity, is more efficient at inducing EPOC than steady-state cardio.
5. Your Training
This is obvious because your training will be at the core of what you do to increase your energy expenditure. The number of calories you burn with your training depends on the duration, intensity, and type of training.
Different types of training could also have different post-exercise caloric effects. Cardio, for example, may burn more fat than weight training during the workout session itself, but weight training may have a greater afterburn effect and could increase your BMR in the long run.
When creating a workout routine, you want a routine that is not only optimal for fat loss but also suitable for your conditions, such as your schedule, lifestyle, physical conditions, etc. You’ll also need to change your workout routine if you hit a plateau.
This article doesn’t go into many details. It’s simply impossible to go into all the details of fat loss in one article. After all, the purpose of this article is to provide you with the fat loss fundamentals.
At the beginning of this article, we’ve mentioned the benefit of knowing the fat loss fundamentals, that is, so you won’t be easily swayed and misled by the sheer amount of (mis)information out there. Another benefit we haven’t mentioned is that it allows you to create your own customized fat loss plan.
If you’re serious about losing fat, you should apply what you know in a planned manner. A plan provides direction and focus, so you won’t wander off course in your fat loss journey. A plan can also make you more efficient and effective. A good fat loss plan should include a goal, a way to track your progress, a meal plan, and a workout plan.
However, a good fat loss program should also be moderate and simple enough for people to follow in the long run. Fat loss is a slow and long process, so you need to have a long-term mindset. Even when you’ve reached your fat loss goal, you still have to adopt a new healthy lifestyle to maintain your weight and keep the fat off.