Prime example: Fidelity within marriage (one of the Ten Commandments). People who cheat on their spouses not only do damage to their relationship, but also increase their own (and their spouse's) risk of being infected with a sexually transmitted disease.
Look at some of the sex-related stuff in Leviticus, like the prohibition on having sex while a woman has her period. Turns out, a woman is at greater risk of getting an STD during this time. So, like the Jewish dietary laws, this prohibition actually helped keep the Jewish people (relatively) healthy.
Or look at the religious rationale for prohibiting prostitution: It treats the prostitute (often a woman) as an object rather than a person with innate dignity, and even in cases where the prostitute is making a seemingly free choice to engage in the transaction, there are often hidden pressures (addiction, mental illness, a pimp) that affect her ability to make a truly free choice.
Those are just three small examples, but there are many others.