ABCG2 and obesity due to melanocortin 4 receptor deficiency: After KEGG pathway enrichment, the top 20 significantly enriched pathways in the HFD-R mice are shown in Figure 5, i.e., AA metabolism, caffeine metabolism, purine metabolism, ABC transporters, etc. Considering the rich factor, p value and number of counts, the AA metabolism pathway emerged as the top 1 pathway, and was, accordingly, deemed to be the metabolic pathway with the greatest impact on the differential metabolites between the HFD-P group and the HFD-R group, providing a reference for future anti-obesity researches.