Now, as the fat cells of our face, chest, arms etc. have more beta receptors than alpha, the fat breakdown is faster and easier.

由于我们面部，胸部，手臂等部位的beta受体比alpha受体多，脂肪分解更快更容易。

句中出现了more beta receptors than alpha， 显而易见，后面的比较分句than alpha是省略了某些东西。

应该是Now, as the fat cells of our face, chest, arms etc. have more beta receptors than （the fat cells of our face, chest, arms etc. have） alpha  (receptors), 

对吗？ 其实这句类似于We have more cars than trucks = We have more cars than (we have) trucks.