Scope High red meat and sucrose consumption increases the epidemiological risk for chronic diseases. Mechanistic hypotheses include alterations in oxidative status, gut microbiome, fat deposition, and low-grade inflammation. Methods and results For 2 weeks, 40 rats consumed a diet high in white or red meat (chicken-based or beef-based cooked mince, respectively), and containing corn starch or sucrose in a 2 x 2 factorial design. Lard was mixed with lean chicken or beef to obtain comparable dietary fatty acid profiles. Beef (vs chicken)-fed rats had higher lipid oxidation products (malondialdehyde, 4-hydroxy-2-nonenal, and hexanal) in stomach content and blood, and lower blood glutathione. Sucrose (vs corn starch)-fed rats showed increased blood lipid oxidation products and glutathione peroxidase activity, higher liver weight and malondialdehyde concentrations, and mesenterial and retroperitoneal fat accumulation. Beef-sucrose-fed rats had increased cardiac weight, suggesting pathophysiological effects on the cardiovascular system. The colonic microbiome of beef-sucrose-fed rats showed an outgrowth of the sulfate-reducing family of the Desulfovibrionaceae, and lower abundance of the Lactobacillus genus, indicating intestinal dysbiosis. Blood C-reactive protein, a marker for inflammation, was not different among groups. Conclusions Consumption of a cooked beef-based meat product with sucrose increased oxidative stress parameters and promoted cardiac hypertrophy and intestinal dysbiosis.