Could cooking at home be costing you? According to market research firm NPD Group, grocery aisle price hikes are predicted to surpass restaurant menu price increases for all of 2011. Although supermarket food prices dropped in 2009, they ended up in 2010 and are currently rising faster than restaurant costs — a factor that's driving more Americans out of the kitchen and back into dining establishments. Why the sudden price jump? Fierce supermarket competition during the economic recession kept grocery prices prohibitively low — but meanwhile, costs for commodities like sugar, corn, and pork continued to build. As a result, many analysts expect a grocery bill bubble to burst and food inflation rates to reach notable highs.That's some scary news for the American pocketbook. Have you noticed a jump in grocery costs — and is it driving you to eat out more?