Fabp1 gene ablation (LKO) diminishes the impact of high fat diet (HFD) on brain N-acylethanolamide (NAE) levels. C57BL/6N male and female WT and FABP1 gene ablated mice were fed HFD or control diet, fasted overnight, and brains removed/flash frozen and stored at −80°C. LC-MS analysis to quantify N-acylethanolamides using deuterated internal standards (Cayman Chemical) was performed as described in Materials and Methods to quantify (A) arachidonoylethanolamide (AEA), (B) oleoylethanolamide (OEA), (C) palmitoylethanolamide (PEA), (D) docosahexaenoylethanolamide (DHEA), and (E) eicosapentaenoylethanolamide (EPEA). Results are expressed as the molar ratio of each NAE in High-Fat/Control diet and presented as mean ± SEM (n = 8); *, P < 0.05 for LKO vs WT; #, P < 0.05 for female (F) vs male (M).