The fruit/sugar ratios are already in place, and have been for decades without an EU law to state the obvious. It's just rules for rules sake this one.
There is also a difference between EU states as to what is considered the right fruit/sugar ratio. British jam is much nicer than what passes for jam in Italy, just like an Anglo spaghetti Bolognaise compared to a genuine Italian one which we would consider to be a vegetarian version, or the USA'a favourite chocolate bar that only contains about 11% cocoa and wouldn't even be described as chocolate here where we have a 20% min cocoa content.
This just proves that the EU's one size fits all attitude is plain dumb.
The UK Jam Regs (tedious reading)