LEP and obesity due to melanocortin 4 receptor deficiency: Their circulating levels fluctuate throughout the day in response to the body’s nutritional state, aligning energy intake with energy needs.3 In individuals with obesity, however, these dynamic patterns are frequently dysregulated, potentially contributing to a disrupted energy balance.2,4,5,6 In contrast to the episodic signals of gastrointestinal appetite hormones, leptin functions as a long-term, tonic signal of energy balance.