Neck circumference signals risks for heart and metabolic disease. Neck circumference also correlates with coronary heart disease, where the main arteries to the heart narrow and restrict oxygen-rich blood flow. For men, 17 inches (43cm) or greater increases health risks. You could have a healthy weight according to traditional measures, but still face elevated health risks due to neck circumference. And for each additional centimeter of neck circumference beyond these thresholds, death rates and hospitalization rates increase.