If a soldier is told they need to start taking medication for high cholesterol, will that affect their continued service?

No it's a very normal thing as long as it doesn't affect their deployability

No , it will not - You would be surprised at how many active members are prescribed Avorastatatin for controlling cholesterol. It is usually prescribed when Chol. levels reach 150 or so, it is a preventative medication, and not a service ending issue. Tell your friend to just be more aware of his diet, and to cut out fast food as much as possible. I know troops don't like eating in the DFAC, but it truly is one of the better options concerning dietary issues.

No and should be no problems with anything