Inhibition of diacylglycerol acetyl transferase 1 is of great interest in the treatment of diabetes, obesity and other diseases that constitute the metabolic syndrome. Small molecule inhibitors of the enzyme are often dogged with physicochemical property-related problems such as poor solubility. Herein, the optimisation of a series of biphenyl acetic acid inhibitors is reported. Focus on ligand efficiency and ligand lipophilicity efficiency and a strategy based on conformational restriction led to compounds with excellent potency and ADMET properties, culminating in the discovery of AZD2353.