We report the case of a 17-year-old woman with anorexia nervosa (AN) who developed an abetalipoproteinemia-like lipid profile and acanthocytosis. These abnormalities resolved slowly as her nutritional status improved. We considered 3 possible causes of an abetalipoproteinemia-like lipid profile in AN: (1) depletion of hepatic substrate for apolipoprotein B synthesis, (2) lack of exogenous fatty acids with exhaustion of endogenous stores of triglycerides in adipose tissue, and (3) preservation of the lipoprotein lipase (LPL) mass. This unusual case provides important clues that enhance our understanding of lipid metabolism under exogenous and endogenous fat deprivation and highlights the pivotal role of LPL as a gatekeeper of the energy source.