How to do to delete undefined offset 0 in laravel?

I am building app in laravel and when somebody doesn't have fill their data I get undefined offset 0.

Now I am doing something like this to skip that:

Sex: @if($user->user_data[0]->sex == 0) <br />@else <br /> @endif

But what is the easiest way to do it?

Controller:

$user = $this->model->getUserById($id);

if(!$user){ 
    abort(404);
}

return view('user.user', compact('user'));

Model:

$user = User::with('user_data', 'comments')->where('id', $id)->first();

return $user;

via Chebli Mohamed