I have made bolognese quite a few times, and usually it tastes great (in my opinion it is better than my mum's recipe). We always use high quality lean minced beef from a butcher (as opposed to supermarket)
When I was making it for dinner tonight, my mum popped in as I was browning the meat and told me not to forget to strain off the fat. I have never strained off the fat before, to be honest there wasn't much fat there anyway as it is lean beef, but decided to do so today.
When we sat down to eat, I found the sauce much less flavourful than normal, and the texture wasn't as creamy. I can only assume that removing the fat caused this effect, as I did nothing else differently.
My mum is very paranoid about her health, as both her parents (my grandparents) have died from a combination of diabetes and heart disease. She already has slightly high blood pressure, which is currently being monitored (no medication). She always strains fat off everything, and never adds salt to food. Is straining off the fat likely to make a big difference, bearing in mind that it is already lean meat?
Disclaimer: Our bolognese isn't really a true bolognese as for religious reasons no dairy products are added to the meat sauce, and we also don't add wine. So it's basically minced beef and vegetables (onions, carrots etc) in a tomato sauce. It still tastes nice though (when the fat isn't skimmed off!)