Doctors have long relied on measurements like body mass index (BMI) and waist-to-hip ratios to assess health risks. BMI, which divides weight by height to estimate body fat, doesn’t always tell the complete story. Research shows that people with larger necks relative to their body size face increased risks of several serious health conditions. The connection lies in what neck size reveals about fat distribution, particularly in the upper body. The evidence linking neck size to health problems is striking.