Without getting too philosophical about who "I" is and what "my body" means, the simplistic answer is: always. Our bodies give good information, albeit incomplete.
You've been given one life to live and you're the steward of one fantastic, valuable resource: yourself. Our bodies are a combination of all the genetics and history of our families that got us here, plus our experiences, including our grief. That means stored within us is both the thousands of years that lead up to this moment, plus the potential for a thousand more.
Sometimes our bodies talk to us about where we've been, who's hurt us, who's helped us, and what we should be afraid of. Sometimes our bodies are telling us about who we could become. Is the information always accurate? Specific? Complete? No, but it's a good place to start. It's at least information to take note of and heed, even if we don't depend on it entirely for making our decisions moving forward.
Unfortunately I meet more people who distrust their own bodies than people who know how to listen to and value their bodies cues. Americans report valuing "rational thought" but not "intuitive thought" or "communal thought" when all can be helpful (and perhaps even complementary). If you want to get the whole picture and make the best decision, you're going to have to survey more than your own individual mind. Try listening to your community and your body as well.
Unsplash: JF Martin