The core element of weight loss: body fat percentage and its importance.

**The core element of weight loss: body fat percentage**

Weight loss, as the name suggests, is about losing muscle, or what's commonly known as reducing fat. When we step on the scale, the number we get is actually the total weight of bones, muscles, organs, body fluids, and adipose tissue. Therefore, a scale cannot tell us whether our weight loss is due to water, muscle, or fat. If you want to know about changes in your body's tissues, you need to learn how to measure your body fat percentage. Managing your body starts with controlling your body fat percentage, correcting the misconception that weight loss is simply about reducing weight.

Why do we need to know our body fat percentage? Because body fat content has a very important impact on human health and lifespan. We've already learned that fat is mainly distributed in the subcutaneous tissue, omentum, mesentery, and around internal organs. It's not only a primary energy source for metabolism but also essential for human development and health. It's a major component of brain cells, and an appropriate amount of fat helps protect various brain functions, especially memory. Fat is necessary for the body to absorb and utilize vitamins, and it also acts as a "buffer" to protect internal organs, maintain normal body temperature, and keep hair and skin healthy, playing a vital role in our bodies.

Obesity is a root cause of chronic diseases. Whether it's traditional Chinese medicine, Western medicine, or health management professionals, they all warn us that reducing illness requires controlling weight. Obesity is caused by excess body fat, and controlling body fat percentage-one of the key issues discussed in this book-is crucial. Lowering body fat percentage reduces visceral fat, leaving more space for intestinal motility. Improved gastrointestinal motility helps increase the basal metabolic rate, aiding in the digestion and excretion of toxins and harmful substances, thus promoting overall health. Therefore, controlling body fat percentage leads to a naturally elegant figure, weight loss, and improved health.

So, what is body fat percentage? Body fat percentage is the percentage of body fat in a person's total body weight. Body fat can be calculated. Here's a formula: For women: Parameter a = Waist circumference (dm) × 0.74, Parameter b = [Weight (kg) × 0.082] + 34.89, Total body fat weight (kg) = ab, Body fat percentage = (Total body fat weight ÷ Body weight) × 100%. For men: Parameter a = Waist circumference (dm) × 0.74, Parameter b = [Weight (kg) × 0.082] + 44.74, Total body fat weight - kg = ab, Body fat percentage = (Total body fat weight ÷ Body weight) × 100%.

There are many methods for calculating and measuring body fat percentage, some of which are cumbersome, and others contain errors. Currently, body fat analyzers are popular among those trying to lose weight, as they are simple and easy to use. It's important to develop good habits for measurement. The best time to measure is generally in the morning, after waking up from a full night's sleep (7-8 hours). At this time, your weight and waist circumference measurements are relatively accurate. As we've already learned from the previous introduction, the components of body weight are: bones, muscles, water, and fat. ① Bones are formed at birth and cannot be changed later in life. Therefore, people with larger bones and higher bone density tend to weigh more than those with smaller bones and lower bone density. ② Muscles are the body's second heart. They are not only a symbol of health and strength but also an important factor in maintaining abundant energy and a good physical condition. Muscles are small in volume but high in mass, meaning they have high density and firm, elastic lines. Therefore, people with more muscle mass weigh more than those with less muscle mass. ③ Water is the component of the body that most easily causes changes in weight. Weight changes significantly before and after drinking water and before and after sweating. ④ The amount of fat is the true standard for determining whether a person is obese. Fat is the least dense component of the human body, characterized by its low density and large volume. It can be seen that the composition and changes in weight are complex, and simply using BMI to measure a person's weight is currently incomplete. Combining it with body fat percentage provides a more comprehensive understanding of a person's weight. Body fat percentage is the most direct and powerful data reflecting a person's degree of obesity, eliminating the influence of bone, muscle, and water on the weight number. Body fat percentage also differs between genders; the assessment standards for men and women are different. Women tend to have higher body fat percentages than men due to physiological reasons such as ovulation, childbirth, and breastfeeding. Body fat includes not only subcutaneous fat but also visceral fat. Therefore, not all men with a body fat percentage below 15% or women below 22% have a beautiful and toned physique; similarly, not all handsome men and beautiful women who appear slim in clothes have a body fat percentage within the normal range.

It is known that the ideal body fat percentage for a normal person is usually between 13% and 20% (for men). Michael Jordan's body fat percentage once reached 3.4%, which is considered the limit for basketball players. NBA Heat superstar Dwyane Wade also reached an astonishing 3.5%. LeBron James' body fat percentage was 6.7% when he was drafted, and it gradually decreased to 6% after entering the NBA.

In summary, our analysis and understanding of Body Mass Index (BMI) and body fat percentage are as follows: ① Low BMI + low body fat percentage = thin. This is generally caused by endocrine or digestive absorption disorders. Men with this condition often find it difficult to build muscle, while women are prone to menstrual irregularities. ② Low BMI + high body fat percentage = hidden obesity. This is generally caused by repeated dieting, lack of exercise, and low muscle mass. ③ High BMI + high body fat percentage = obesity. This is a high-risk group for various potential serious diseases. ④ A healthy and normal body is characterized by a BMI within a healthy range and a relatively low body fat percentage, resulting in toned and attractive physiques. For example, a young man who is 182 cm tall, weighs 73 kg, and has a body fat percentage of 13% can generally be considered to have relatively strong muscles and a well-built physique.

Therefore, to understand your obesity index and assess your weight loss progress, you must start with your body fat percentage. Only when your body fat percentage decreases can you consider weight loss effective. Body fat percentage can be measured at home using a body fat analyzer. The main principle is that the body's electrolytes have natural conductivity; blood and muscles contain electrolytes, while fat contains relatively less. In other words, the more muscle and the less fat in the body, the easier it is for an electric current to pass through. Conversely, for people with less muscle and more fat, it is more difficult for an electric current to pass through. Based on this principle, body composition can be assessed by measuring impedance values. Therefore, even two people with the exact same weight may have different body fat percentages. However, it's important to note that body fat percentage should be measured over a long period, ideally at a fixed time. For example, measure every morning after waking up, and every night before going to bed. Body fat percentage data can vary at different times, so measurements should be taken and compared consistently. If your body fat percentage has already dropped to the standard range, but you still want to have better muscle definition, strength training can make you more fit.