Recent epidemiology (13,644 participating subjects) reveals that skeletal muscle mass strongly correlates with improved insulin sensitivity. With each 10% increase in skeletal muscle index (a measure of how much muscle is on one’s body), HOMA-IR (a measure of insulin resistance) saw a relative reduction of 11%. Folks with higher insulin sensitivity have better glucose control (carbs don’t destroy them) and lower rates of diabetes. Another study looked at the relationship between sarcopenia, or muscle wastage, and insulin resistance. There was a distinct relationship between sarcopenia and insulin resistance, independent of obesity, which can also exacerbate insulin resistance. So, based on epidemiology, a lack of muscle is linked to increased insulin resistance and poor glucose regulation. This should go without saying, but sarcopenia was also linked to obesity.