Body odor is individually specific and potentially a rich source of information about its producer. Odor individuality partly results from genetic individuality, but the influence of ecological factors such as eating habits are another main source of odor variability.

Researchers at the Department of Anthropology at the Charles University in Prague tested the effect of red meat consumption on body odor attractiveness.

Seventeen male odor volunteers were placed on either a "meat" or "nonmeat" diet for 2 weeks wearing axillary pads to collect body odor during the final 24 h of the diet. Fresh odor samples were assessed for their pleasantness, attractiveness, masculinity, and intensity by 30 women not using hormonal contraceptives.

The same procedure was repeated a month later with the same volunteers, each on the opposite diet than before. Results demonstrated that the odor of volunteers when on the nonmeat diet was judged as significantly more attractive, more pleasant, and less intense. This suggests that red meat consumption has a negative impact on perceived body odor.
Reference:
Havlicek J, Lenochova P. The effect of meat consumption on body odor attractiveness. Chem Senses. 2006 Oct;31(8):747-52. Epub 2006 Aug 4. PMID: 16891352.