I used to work in the coffee industry, buying and selling beans across the world. I worked with a lot of producers who bought into FairTrade and the feedback from them and the consumer was rarely positive. Let me explain:
The farmers are guaranteed a minimum price for their coffee. That is what FairTrade is. In order to gain the 'protection' of FairTrade they have to buy into the scheme. However, the minimum price is actually pretty low ($1.40 per lb) - all it really does is ensure that the farmers aren't ripped off by huge organisations (Kraft, Nestle, P&G etc.) offering pennies per pound.
In reality most farmers can sell most of their produce for much more, especially those producing coffee on small single estates. the coffee market also fluctuates dramatically, and when prices are high FT doesn't really do much for the farmers. in effect, for a lot of the time, the farmers are paying out for FT certification when they don't really need it.
So FT isn't actually all that good for the producer. But what about the consumer?
well, FT actually forces lower quality coffee to be delivered under its label. Why? Well, because the producers can sell their high quality beans well over the FT minimum price so obviously don't bother certifying those estates/farms/fields/batches. But they also produce coffee that they can't sell above the $1.40 mark, so they certify it as FT. This includes most Robustas (a lower quality, stronger tasting coffee species - the opposite of Arabica) and low quality Arabicas. So the impact on the consumer is that what you buy under FairTrade is actually much more likely to be lower quality and less delicious.
Now I know this is all about coffee, but it translates into cocoa too. Different product, same mechanism.
From my experience you're much better looking for Rainforest Alliance Certified products - higher quality, more sustainable and well paid farmers.
Anyway, we seem to have got a little sidetracked from diabetes...
