Can't exclude association's fields from select statement in sequelize

I'm going to answer myself as it might be useful to someone in future. So according to #3664, #2974 and #2975 the answer is the following (thanks to mickhansen):

include: [{
  model: dbcontext.item,
  as: 'items',
  attributes: ['spn'],
  through: {
    attributes: []
  }        
}]

And soon it will be documented.

I realize this thread is a bit outdated, but since this is high in the Google search results and I struggled to find the answer myself, I thought I'd add this here.

If you're using Model.getAssociatedModel() or Model.$get() (for sequelize-typescript), the current answers listed will not work for this use case. In order to hide the model associations you need to add joinTableAttributes: []

Example:

Model.getAssociatedModel({
  joinTableAttributes: []
})

Example:

Model.$get('property', <any>{
  joinTableAttributes: []
});

At the time of this post, joinTableAttributes is not included in the sequelize-typescript types hence the <any>