Every time we restart a weight-loss journey, we tend to set goals like “I must weigh XX kilograms.” But did you know? Compared to focusing solely on “weight,” your body fat percentage is actually a much more important metric to set as a goal.
This is because your body fat percentage largely determines your body shape. Only when your body fat percentage decreases, and the proportion of fat in your body is reduced, will your physique appear more balanced, curvy, and strong. That’s the real key to effective weight management.
Body Fat Percentage: A Standard for Both Appearance and Health
The human body contains mainly two types of fat: blood lipids and body fat.
Blood lipids refer to fat in the bloodstream. High blood lipid levels can lead to atherosclerosis, high blood pressure, coronary heart disease, and other conditions. “High blood lipids” is one of the common metabolic problems known as the “three highs.”
Body fat, on the other hand, is what we usually refer to as fat, including subcutaneous fat and visceral fat. Subcutaneous fat is stored under the skin; you can feel it by pinching your waist, arms, or thighs. Visceral fat is deeper, surrounding your internal organs in the abdominal cavity.
Body fat percentage measures the weight of fat as a proportion of your total body weight.
Normal body fat varies with age and sex. Generally, for men, a healthy body fat percentage is around 10%–20%, while for women it’s around 20%–30%.
Exceeding these ranges indicates excess fat, while lower percentages suggest insufficient fat. Both extremes first manifest visually—too much fat makes it hard to hide, too little fat may make your body look flat or unhealthy.
Some may ask: “Isn’t fat or slim judged by the scale? What does body fat percentage have to do with it?”
Here’s the science: fat is three times the volume of muscle for the same weight.
This means that two people of the same height and weight can look very different. The one with a higher body fat percentage will appear much bulkier because fat takes up more space. Think of it like this: which occupies more volume, one pound of cotton or one pound of iron? Fat is just like the cotton—it takes up more room.
Beyond Appearance: Why Excess Body Fat is Unhealthy
Ideally, energy intake and expenditure should be roughly balanced. When intake exceeds expenditure, the surplus energy is first stored as subcutaneous fat. Subcutaneous fat has minimal health impact, but once storage capacity is exceeded, excess energy turns into visceral fat.
Visceral fat accumulation visibly changes your body shape—you can feel it as a small belly. But more importantly, visceral fat is extremely harmful, acting as a hidden culprit behind many diseases.
So does this mean the lower your body fat, the better? Not necessarily.
Fat is an essential tissue with critical functions: keeping you warm in cold weather, reducing friction between tissues during movement, and providing energy during fasting.
Fat also secretes hormones that regulate metabolism. For most women, too low a body fat percentage can disrupt hormone balance and cause irregular menstruation.
In short, maintaining a healthy body fat percentage is all about balance. During weight loss, blindly pursuing extremely low body fat can have serious consequences. Don’t push yourself too hard.
How to Measure Body Fat Meaningfully
Now that you understand the importance of body fat percentage, how do you know yours?
Measuring body fat accurately can be tricky. The most precise methods involve MRI, dual-energy X-ray absorptiometry (DEXA), or hydrostatic weighing, but these are complex and expensive, not necessary for most people.
Body Fat Scales: Bioelectrical Impedance Method
The most common home method is a body fat scale, which uses bioelectrical impedance. Here’s how it works:
Muscle tissue contains more water and therefore conducts electricity better (lower resistance), while fat tissue has less water and higher resistance. By applying a small electrical current and measuring resistance, the scale estimates your body fat percentage.
Most body fat monitors have several contact points (electrodes) and provide gender-specific fat percentage references, making results easy to understand at home.
Waist-to-Hip Ratio: Measuring Visceral Fat
To assess visceral fat, a simple method is the waist-to-hip ratio (WHR).
WHR = Waist Circumference ÷ Hip Circumference
Studies show a strong correlation between WHR and visceral fat. In China, a WHR above 0.9 for men or 0.8 for women may indicate excess visceral fat. Every 0.1 increase in WHR raises early mortality risk by 34% for men and 23% for women.
Even simpler, just measuring waist circumference helps identify health risks. For Asian populations, a waist ≥ 80 cm for women or ≥ 90 cm for men indicates abdominal obesity, associated with multiple health problems.
Remember: no test is perfect. Absolute numbers matter less than relative changes over time. Regular measurement is key to motivating yourself toward a healthier lifestyle.
How to Achieve an Ideal Body Fat Percentage
For the general population, body fat percentage is an indicator of health. For fitness enthusiasts, it shows whether diet and exercise are effective. For those focusing on fat loss, it’s even more crucial.
So how do you reach an ideal body fat percentage? The answer is improving your lifestyle: eat scientifically and exercise consistently, ensuring energy expenditure exceeds intake.
Eat Smart: Adequate and Varied
Don’t starve yourself. Hunger reduces the body’s regulatory ability, causing dizziness, fatigue, and poor memory, and increases the risk of binge eating.
Eat low-fat, low-salt, high-protein foods. Adequate protein intake boosts metabolism. Good choices include chicken breast, beef, lean meat, seafood, eggs, dairy, and soy products.
Focus on foods with high satiety and low glycemic index (GI) to reduce hunger and avoid fat gain. Avoid excessive intake of:
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High-sugar foods (snacks, cookies, desserts)
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High-carb foods (bread, dumplings, refined rice)
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High-fat foods (fried chicken, burgers, barbecue)
Exercise: Find What You Enjoy, Increase Gradually
Start with familiar activities and gradually increase the amount. Don’t stress about exercising a set number of minutes to burn fat; consistency matters more than intensity.
Daily movement matters too. Brisk walking for 30 minutes a day improves health and supports fat loss.
For most people, achieving a good physique should always prioritize health first. Set realistic goals, find the right methods, and pursue healthy fat loss—that’s the proper way.