The upcoming week is chock-full of important events for those with an eye to the food industry. These events will cover everything from the fate of traditional grocers to the natural/organic food movement to the battle over GMO labeling.

Here's what you should keep your eye on.

Tuesday
On Nov. 5, citizens in the state of Washington will get to vote on Initiative 522: whether food products containing genetically modified organisms, or GMOs, must be labeled as such. The issue has been hotly debated, pitting big agribusiness led by the likes of Monsanto (MON) -- one of the country's largest producers of GM seeds -- against several food activist groups.

Source: Alexis Baden-Meyer, via Wikimedia Commons.  

However the vote turns out, it is highly unlikely that it will be the end of the story. California had a similar ballot initiative last month that was narrowly defeated. And even if GM seeds end up being harmless to both humans and the environment, some from within the GM camp are starting to realize the long-term futility of waging such a PR battle.

Wednesday
One grocery store that has taken a definitive stand on GMO labeling is Whole Foods (WFM). The company will be requiring all foods containing GMOs to be labeled by 2018. If this turns out to be a huge boon for the company, other grocers could follow suit, making Tuesday's vote a moot point.

Whole Foods will also be reporting earnings on Wednesday. Both the company and the stock have been on a roll lately. Revenue is up 13% over the last three quarters, and shares of the company are trading about 40% higher in 2013.

The three biggest metrics to watch with grocers are same-store sales, sales per square foot, and profit margins. Whole Foods has been one of the best in the business when it comes to these metrics; a solid quarter would translate into same-store sales increases of at least 7%, sales per square foot of roughly $240, and a profit margin north of 3.9%.

Thursday
One company looking to take a slice of the natural/organic market from Whole Foods is Sprouts Farmers Markets (SFM 0.13%). The company is based in the American Southwest, but is looking to make inroads across the country as quickly as possible.

Though I still have qualms about the company's valuation, I was certainly proven wrong last quarter when Sprouts posted same-store sales increases of more than 10%. Growth like that is crazy, and it is that single metric that I'll be looking at the most closely on Thursday. If Sprouts is able to show that last quarter wasn't just a flash in the pan, we could have a serious growth stock on our hands here.

Source: Sprouts Farmers Market.

Finally, we have one medium-size traditional grocer that will be reporting as well: Midwest-based Roundy's (NYSE: RNDY). Though the company has a natural/organic chain that is doing well in Chicago, the vast majority of its stores have been showing negative growth for all but one quarter out of the past two years.

Two things to look for when the company announces are whether or not it will speed up its expansion in Chicago since Safeway decided to exit the market, and if it is able to at least show positive same-store growth.