Rethinking Obesity: Why BMI Alone Is No Longer Enough
For decades, BMI (Body Mass Index) has been the go-to metric for assessing weight and health risks.But according to leading obesity expert Liesbeth van Rossum, this approach is outdated. “The BMI is outdated as a single measure,” she asserts. “We need to take into account factors such as waist size and fat distribution. In addition, it is very important that we take into account the differences between men and women and ethnicities, such as the difference in fat distribution and how sick the fat is.”
This sentiment is echoed by an international committee of 58 experts, who recently published their findings in The Lancet Diabetes & Endocrinology. Their conclusion? Relying solely on BMI for diagnosis is insufficient. The new guidelines emphasize a more holistic approach, marking a significant step forward in global obesity healthcare.
The Shift Toward Comprehensive Assessment
Van Rossum, who chairs the new guideline on overweight and obesity in adults, highlights the importance of distinguishing between clinical obesity and preclinical obesity. “In clinical obesity, ther are signs that indicate organs that no longer function properly, such as increased blood pressure or diabetes, and/or difficulty with daily activities due to obesity,” she explains.
Under the new criteria,individuals with clinical obesity should receive immediate treatment—even if their BMI is below 30. on the other hand, those with preclinical obesity, where organs still function well, are encouraged to take preventative measures to avoid progressing to clinical obesity.
Preventing Over- and Underdiagnosis
One of the key changes is the inclusion of factors like waist size, fat distribution, and mental and physical health in diagnosing obesity. For women, a waist circumference of 88 centimeters or more indicates obesity, while for men, the threshold is 102 centimeters.
“This prevents over- and under-diagnosis,” Van Rossum explains. “At first, a woman with a BMI of 27 could think: ‘It’s not too bad, it’s just overweight and not obesity.’ While she may have a waist circumference of more than 88 centimeters, or, for example, a lot of fat around her organs, and could thus be obese.”
The new criteria also address overdiagnosis. “A bodybuilder with a BMI above 30 had to be treated for obesity according to the old criteria without having the disease. With the new criteria, we prevent someone with a higher BMI, for example due to a lot of muscle mass, from promptly receiving obesity treatment.”
Beyond BMI: A Broader Perspective
The limitations of BMI extend beyond weight classification. As Van Heun notes, “The impact of BMI also goes beyond just determining a ‘healthy weight.’ It is also used as a predictor of diseases such as cardiovascular disease and diabetes, while it does not take into account important factors such as fat distribution or muscle mass. That’s why it’s so important that we look beyond just the number when assessing someone’s health.”
Van Rossum is optimistic about the changes. “by preventing under- and over-diagnosis, we can also prevent other diseases that cause obesity—and, if thay are present, treat them better. It is a step in the right direction,especially if it is increasingly applied in practice.”
Key Takeaways
| Aspect | Old Criteria | New Criteria |
|————————–|————————————–|————————————–|
| Focus | BMI alone | Waist size, fat distribution, health |
| Clinical Obesity | BMI ≥ 30 | Organ dysfunction, nonetheless of BMI |
| Preclinical Obesity | Not addressed | Preventative care emphasized |
| Overdiagnosis | Bodybuilders classified as obese | Muscle mass considered |
The shift toward a more nuanced understanding of obesity is a game-changer. By moving beyond BMI, healthcare professionals can provide more accurate diagnoses and tailored treatments, ultimately improving patient outcomes worldwide.For more insights into the growing obesity crisis, read Never before has there been so much obesity in the Netherlands: ‘It is a gateway disease to more than 200 other diseases’.
