What is the secret to eating healthfully?

I'm typing this because I'm eating a blueberry muffin from Costco.  Why am I eating a blueberry muffin?  Because over the last few days, I had a houseful of company and decided that I should serve them with Easter brunch.  I also decided that, because it was my son's birthday, we needed a huge apple pie. 
We apparently also needed cookies and chocolate.  Of course there were leftovers.  Unless I have company, I don't buy this stuff.  Once they're in my house, I  have no self control.    I dive into it like I'm starving.  Sheesh!
There are  tons of books, articles, blogs, etc. about how to eat healthfully.    It's not like I don't know how to do it.  Most people    already know what foods to eat and not eat.  It's not like it's a well kept secret!    But here IS the secret to eating healthfully.   
Don't. Buy. The. Crap. 
If you don't buy it, you can't eat it.  It's that simple. 
​Wish me luck for the next time I have company!