The present invention provides a method of regulating fatty acid metabolism in a cell by contacting the cell with a modulator of miR-378 and/or miR-378* activity or expression. The present invention also provides a method of treating or preventing a metabolic disorder, such as obesity, diabetes, or metabolic syndrome, in a subject by administering to the subject an inhibitor of miR-378 and/or miR-378* expression or activity. Methods of treating or preventing pathologic cardiac hypertrophy, cardiac remodeling, myocardial infarction, or heart failure in a subject by inhibiting the expression or activity of miR-378 and/or miR-378* in a subject are also disclosed.