Testing for existence of relational data

I've been doing this for a long time in my transformers:

    public function transform($user)
    {
        $data = [
            'id'                   => (integer)$user['id'],
            'name_first'           => $user['name_first'],
            'name_middle'          => $user['name_middle'],
            'name_last'            => $user['name_last'],
        ];

        if (isset($user->emails)) {
            $tf = new UserEmailTransformer();
            $data['emails'] = $tf->transformCollection($user->emails->all());
        }

        return $data;
    }

but the isset($user->emails) line no longer behaves the same way after updating from 5.2.29 to 5.2.45 or 5.3.*. In a nutshell, it used to only run the object through the UserEmailTransformer when the user specifically asked for emails by ultimately running $query->with('emails'), but now it lazy loads the associated emails objects in the transformer right when it hits that line.

I'm simply trying to check if the emails were queried so I can run them through a transformer and, if not, skip that section of code. I can't find anything in the changelogs that would explain this behavior change and I don't know how to do it to make it work unless I don't update Laravel at all. Any help would be greatly appreciated.