High-fat diet exacerbates cognitive rigidity and social deficiency in the BTBR mouse model of autism.

•High-fat diet in BTBR and C57 mice induces severe metabolic impairments.•Exposure of BTBR mice to high-fed diet increases autism-related cognitive rigidity and dampens social memory.•Autism severity score is higher in BTBR mice fed with high-fat diet, and is correlated with weight.•Hypothalamic expression of dopaminergic signaling factors is correlated with autism severity and with weight.