right - I see that they are high in carbs, I have cut out bread now for about 5 days so don't want to introduce any more carbs. Thanks everybody for your replies.
I love them, I have a lychee tree in my garden, but unfortunately mine are not as sweet or as big as the ones I normally purchase. Mine are a bit more tangy, probably the tree is not getting the right nutrients!
Same as most fruits, eg apples, different varieties taste differently. The tinned ones are normally very sweet and made sweeter still by the syrup. Fresh are much better.