You may have a normal weight and still have a high body fat percentage. The scales tell you how much you weigh, but not how much of that is fat or muscle, or where the fat is distributed.
اضافة اعلان
A study has highlighted this gap. It found that about a quarter of men with a normal body mass index (BMI) in its sample had body fat above the threshold the researchers used to define excess fat.
However, this does not mean that a quarter of people of normal weight worldwide face a life-threatening risk, or that a slim appearance necessarily hides a health problem.
Beyond the weight figure
The study included 3,001 adults aged between 20 and 95. They underwent body composition tests and blood tests for heart and metabolic health indicators.
Of the participants, 967 were within the normal BMI range of 18.5 to 24.9.
In this group, 26% of men and 38% of women had high body fat, based on the study's definition: 25% or more for men, and 35% or more for women.
Higher body fat was linked to raised levels of some blood markers. In both sexes this included triglycerides, and in men it included total and "bad" LDL cholesterol.
The study is cross-sectional, meaning it records measurements at a single point in time. It does not prove that excess fat caused these changes, and it does not measure the likelihood of future death.
Not all body fat is the same
"Normal-weight obesity" describes a normal BMI combined with a high body fat percentage. Central obesity, by contrast, relates to how fat is distributed, particularly around the abdomen.
The two conditions can overlap, but they are not the same. A high body fat percentage alone also does not prove a loss of muscle strength.
For this reason, looking at weight or body shape alone is not enough to assess someone's health.
The mortality figure comes from a different study
In a separate study, researchers analysed data from 15,184 adults, with an average follow-up of about 14 years.
Central obesity, measured by the waist-to-hip ratio, was linked to a higher risk of death among people of normal weight.
The analysis estimated that a man with a BMI of 22 and central obesity had an 87% relative increase in mortality risk, compared with a man with the same BMI but without central obesity.
A tape measure alongside the scales
The UK's National Institute for Health and Care Excellence (NICE) recommends using the waist-to-height ratio alongside BMI to assess central obesity in adults with a BMI below 35.
To measure, place the tape halfway between the lower ribs and the top of the hip bones, take the reading after a normal breath out, and then divide the waist measurement by height, using the same unit.
The guidelines recommend keeping your waist measurement below half your height. However, this is a tool for estimating risk, not a stand-alone diagnosis.
The goal is to assess health more comprehensively, rather than relying on weight alone or trying to lose weight unnecessarily.
