So, of course, you should want to avoid genetically modified foods. The bad news is that GMO foods are creeping more and more into the food supply chain (see here: http://www.nytimes.com/2009/08/29/business/29gmo.html?_r=1) The good news is that an industry group is working to label food items free of GMO ingredients (see the same NYTs article).
Until that day comes, however, there one thing you can do now in the supermarket if you want to avoid GMO fruits and vegetables (and they're not always labeled). It's a handy trick that someone told me about. Read the little stickers with four numbers that are on every item in the produce aisle. If the first number is 8, it means it's GMO (sometimes the numbers are stamped on the bag the produce comes in as well).
Additionally, if the four numbers start with the number 4 its conventionally grown, and if they start with 9 it's organic.So just remember "I hate eight, but if its nine it's mine."
And, if there already wasn't enough of a reason to avoid processed sugar, check this out from the NYT's piece:
The most recent agricultural sector to convert is sugar beets. Once this year’s crop is processed, close to half of the nation’s sugar will come from gene-engineered plants. Monsanto,
a major developer of such seeds, has said it plans to develop biotech wheat, and scientists are moving forward on other crops.