WAI-ARIA の練習として(私には、まぁ一応じゃ〜ないくらいのハイレベルだけれど、回答は「まぁ〜一応」のレベル？）

JavaScript 
<!DOCTYPE html>
<title></title>

<style type="text/css">
p[role="radiogroup"][aria-disabled=true] {
  background : #ddd;
  color : #888;
}
p[role="radiogroup"][aria-disabled=false] {
  background : #fdd;
}
</style>

<body>
<form id="test" action="#">
  <p role="radiogroup" aria-controls="times" onclick="hoge.call(this, event)">
    <input type="radio" name="food" value="0" checked>食事無
    <input type="radio" name="food" value="1">食事付
  </p>
  <p role="radiogroup" aria-disabled="true" id="times">
    <input type="radio" name="time" value="0" disabled>朝
    <input type="radio" name="time" value="1" disabled>昼
    <input type="radio" name="time" value="2" disabled>晩
  </p>
  <hr>

  <p role="radiogroup" aria-controls="types" onclick="hoge.call(this, event)">
    <input type="radio" name="car" value="0" checked>車無
    <input type="radio" name="car" value="1">車付
  </p>
  <p role="radiogroup" aria-disabled="true" id="types">
    <input type="radio" name="type" value="0" disabled>普通
    <input type="radio" name="type" value="1" disabled>大型
  </p>

  <hr>
  <p><em>本当は、これでいいのでは？</em><p>
  <p>
    <input type="radio" name="food_time" value="0" checked>食事無
    <input type="radio" name="food_time" value="1">朝
    <input type="radio" name="food_time" value="2">昼
    <input type="radio" name="food_time" value="3">晩
  </p>
</form>

<script type="application/javascript; version=1.8">

(function () {
  
  var setDisable =
    function (n, state) {
      n.disabled = ('undefined' === this.state) ? state: this.state;
    };


  var hasRole =
    function (n) {
      return (this) ? n.getAttribute ('role') == this: !! n.getAttribute ('role');
    };


  var isRadio =
    function (n) {
      return hasRole.call ('radiogroup', n) || ! ('INPUT' != n.nodeName || 'radio' != n.type)
    };


  var setter = function (evt) {
    var target = evt.srcElement || evt.target;
    var doc  = this.ownerDocument;
    var group_name;
    var radio;
    var state;
    var parent;
    
    if (isRadio (target))
    if (hasRole.call ('radiogroup', this))
    if (group_name = this.getAttribute ('aria-controls')) {
      parent = doc.getElementById (group_name);
      radio = parent.querySelectorAll ('input[type=radio]');
      state = parent.getAttribute ('aria-disabled') != 'true';
      Array.forEach (radio, setDisable, {state :state});
      parent.setAttribute ('aria-disabled', String (state));
    }
  };

  this.hoge = setter;
})();


</script>