I used to take protein powder - Pro Complex from Optimum Nutrition - because i found it was cheaper than eating meat all the time, but i was told protein powder is bad for you in the long run, so i stopped. Is it true?

If it is, how do i reduce cost of food(following the zone diet has increased my intake of protein so eating has become more expensive)?

First of all, I have never heard that to be true of protein powder. But, I don't really care for all of the additives that are put in many brands, so I usually stick with one brand that has very little added to it.

But, if you choose to go without protein, other sources of inexpensive proteins include cottage cheese, egg whites, soy products. In addition, you can look for bargains as things go on sale. This time of year, you may find that turkey drops big time. Our local store usually has a sale in which you can buy a whole bird for pennies per pound, along with an accompanying purchase. You don't have to save the bird for Thanksgiving; you could roast it up and then freeze the portions for later.

Also, about once per month, our grocery store drops the price per pound on chicken breast, and so I end up stocking up on that. I also watch for sales on extra lean ground beef, and then stock up.

I think you get the picture, it takes a bit of smart shopping.

Not saying anything one way or the other about protein powder other than Soy. A protein powder that might (might!) be bad. It looks like there is conflicting information about Soy being good or Soy having possible long term implications. When you look at some of the findings and reports, it is slowly starting to emerge that it appears that whole foods with Soy - Tofu, edamame (sic?) are good choices, and that processed Soy is what is appearing to have detrimental effects. Just my opinion and my understanding from what I've read about Soy to date.

John, sounds like you and I are reading the same findings and reports. Soy in the form of edamame or other natural forms are likely to be good choices, whereas the soy that is processed and made to look like other foods are probably not the best choices.