How could regression analysis be used to determine the impact of certain lifestyle factors (e.g., diet, exercise, smoking) on specific health outcomes (e.g., heart disease, life expectancy)? life)?

How could regression analysis be used to determine the impact of certain lifestyle factors (e.g., diet, exercise, smoking) on specific health outcomes (e.g., heart disease, life expectancy)? life)? What challenges might researchers face in drawing conclusions based solely on regression results, and how might they mitigate them?