Yes, I do believe there is a connection. Clutter affects us mentally, which then affects us physically and emotionally, which then sends a subliminal message to comfort ourselves.
I used to teach basics of feng shui, of which rule #1 is to clear the clutter. I just wish my darling groom understood that, when I have created an empty space, it's not so that he can fill it - haha! Unfortunately, I am currently overwhelmed by clutter, with 2 college kids constantly moving in and out, my husband with his "projects" in the kitchen or garage, my mom popping in and out to spend weekends, and 2 furry creatures (I'm allergic to) creating their own adventures around the house.
I'm constantly de-cluttering, only to be thwarted by all the activity. Keeping the kitchen counter clear is a challenge (as someone in this house thinks that things should be out where they can be seen, rather than put away where they need to be found - haha!).
When your spaces are clear, you feel more energized, and more like you can exercise - which translates to better eating habits and weight management.
The ancient Chinese are who taught us these things. Peter Walsh practices what he preaches, too - he's awesome!