A prominent dietitian has issued a warning against placing too much faith in a single, widely-used health metric, arguing it can paint a misleading picture of an individual's overall wellbeing.
The Limits of a Popular Metric
Evan Lynch, a registered dietitian and the director of Nutrition in Europe for global nutrition brand AG1, stressed that while useful, Body Mass Index (BMI) should never be the sole measure used to evaluate health. He explained that BMI is a standard tool in healthcare for gauging adiposity, or body fat, and is central to screening for obesity risk and malnutrition. It is also used to determine eligibility for certain medications and procedures.
However, Mr Lynch pointed out significant drawbacks. "It is true that BMI is not perfect," he said. "It doesn’t account for muscle mass and can be manipulated easily by fluid retention or glycogen levels." He emphasised that as a standalone measure, it cannot depict trends over time and, crucially, cannot assess visceral fat – the dangerous fat stored around internal organs.
Why Annual Check-Ups Are Non-Negotiable
To build a complete clinical picture, Lynch strongly advocates for regular, comprehensive health assessments. He recommends that everyone gets their blood pressure and blood work done "at least annually." Alongside this, he suggests periodically tracking both weight and BMI.
"I would encourage people to keep track of their weight & BMI, not too often, but periodically," he advised. The NHS website provides a free online tool for calculating BMI, which indicates increased risk for conditions like heart disease and type 2 diabetes at higher readings.
Building a Complete Health Picture
Mr Lynch used a vivid analogy to drive his point home: "Relying on BMI alone is like trying to read a book by only looking at just one page: it may be informative, but it is far from complete." He acknowledged that while more precise tools like DEXA scans are ideal, BMI serves as a pragmatic and quick proxy for most of the population.
For those seeking more personalised insights, he recommends investing in a Bioelectrical Impedance Analysis (BIA) scale and conducting regular waist circumference measurements. These methods can offer a better understanding of individual body composition than BMI alone.
In conclusion, the expert's message is clear: "Every individual is different." While monitoring BMI has value, it must be part of a broader strategy that includes consistent, professional health check-ups to ensure an accurate and complete depiction of one's health.
