Here are a couple of videos (also available as podcasts, but you won’t get the visual aids) that I found very interesting regarding activity and nutrition. Basically, ‘Zone 2’ training (and this Zone 2 might be different than other Zones 2 with which people are familiar) is good for increasing your mitochondrial function and fat metabolism. Do a lot of this. But also put in some Zone 4/5 training to keep your glycolytic system working well (but only AFTER the Zone 2 training). Also that being active regularly is of far greater benefit for your overall health than eating well (i.e. someone who is regularly active but doesn’t eat well is likely to be in better health than someone who eats well but spends a lot of time on the couch).
Neither of these is short, but I found them well worth the time investment.