The multitude of obesogenic diets used in rodent studies is enormous and thus hardly manageable. Since standardization is missing and it is presumed that individual compositions provoke individual effects, the choice of quality, quantity and combination of diet ingredients seems to be crucial for the outcome and interpretation of obesity studies. Therefore, the present study was conducted to compare the effects of three commonly used obesogenic diets on selected parameters. Besides basic phenotypic and metabolic characterization, one main aspect was a comparative liver proteome analysis. As expected, the obtained results picture differentiated consequences mainly depending on fat source and/or fat- and sugar quantity. By confirming the general presumption that the choice of nutritional composition is a pivotal factor, the present findings demonstrate that a conscious selection is indispensable for obtaining reliable and sound results in obesity research.In conclusion, we strongly recommend a thorough selection of the appropriate obesogenic diet prior to an experiment and in consideration of the individual research question.