Did you know that you can be both skinny and fat at the same time?
This might be counter-intuitive, but it’s true. A client of mine weighed 55.5 kg (around 121 pounds) but had a 33.8 percent body fat. She was in her late 30s. If we use the American College of Sports Medicine (ASCM) body fat guidelines, her body fat was below average even if she was slim.
A 2008 study published in the Archives of Internal Medicine found that about one-fourth of U.S. adults with normal weight were at risk for heart problems. They had larger waists or potbellies which means they might have internal fat deposits surrounding their abdominal organs, regardless of their healthy weight.
Such people are usually called “skinny fat” people. The fancy medical term for them is “metabolically obese normal weight” (MONW) individuals. This phenomenon begs the question: if people with normal weight can have too much fat in their body, is body weight a good indicator of body fat?
Weight Loss vs. Fat Loss
We’re living in a world where body weight has become the main indicator of health and fitness. Take the Body Mass Index (BMI), for example. The weight-based formula to predict body fat is widely used. The World Health Organization (WHO) uses it as a method to classify underweight, overweight and obesity in adults internationally.
You can also see how popular the term “weight loss” is. Many people know their real problem lies in having too much fat. But they assume that body weight is a good indicator of body fat. So they set losing weight as their fitness goal. They believe if they lose weight, most of the weight they lose must be body fat.
However, if that widely shared assumption is true, how could there be people who are skinny fat? To complicate things further, a friend of mine, Yakov, was 106.6 kg (around 235 pounds) but his body fat was only around 13 percent. So, he was quite lean yet he was overweight. How could this happen?
The answer is: because body weight is not a good indicator of body fat.
First of all, your weight isn’t just fat. There are other elements that make up your weight such as muscle, bone, water and other tissues. The weight of all your body tissues excluding fat is called your lean body mass (LBM). Muscle and water are the largest elements of your LBM.
Another problem is that your weight can fluctuate on a daily basis depending on various factors besides fat gain. Among them are your hydration status, your food, your sodium intake, and even—in women—your menstrual cycle.
To illustrate just how widely your weight can vary, let’s look at twenty-four hours in “the life of the scale,” using my client Anastasia as an example:
6:30 a.m. Anastasia woke up and got on the scale. She weighed 60 kg (around 132 pounds) undressed, after emptying her bladder.
7:30 a.m. Anastasia stepped on the scale wearing her bathrobe, after eating breakfast and drinking two cups of coffee. Her weight was now 61 kg (about 135.5 pounds).
10:30 p.m. Anastasia stepped on the scale naked, before putting on her pajamas. She went out to dinner and had Chinese food and two glasses of wine. Her weight was now 62.6 kg (around 138 pounds)!
What do you think the odds are that Anastasia gained 2.6 kg (about 6 pounds) of body fat in a single day? Slim to none, right?
Yet many people, especially women, take scale weight to be the gospel truth. Seeing those numbers fluctuate on a daily basis really terrorizes my female clients. Worse yet, some women insist on stepping on the scale several times per day. Talk about making yourself crazy!
Thus, there is a difference between losing weight and losing fat. Sometimes, after a high-intensity workout, clients said to me, “What a great workout, I just lost 1 kg (about 2 pounds)!” Of course, they didn’t really lose 1 kg of fat. It’s impossible to lose 1 kg of fat with only one workout session. They just sweated out the equivalent of 1 kg of water.
Most people assume that weight loss is always a positive outcome, and weight gain negative. But what if most of the loss or gain came from muscle? When you lose lean muscle mass, you’ll also lose weight. But most of the weight you lose is not fat.
How Good is BMI?
Now that we know the difference between weight loss vs. fat loss, I would like to elaborate on that further by discussing the widely used weight-based measurement method to assess body fat and health in general, namely the Body Mass Index (BMI).
Since BMI also uses height, advocates of BMI say that it’s a better gauge of health than your weight alone. The truth is, BMI might be an acceptable screening tool for the general population, but for many people BMI is just as misleading as the scale weight. This is especially true for anyone who has more muscle tissue because BMI assumes most of the weight to be fat.
There are two formulas to calculate BMI, i.e. the metric BMI formula and the imperial BMI formula. Both of them actually have the same logic and will always produce the same result. The difference is simply because the former uses metric measurement system such as meters and kilograms, while the other uses an imperial measurement system such as pounds, feet, and inches.
The metric BMI formula is as follows:
BMI = weight (kg) ÷ [height (m)]²
The imperial BMI formula is as follows:
BMI = weight (lb) ÷ [height (in)]² x 703
Let’s see how they work. I’ll use my friend Yakov as an example. As we already know, he weighed 106.6 kg. His height was 1.8 meters. Using the metric BMI formula, his BMI was:
106.6 ÷ 1.8² = 106.6 ÷ 3.24 = 32.9 BMI
The result will be the same when we use the imperial formula even though we have to convert Yakov’s weight and height first to the imperial measurement system:
106.6 kilograms = 235 pounds
1.8 meters = 70.9 inches
235 ÷ 70.9² x 703 = 235 ÷ 5026.81 x 703 = 32.9 BMI
Thus, Yakov’s BMI was 32.9, but what does this number mean? If we want to know the meaning of this number, we need to use the BMI chart that classifies whether a person is underweight, overweight or obese. And according to the WHO’s BMI chart, Yakov was obese.
But of course, he was far from obese. As I’ve said above, his body fat was around 13 percent which was quite lean for a man. The problem with BMI is that it can’t differentiate between fat and muscle.
Let’s look at another example: Alexey, a friend of mine who is a bodybuilder. He weighed 91.17 kg and he was 1.72 meters tall. Let’s plug his stats into the BMI formula and see what we come up with:
91.17 ÷ 1.72² = 91.17 ÷ 2.96 = 30.80 BMI
Judging him according to his BMI of 30.80, his health was at risk and he needed to lose some fat. Obviously, that was not the case, since he rarely hit double-digit body fat.
There’s another dark side to BMI, as well. BMI can mistakenly mark a skinny fat person as healthy. According to the Centers for Disease Control (CDC) data, 21 percent people with normal or underweight BMI had excess body fat. This could be dangerous because a skinny fat body is an unhealthy body.
The kind of fat that is stored by a skinny-fat body is the visceral fat. Visceral fat is the fat that is transformed into cholesterol which circulates in the blood. “Bad” cholesterol or low-density lipoprotein could form plaque in your arteries that leads to heart disease. Too much visceral fat could also cause insulin resistance and diabetes.
What Should Your Fitness Goal Be?
Having a clear goal is the first step toward success. It could keep you focused and stay on track. But if you set the wrong goal, you’ll end up in the wrong destination.
Many people set weight loss as their goal. But we’ve known that there is a difference between losing weight and losing fat. If you’re focusing on losing weight instead of fat, much of the weight you lose could be comprised of lean body mass. You’ll end up with just a smaller version of your old self, but you don’t become any fitter. Or worse, you’ll become a skinny fat person.
Thus, if you have a body fat problem, losing weight should not be your main goal. Your main focus should be to lose fat. To be more precise, you should focus on your body composition, i.e. the proportion of muscle and fat in your body. Improve your body composition by losing fat (without losing muscle) and adding muscle.
Many women scared of adding muscle because they wrongly think that gaining muscle will make them look bulky. Ladies, don’t worry, you won’t get bulky from adding muscle because you have about one-sixteenth of the testosterone—the primary driving force behind muscle growth—of the average men.
Muscle actually makes your body look toned and chiseled, but muscle has more than aesthetic value. It’s a metabolically active tissue that requires a lot of energy to build and sustain. This means that the more muscle you have, the more calories you’ll burn at rest. Muscle also has various health benefits such as increasing your potential longevity.
We have a big problem with what our society perceives as the ideal body. Most people are so fixated only on the kilograms or pounds of body weight and the outward appearance of “thinness.” They’re not paying attention to health and body composition. These are the measures of success that count the most, so most of your goals should revolve around them.
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