I must admit, I haven't read the article, but part of my intense testing over the last couple of days was to investigate late afternoon and evening modestly higher rises. The only difference I could find was drinking more sugar free squash. I cut it out and the numbers have reverted to where I would expect them to be.
I have always had some squash, as even the bottled water elsewhere doesn't taste very good, but I have only just had the rises. I'm concluding slightly more squash, and maybe a little stronger. I will do some targeted testing over the next week or so though, just to absolutely prove it.
To be fair, I was testing every hour, on the hour (in addition to my standard tests), and the highest number I saw was 5.7, so it's just the pedant in me taking over.
Oh well.