Taking advantage of a previously established obesity and weight loss study (62–64), which was alternate day fasting (ADF) combined with a low carbohydrate diet (30% carbohydrates, 35% protein, and 35% fat), we asked if CCL22 played a role in obesity and ADF-mediated weight loss (Fig. 8M). This evidence concerns the gene CCL22 and obesity due to melanocortin 4 receptor deficiency.