New research indicates that being underweight may pose a greater mortality risk than being overweight, challenging traditional views on body mass index (BMI) and health.
A significant new study from Aarhus University Hospital in Denmark has revealed that individuals who are underweight face a higher risk of death compared to those who are overweight or moderately obese. The research, which followed over 85,000 adults, suggests that the long-held assumptions surrounding body mass index (BMI) and health may need reevaluation.
According to the findings, people categorized as underweight were nearly three times more likely to die during the study period than those at the upper end of the normal BMI range. Even participants within the “healthy” BMI range but on the lower end exhibited an increased risk of early mortality.
In contrast, those who were overweight or moderately obese did not show higher death rates when compared to individuals with BMIs in the upper-normal range. This challenges the traditional view that excess weight is inherently dangerous, suggesting that being “fat but fit” may be a more accurate reflection of health than previously thought.
The researchers presented their findings at the annual meeting of the European Association for the Study of Diabetes (EASD) held in Vienna last week. The study highlights the importance of body fat distribution and underlying health conditions in determining overall health outcomes.
Dr. Sigrid Bjerge Gribsholt, the lead researcher, emphasized that both underweight and obesity represent significant global health challenges. Obesity is known to disrupt metabolic processes, weaken the immune system, and increase the risk of various diseases, including Type 2 diabetes, cardiovascular diseases, and several types of cancer. Conversely, being underweight is often associated with malnutrition, weakened immunity, and nutrient deficiencies.
Jens Meldgaard Bruun, another researcher involved in the study, pointed out that visceral fat—fat stored deep within the abdomen—can have detrimental effects on metabolic health. He explained that individuals with the same BMI can have vastly different health outcomes based on where their body fat is distributed. For instance, someone with a BMI of 35 who carries excess fat around their abdomen may be at risk for conditions like Type 2 diabetes or high blood pressure, while another person with the same BMI but with fat distributed around their hips and thighs may be healthier.
Bruun noted that treatment for obesity should be personalized, taking into account these factors and other health conditions when determining target weight. This approach could lead to more effective management of obesity and its associated health risks.
Dr. Akshaya Srikanth Bhagavathula, an epidemiologist at North Dakota State University who was not involved in the research, commented on the implications of the findings. He stated that they support other recent studies while challenging existing medical guidelines that assume health risks increase steadily with BMI. Bhagavathula explained that higher death rates in individuals with lower BMIs may stem from underlying illnesses that cause weight loss, making low weight appear more dangerous than it truly is.
He added that obesity often precedes serious health issues, according to the World Health Organization. In older adults, age-related muscle loss can increase vulnerability to falls and infections, while mild excess weight may provide a protective effect by serving as an energy reserve during illness. The healthy and active lifestyle in Denmark, characterized by widespread cycling, may also contribute to this protective effect.
Bhagavathula emphasized the need to consider BMI alongside other health measures, such as waist-to-height ratios, muscle mass, cholesterol levels, and blood sugar levels, as well as factors like sex and ethnicity. He argued that current health messaging often places excessive focus on weight loss, leading to shame and unnecessary medical interventions for individuals who are overweight but maintain normal bodily functions.
In light of these findings, Bhagavathula advocates for a shift in health messaging towards a nutrition-focused approach that emphasizes how the body processes food, alongside promoting physical activity and balanced eating, rather than relying solely on BMI as an indicator of health.
This research underscores the complexity of the relationship between body weight, health, and mortality, suggesting that a more nuanced understanding is necessary for effective public health strategies.
Source: Original article