There are a number of things that have affected the price of foods, at least here in the states ...
Beef - The severe drought in the cattle area's the past couple of years, has caused ranches to have to cut down on their herds drastically. Then add in the major freeze (that was apparently a surprise) in the northwest this past winter that caused major numbers of cattle to freeze to death and you end up with rising prices.
Pork - A Major Porcine Pandemic has been occuring this year that affects baby pigs (only) and the mortality rate (last I remember hearing) was in the MILLIONS. Such a drastic reduction in the number of ready for slaughter pigs has doubled the price of pork.
Produce grown in California - Major drought there as well as the gooberment cutting the water alotments for farms (sometimes to 0) has lead to a shortage of certain produce. Hence a price increase.
Animal Feed In General - With the drought's the cost of animal feed has done nothing but rise the past few years. Used to be able to get a bag of scratch grains for the chickens (which isn't really necessary but they respond well to going back into their coop with a bit sprinkled on the ground) has risen from $8.00 to over $14.00 a bag. And that's just for my little flock of hens.
Combine them all together and you have price hikes across the board. The only reason "junk food" hasn't gone up is because it's mostly chemicals and GMO based foods which are HIGHLY subsidized in the U.S.
This is why I've been experimenting with growing my own as much as I can. I don't think this will resolve itself any time in the near future, sad to say.