What causes food adversions? certain smell of foods does not agree with my body? it makes me nauseous. please help. thanks

Various reasons: Some people can clearly link their aversion to a specific event. For others there is just no explaining. Early exposure to certain culturally acceptable foods certainly helps set food preference. But the vast majority of food preference is just unexplainable. The gut has a mind of its own. Thank you for not calling this an allergy!