Methods of increasing the total lipid content in a eukaryotic cell, the total content of polyunsaturated fatty acids [“PUFAs”], and/or the ratio of desaturated fatty acids to saturated fatty acids by reducing the activity of the heterotrimeric SNF1 protein kinase are disclosed. Preferably, the chromosomal genes encoding the Snf1 α-subunit, Gal83 β-subunit or Snf4 γ-subunit of the SNF1 protein kinase, the upstream regulatory genes encoding Sak1, Hxk2, Glk1 or Reg1, or the downstream genes encoding Rme1, Cbr1 or Snf3 are manipulated in a PUFA-producing strain of the oleaginous yeast Yarrowia lipolytica, resulting in increased total lipid content, as compared to the parent strain comprising the heterotrimeric SNF1 protein kinase not having reduced activity.