However, consistent with our observation, Ooi et al. [10] described a notable decrease in PCSK9 levels in a sample of 23 overweight (BMI 28.4 ± 3.2 kg/m2) men and women 4 h after fat load, suggesting that the response of PCSK9 may happen only in individuals with obesity. Here, PCSK9 is linked to obesity due to melanocortin 4 receptor deficiency.