Our cells must metabolize the nutrients we ingest, either using them to make energy or packaging them for storage as carbohydrates and lipids. Overnutrition increases metabolic activity, which is stressful to the cellular protein and lipid processing machinery. Dysfunctional protein and lipid processing is implicated in the progression of several metabolic diseases, including obesity and fatty liver disease. My thesis investigates the molecular mechanisms leading from overnutrition to dysfunctional protein and lipid processing.