Also if it was as easy as "Listen to your body" do you think we would be having all these obesity problems now?
Yes! this is a common misconception. "listen to your body" is not the same as "eat whatever you feel like eating". Your tongue/appetite/addictions can tell you many harmful things. Listening to your body requires a lot of training and sensitivity, otherwise my body keeps telling me to eat cakes ;)
Eating sugar releases dopamine. Is that not my body telling me it's good?
The two statements are similar in one way, though: Completely useless as advice that will get people healthier. "listen to your body" will get people to eat what they wan't. "you need to read up on healthy foods/workout routines" will get people to read all sorts of bad advice. Like, for example: "listen to your body".
It is a question of being exposed to a wide array of options and and then of being able to feel what is needed. Compared to a violent craving for sugar and fast food the signal is much more muted.
I'm sorry. This is horrible advice. In fact I would not call it advice at all. Basically you are just saying "do the right thing" without specifying what "the right thing" actually is.