Stepping on a scale can sometimes feel like getting a verdict that could affect your mood, for better or for worse. The problem is that weight alone can’t tell you what you’re losing or gaining. Two people can weigh the same and look completely different. You can drop weight while losing muscle. You can stay the same weight while getting leaner. That’s why body fat percentage is such a useful metric. It helps you separate “I weigh less” from “I’m healthier”.
But measuring body fat isn’t as straightforward as people think. Some methods are excellent, some are “good enough”, and some are… basically educated guesses.
Body fat percentage is the proportion of your body weight taken up by fat tissue. It’s helpful because it adds context that the scale can’t:
Health risk: Higher body fat, especially around the abdomen (visceral fat), is linked to cardiometabolic risk.1
Progress you can miss on the scales: If you’re training, increasing protein, or on weight loss medication, you might be losing fat while maintaining (or gaining) muscle. The scale might barely move, but your body composition could be changing.
Better goal-setting: “Lose fat while keeping muscle” is a different goal to “lose weight at any cost”.
Motivation and adherence: It’s often easier to stay consistent when you can see that your fat mass is trending down even if weekly weight fluctuates.
But it’s only useful if the measurement is reliable enough to show real trends.
There isn’t a single perfect body fat percentage. What’s considered healthy depends on sex, age, and overall health. But there are broadly accepted ranges that clinicians use as a guide.2
For men
11–22% is generally considered healthy3
Younger men tend to sit toward the lower end
Body fat naturally increases with age
For women
15–31% is generally considered healthy4
Women need a higher essential fat level for hormonal and reproductive health5
As with men, body fat tends to increase gradually with age
It’s also worth noting that where fat is stored matters, not just how much. Fat stored around the abdomen (often reflected by waist circumference) is more closely linked to metabolic risk than fat stored around the hips or thighs.1
During menopause, this pattern of fat storage often changes. As oestrogen levels decline, women tend to shift from storing fat predominantly around the hips and thighs to storing more around the waist. Even without significant weight gain, this redistribution towards the abdomen can increase cardiometabolic risk, which helps explain why rates of insulin resistance, type 2 diabetes, and cardiovascular disease rise after menopause.5
That’s why your doctor might look at body fat percentage alongside waist measurements, rather than in isolation. Most importantly, however, is that being slightly above or below a “range” doesn’t automatically mean poor health. Trends over time, symptoms, fitness, and blood markers matter just as much.
There are a few ways to measure your body fat.
DEXA (dual-energy X-ray absorptiometry) is widely used in research and clinical settings. It provides a detailed breakdown of fat mass, lean mass, and bone mineral content.6
Pros
Highly accurate and consistent
Gives regional data (e.g., trunk vs limbs)
Cons
Costs money, requires an appointment
Not something you’ll do weekly
Best for
A “baseline” measurement and occasional check-ins (e.g., every 3–6 months)
These methods estimate body composition through body density: BodPod uses air displacement; hydrostatic uses water displacement.6
Pros
Strong accuracy when performed properly
Cons
Availability is limited
Can be inconvenient and pricey
Best for
People who want accuracy but don’t have easy DEXA access
These are the stand-on, hold-the-handles machines you’ll see in some clinics and gyms.6
Pros
Quick and repeatable
Often better than consumer scales
Cons
Still influenced by hydration and timing
Different machines can give different results
Best for
Regular tracking, as long as you use the same machine under similar conditions
Most home “body composition” scales use bioelectrical impedance through your feet. They’re popular because they’re easy and feel precise, but that doesn’t necessarily mean they’re accurate.
A hospital-based study comparing three commercially available smart scales against DEXA found that weight was measured quite accurately, but body composition was not. Fat mass and lean mass could be off by several kilograms, and errors varied depending on weight, BMI, and body composition.7
What this means in real life
Your scale may tell you your body fat is 22.4% today and 21.7% next week. That doesn’t necessarily mean you “lost fat”.
The trend can still be useful, but only if you measure consistently and don’t obsess over tiny changes.
Use smart scales as a directional tool, not a diagnostic device.
If your goal is fat loss and health improvement, waist measurements can tell you a lot.
Pros
Cheap, easy, repeatable
Waist changes often reflect improvements in central fat
Cons
Not a direct body fat percentage measurement
Best for
Almost everyone. Pair it with weight and photos and you’ll get a clearer picture than a single “body fat %” number.
If you want your results to be meaningful, you have to make sure they’re reliable. Here’s how:
If you’re using a smart scale at home
Measure at the same time of day, ideally morning
Do it after the toilet, before food
Keep hydration and alcohol intake consistent the day before
Don’t compare numbers taken after heavy exercise, sauna use, or long flights
Focus on 4-8 week trends, not day-to-day changes
If you’re using a clinic device
Stick to the same provider and machine if possible
Repeat under similar conditions (time, hydration, recent training)
Use it as a periodic checkpoint (e.g., every 3–6 months)
And remember
If the number changes dramatically in a week, it’s more likely water and glycogen than fat tissue.
It depends on what you’re trying to do.
If you want the most accurate snapshot: DEXA
If you want regular tracking: a clinic machine (same device) + waist measurements
If you want something simple at home: smart scale + waist + progress photos, but treat the body fat % as an estimate
Body fat percentage is a useful metric because it tells you more about your journey than weight alone, especially if your goals include muscle maintenance, performance, or long-term metabolic health.
But not all measurement tools are equal. DEXA remains the most reliable reference point, clinic-grade devices can be great for tracking, and smart scales can help you spot trends, as long as you don’t treat them like medical tests.
Elffers TW, de Mutsert R, Lamb HJ, de Roos A, Willems van Dijk K, Rosendaal FR, et al. Body fat distribution, in particular visceral fat, is associated with cardiometabolic risk factors in obese women. PLoS One. 2017;12(9):e0185403.
Gallagher D, Heymsfield SB, Heo M, Jebb SA, Murgatroyd PR, Sakamoto Y. Healthy percentage body fat ranges: an approach for developing guidelines based on body mass index. Am J Clin Nutr. 2000;72(3):694–701.
Neudecker K. What is a healthy body fat percentage? Men’s Health. 2015. [accessed 10 Feb 2026] Available from: https://www.menshealth.com/uk/health/a754847/what-body-fat-percentage-should-i-be/
Buick K. Body fat percentage for women: what should yours look like? Women’s Health. 2018. [accessed 10 Feb 2026] Available from: https://www.womenshealthmag.com/uk/health/female-health/a708160/body-fat-percentage-women/
Freeman EW, Sammel MD, Lin H, Gracia CR. Obesity and reproductive hormone levels in the transition to menopause. Menopause. 2010;17(4):718–26.
Escamilla RF, Yamashiro K, Asuncion R, MacLean D, Thompson IS, McKeough M. Comparison of four quick and reliable methods of assessing body fat appropriate for clinical settings among young, middle-age, and older healthy male and female adults. J Phys Ther Sci. 2024;36(9):518–25.
Mondal H, Mondal S, Baidya C. Competency in home body fat monitoring by portable devices based on bioelectrical impedance analysis: A pilot study. J Educ Health Promot. 2019;8(1):223.
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