The obesity epidemic is driving the increased prevalence of nonalcoholic fatty liver disease (NAFLD) globally. The more aggressive subtype of NAFLD, nonalcoholic steatohepatitis (NASH), can lead to progressive disease and ultimately lead to cirrhosis, liver cancer, and death. There are many unmet needs in the field of NAFLD including understanding of molecular mechanisms driving disease, natural history, risk for liver cancer, and most importantly FDA approved therapeutics. Animal models serve as a tool to aid in answering some of these questions. Here, we describe the diet-induced animal model of NAFLD (DIAMOND), a mouse model with many characteristics that mimic human NASH.