Recently investigators pay more attention to the relationship between obesity and bronchial asthma (asthma).Obesity is increasingly recognized as a possible risk factor for childhood asthma, and 70% of patients with difficult-to-treat asthma are overweight or obese. In recent years, ketogenic diet, as one of the natural therapies, has been shown to have positive effects on weight loss process; and recent studies showed that ketogenic diet reduced airway inflammation in asthma. This review summarized the mechanisms of associations between obesity and asthma, and described the potential mechanisms of ketogenic diet affecting obese asthma, such as controlling body weight, reducing inflammatory response, regulating intestinal flora and modifying epigenetics, to provide new ideas for the prevention and treatment of obesity asthma.