Meteor: Set helper for setting checkboxes in template

I am using alanning:roles to check for roles:

helper.js

Template.user.helpers({
    var loggedInUser = Meteor.user()
    var admin = (Roles.userIsInRole(loggedInUser, ['admin'])) ? true : false,
        editor = (Roles.userIsInRole(loggedInUser, ['admin'])) ? true : false;
    var roles = { admin: admin, editor: editor };
    return roles;
});

template

<template name="user">
    <form>
        <input type="checkbox" name="admin"> Admin
        <input type="checkbox" name="editor"> Admin
    </form>
</template>

How do I set the checkbox to checked if admin or editor is true? Or is there a better way to set the checkboxes checked?