It seems to me that the biggest reason that the Paleo diet AND the Lowfat Raw Vegan diet BOTH work for losing weight and getting into "better" shape for nearly EVERYONE (especially overweight and obese people) is thus: On Paleo (say Mark Sisson's Primal Blueprint), the simple sugar carbs are clean BUT RESTRICTED so they aren't helping high dietary fat turn into the fat that you wear (the opposite of say, what DONUTS do). Inversely, on a lowfat Raw Vegan diet (like Doug Graham's 80/10/10), eating LOTS of clean simple sugars (fruits) while eating VERY LOW dietary fat causes a similar effect -- your body isn't converting anything to the fat that you wear. (unless you consume more calories than you are burning on EITHER diet of course!)
So, as long as we just keep our simple sugars FAR AWAY from our intake of dietary fats (i.e. not within the same meal), and don't overconsume more than we burn, we can EASILY stop producing the fat that we wear as long as the macronutrient ratio is not completely wacky (like 100% fat!).
Then, it comes down to a matter of what is a healthy, BALANCED macronutrient ratio for YOU.
A bodybuilder, a marathon runner, and YOU will all have widely different macronutrient ratio requirements to achieve your particular goals. There is NO perfect ratio because of this fact. Use common sense, listen to your body, and for goodness sake BE OPEN to things that go against your DOGMA (because your belief, no matter how ingrained, could be modestly or even BLATANTLY UNTRUE).
Just quit eating processed food that comes in a box or a bag and that will be a HUGE start to controlling your health! All the rest is mainly minutiae (though it seems that's all we have to gripe and argue with each other about ;)
Keep it real!
-Eric