I like hummus for snacks too, especially on crackers with Marmite (or Vegemite) for a bit of extra zing.
You have had a good reduction in your PSA in a period that might be a little more than three months. What you are doing seems to be working too so keep it up! I agree that there can be no doubt that diet is a factor in PCa, but it's probably true that the same diet won't work for everyone. It is for each of us to find what works for us as individuals, and go with that.
A question Your statement above:
I think the main reason for the PSA rise slowing this time is reverting to low sugar.
Can you explain that please?
When I started on this diet, I "accidentally" went low sugar without intending to. With my favorite cakes and
cookies commonly containing butter and/or milk, I avoided them all and as a side effect, avoided a lot of sugar. During that first 3.5 months my PSA held at 0.4.
During my next three months I "discovered" vegan
cookies ~ no dairy, but loaded with sugar. My PSA during that period went from 0.4 to 0.6 ~ ouch!
During the last three months I reverted to my previous low sugar regime ~ no vegan
cookies, and a few other small changes like no dates (the fruit!) and no honey. My PSA went from 0.6 to 0.7.