1_Running_this.rb

User.populate 3 do |user|
  user.name = Faker::Name.name

  Interest.populate 2 do |interest|
    interest.user_id = user
    interest.name = Faker::Lorem.words
  end
end

2_Yields_this.rb

#<User id: 5, name: "John Smith">
#<User id: 6, name: "Jane Smith">
#<User id: 7, name: "Bob Smith">

#<Interest id: 10, user_id: 1, name: "Golf">
#<Interest id: 11, user_id: 1, name: "Tennis">
#<Interest id: 12, user_id: 2, name: "Video Games">
#<Interest id: 13, user_id: 2, name: "Soccer">
#<Interest id: 14, user_id: 3, name: "Running">
#<Interest id: 15, user_id: 4, name: "Movies">