I need a single or double word for a category name for my blog that means: Things that are bad for you, such as smoking, drinking, etc. when you have diabetes. The word must be for all things that can be bad for you.
In disease management, there is often a discussion of risk factors. While risk factors include the negative activities you enumerate, they also include circumstances that are beyond your control, such as age, family history, ethnicity etc.
Perhaps the phrase threat factors may be more suitable to your purpose. The word threat means
a. an indication of imminent danger, harm, evil, etc.
b. a potential source of this
The items you list are more direct threats (and things that can be avoided) than are the broader category of risks.
A typical way of describing this would be vices or weaknesses.
If it's particularly exceptional or specific, maybe call it an Achilles' heel.
But vice I think is the best fit here.
Vice is a practice, behavior, or habit generally considered immoral, depraved, or degrading in the associated society. In more minor usage, vice can refer to a fault, a negative character trait, a defect, an infirmity, or a bad or unhealthy habit (such as an addiction to smoking). Synonyms for vice include fault, depravity, sin, iniquity, wickedness, and corruption.
A rather informal answer comes to mind: A female friend with a particular and dangerous allergy once stated to me "Nuts are my enemy!" - this can be adapted in two quite different ways:
I am diabetic and too much sugary food is my enemy.
Diabetes is my enemy, which I can keep in check with an appropriate diet.