Obesity is a worldwide epidemic that affects half a billion people. It has been estimated that, if current trends continue, by 2050, 60% of men and 50% of women worldwide will be obese. Hypertrophy and hyperplasia of white adipose tissue caused by overweight and obesity lead to a chronic inflammatory state, which results in impaired insulin sensitivity and the development of diabetes. Currently, the number of people affected by diabetes globally exceeds 400 million (rising more rapidly in low- and middle-income countries). In 2019, diabetes was the ninth leading cause of mortality, with an estimated 1.5 million direct deaths.  This book provides a comprehensive overview of the relationship between inflammation, obesity, and diabetes.