Someone tat stands up for something
I believe the answer is: Eat a well-balanced diet to increase energy and immunity
Even though physical activities improve both our energy and immunity in the long run, they are not as significant as maintaining well balanced diet in your life.
You need to make sure that you get your nutrients from various source of non-processed food in order to fulfill both your macronutrients and micronutrients.
body language, has he been acting weird? Agreeing or disagreeing in a joking way, lot of eye contact, complements you, the way he responds to touch (like a hand on his shoulder, holding his hand, ect.), and does he lean forward when your speaking to him despite already sitting close
