Does anyone have any idea about whether I can legitimately substitute blackberries (from local hedgerow, frozen) for blueberries in the blueberry and green tea shake (or other recipes)?

Hi Yumelda,
I don’t see why not. They are about 3 cals more and have less carbs than blueberries for the same weight. I’ve been using them in the green tea shake because they are abundant where I live. I find all the seeds a bit annoying so I leave the shake to settle for a few minutes so they go to the bottom.

Thanks Cherrianne. Good tip – I will do that 🙂