This refers to responding to your body's own dictates when deciding what you want to eat.
It's often mis-interpreted eating whatever comes to mind when you want to eat or spending ages trying to hear what your body wants.
This is understandable after what seems like the rigid control of dieting-it actually isn't control as it just messes with your body's design for self regulation-in the aftermath, your eating may have been so derailed by good/bad foods, disordered thinking stress /tension, that your best bet is to minimize, possibly even abandon any attempts at conscious regulation.
That would be a mistake in the main though because what dieting does wrong is not to have a conscious input in dieting, i.e. considering things other than what you may fancy right now, but a complete conscious take over, making eating mostly a curtailed and a pre destined decision.
Once you abandon that, there's no need to go the whole way, unless you are in a very bad state re your eating.
I must admit, I don't like the term much as it seems to suggest eating is some kind of guesswork. When actually, it's a product of your history, environment/ terrain and personal bio and psychological chemistry.
Whatever the affect of the mental and physical demands on you, will also shape your desire. The obvious is being very hungry or having extended effort=hunger for calorie dense foods as opposed to lighter things.
It's good to think about what you eat overall, in a context of what you've been eating lately. Sometimes we do get into a pattern which we could do with reminding ourselves to get out of, for change and varieties sake.
We sometimes forget what can be on offer, especially if we have limitations of budget and so on. It should be a minority of the influence though and should be in a mediating, supervisory kind of role.