is wholewheat foods actually better for you?

Yes. Basically whole wheats will have more complex sugars, and less simple sugars. Processed grain usually has all but the very heart of the kernel removed, which tends to be much higher in simple sugars. Simple sugars make it easy to spike your blood sugar since your body doesn't have to work hard to break them down, and when your blood sugar spikes it causes your body to squirrel away the extra sugar as body fat. Complex sugars are harder to break down, so they tend to not really spike your blood sugar. They'll also keep you more full for longer. It'll also usually be higher in fiber (the outside of the grain is usually made of cellulose which we can't digest, so it's treated as fiber).