I think common sense here can be a guide though. You don't need sugar at all, excluding high levels of anaerobic exercise. Your liver can produce the glucose your body actually needs from other sources (gluconeogenesis) and a lot of your tissues that use glucose also can use fatty acids or ketones. Fructose isn't needed at all. ("low blood sugar" isn't a symptom of not consuming enough sugar, it's a symptom of a disregulated metabolism -- ie insulin resistance or other conditions)
Saturated fats have all sorts of uses biologically.
Saturated fats have all sorts of uses biologically.