Definitely agree with the fruit before cardio. When I said eating a big meal before working out, I meant eating 2-3 hours before so there's plenty of time to digest and utilise the energy gained, which is what a lot of people find effective.
I think the reason the advice changes so much is because there are so many contradictory studies on the subject, and it's incredibly difficult to actually do controlled studies on human diet due to the practical and ethical difficulties of getting people to stick to whatever you're testing for a long period of time. Instead they rely on observational studies where they survey people and tally up results based of what they say.
There's also the advice of individuals personal experience (eg Marky Walhberg). He's found a groove which works for him - people like that often end up telling everyone that their way is the only way, when that's not necessarily true.