INS and obesity due to melanocortin 4 receptor deficiency: Upon laser irradiation, the designed nanosandwich (P3‐HA/PM@BP) effectively inhibits obesity development in obese mice, increases M2/M1 ratio in AT, reduces the serum levels of cholesterol/triglyceride and improves insulin sensitivity, exhibiting promising research potential to facilitate the clinical development of modern anti‐obesity therapies.