The prevalence of overweight and obese cats in North America is high; increasing the risk of development of secondary health conditions in these cats. Obese cats often struggle to lose weight and maintain weight loss long-term. However, a drastic restriction of dietary energy is not recommended for obese cats due to risks of feline hepatic lipidosis. Choline, a nutrient involved in one-carbon metabolism and phospholipid biosynthesis, has been explored as a means to increase hepatic lipid mobilization and improve hepatic health and body composition in humans, rodents, and livestock. However, there is no data supporting the use of choline supplementation in overweight and obese adult cats. Although L-carnitine supplementation has been researched, the results are inconsistent. The objectives of this thesis were to 1) review current knowledge surrounding choline on hepatic health and obesity, with a focus on cats, 2) evaluate choline above published recommendations on serum lipid, lipoprotein and metabolomic profiles, energy expenditure and body composition in overweight and obese cats, 3) conduct a dose-response study to determine the optimal dose of choline for lipotropic activity in overweight cats, and 4) compare the lipotropic effects of choline to L-carnitine in obese cats. Choline at five and six times the published recommendation increased several serum lipids and lipoproteins in obese and overweight adult cats, respectively; suggesting greater hepatic lipid mobilization. Choline at six times the published recommendation also increased one carbon cycle metabolites in overweight cats, suggesting improved methyl donor status. Choline did not change body weight or composition in obese cats. Choline increased serum lipids and lipoproteins to a greater extent than L-carnitine in both lean and obese cats, but did not change serum metabolites, energy expenditure, or body composition. However, obese cats presented with hypothesized disturbances in one-carbon metabolism, previously not reported in cats. Research investigating how choline supplementation may change gene expression in regards to lipolysis and lipogenesis and quantifying hepatic lipid concentrations with supplementation is necessary. The possible differences in one-carbon metabolism between obese and lean cats and how this may contribute to the development of feline hepatic lipidosis warrants further investigation.