Obesity has now reached epidemic proportions worldwide, which has serious consequences because obesity is associated with various chronic human diseases such as diabetes, hypertension and cardiovascular diseases. With the aim to protect oneself against obesity and debilitating diseases caused by a high-fat diet, we are using a synthetic biology approach to design an Escherichia coli strain (called Fit Coli) that has an enhanced ability to uptake and convert excess fatty acids from fatty foods into a-linolenic acid (ALA). The strategy is to engineer the fadL and fadD genes along with three desaturase genes to facilitate the uptake of long-chain fatty acids and their biotransformation to ALA by the “Fit Coli” strain. It is predicted that the ALA converted from excess fatty acids by Fit Coli is converted to docosahexaenoic acid (DHA), an omega-3-fatty acid, in the human gut, which is well known to have many positive health benefits.