A 32-year-old man with T1D (treated with an insulin pump), microalbuminuria, OSA, restless legs syndrome and class 3 obesity (BMI: 47.43 kg/m2) experienced a body weight loss of 20.9 kg (−16.1% of total body weight; −15.2% of body fat percentage) over 10 months, while he was on combination therapy with once-weekly subcutaneous semaglutide (at a dose of 0.25 mg/week, increased to 1 mg/week during a 2-month period) and pramlintide (15 mcg pre-meal subcutaneous injections, three times a day). This evidence concerns the gene INS and obesity due to melanocortin 4 receptor deficiency.