Hey look, it's another diet/exercise thread in which no-one appears to know wtf they're talking about!

High carb/low fat? Are you shitting me? Which of those two do you think provokes an insulin response?
You can't find an activity that doesn't involve your torso? WTF? Have you tried standing up recently? Changing a light bulb? Picking something up from the ground? None of this happens without using your core muscles.
If you don't want to have a fat torso, you have to first not be fat period. Doing crunches won't help you anymore than any other exercise, and in fact will help a lot less than any exercise that uses your whole body (squatting, burpees, deadlifts, thrusters to name but a few). It is highly unlikely that doing a 100 crunches a day will blow up your abs to the extent that they actually protrude THROUGH the layer of blubber that currently surrounds them. Even if it did, you'd still be pear-shaped, and you'd look even more ridiculous 'cause your abs would be the only muscular part of your body!
Cutting out soda - if this wasn't already blatantly obvious to you, yes, do it. But after a while your body will adjust, and it'll stop working for you. Especially if you just start getting those junk calories from other, equally bad, sources.
Walking raises your metabolism to help you burn up your dinner better? Really? Do you realize how difficult it is to make a significant change in the rate of your metabolism, and how minimal the effects of doing so are? The calorific consequences of doing a super-intense workout on your metabolism post-workout are statistically inconsequential; a walk is going to have no impact whatsoever apart from making you hungrier!
ah, just go read crossfit.com and ignore any further advice from gaming slugs. Unless they're me. Or Draft.