How did William Shatner become so fat?

The answers I found here were quite eye opening--I still am quite fit and very trim even though I am older and don't reallly exercise much- never an issue--seems many have a perception that older equates -fat...so untrue..i would ume there was quite a bit of medication involved--especially since the episode with the death of his wife and his bout with depression--the medication that is most commonly perscribed for that, like seraquel and zyprexa, have a very bad side effect--- intense weight gain in a short period of time that is usually extremely difficult if not impossible to get rid of.