Maternal HFD feeding during lactation impairs hypothalamic neurogenesis in early postnatal offspring but lasts a longer period in males. A–C) Immunostaining (left panel) and quantification (right panel) of BrdU+ cells in hypothalamus of male pups on postnatal A) day 9, B) day 15, and C) day 21 (n = 5–7). D–F) Immunostaining (left panel) and quantification (right panel) of BrdU+ cells in hypothalamus of female pups on postnatal D) day 9, E) day 15, and F) day 21 (n = 5–7). G) The gene expression of cell proliferation maker MKI67 and neuronal differentiation markers (NEUROD1, 2 and 6) in the hypothalamus of pups on postnatal day 15 (n = 5) MKI67, Marker of Proliferation Ki‐67; NEUROD, Neuronal Differentiation. Scale bars, 100 µm. Values are represented as mean ± SEM and analyzed by unpaired Student's t‐test. Differences with p < 0.05 were considered significant. *p < 0.05, **p < 0.01.