Excess body fat significantly affects insulin resistance by disrupting the body's ability to utilize glucose effectively. High levels of fat tissue, particularly in the abdominal area, can lead to chronic inflammation and hormonal changes that impair insulin action. This resistance forces the pancreas to produce more insulin, which can eventually lead to type 2 diabetes. Maintaining a healthy body fat percentage through proper diet and exercise is crucial in mitigating these health risks and promoting better metabolic function.