The traditional Body Mass Index (BMI), calculated as weight (kg) divided by height squared (m²), has been widely used to assess obesity and health risks. While it is simple and easy to use, it has notable flaws. One major issue is that it treats height in a two-dimensional manner, despite the fact that the human body is three-dimensional. This can lead to inaccuracies, as shorter individuals may appear thinner than they are, while taller individuals may seem heavier. The formula does not consider factors such as muscle density or body shape, which can result in misclassifications, especially for athletes or individuals with higher muscle mass.

Oxford University has proposed a new formula to address these shortcomings. Instead of using height squared in the calculation, it uses height raised to the power of 2.5, reflecting the non-linear scaling of body dimensions. The new formula is expressed as BMI = 1.3 * weight (kg) / height (m)².⁵. This aims to provide a more accurate assessment of body weight relative to height. The adjustment leads to small but significant differences, particularly for individuals at the extremes of height. Taller individuals typically see their BMI decrease, while shorter individuals may experience an increase. While this new approach could enhance our understanding of body health, it is important to note that no BMI formula can fully replace a comprehensive health assessment.