🤔How to approach someone or making a suggestion without seeming insulting?🤔

How would you approach or go about suggesting to someone to possibly consider fitness, dieting and training in which they could really use in their life whether it's health-related or a mental state of well being, WITHOUT offending them or overstepping boundaries that could be insulting???

What people ultimately decide to do with their lives is there own doing, but what if it's a dear friend, co-working, family member or even significant other?