Gas and groceries. They're two of the categories in which American consumers spend most each month, and neither of which appear to be going down in price anytime soon. According to a Gallup poll, the average American spent $151 per week in food last year, and the Huffington Post reports that Americans spent over $2,000 last year just at the gas pump - that's more than $166 each month!

Taking those numbers into consideration, it's clear that any relief in either category would be welcome to everyday American consumers. That's why Creditnet.com - a leading online authority on credit cards and personal finance - today released its list of the best credit cards for gas and groceries.

According to Creditnet, some rewards credit cards specialize in bonus cash on purchases made at stand-alone grocery stores and gas stations. So for consumers that constantly find themselves on the road and in the grocery store, credit cards for gas and groceries can lend to some serious savings over the course of a year.

Creditnet took into consideration the bonus cash back opportunities available for gas and groceries, a card's spending limits, and other credit card perks like 0 percent interest periods when crafting its list of 2013's best credit cards for gas and groceries.

1.) Blue Cash Preferred® Card from American Express

Creditnet's top-rated credit card for gas and groceries in 2013 is this cash back card from American Express. Why? Because this card rewards the first $6,000 in purchases at U.S. stand-alone supermarkets in a calendar year with 6 percent cash back, or the equivalent of $360 in bonus cash back. Consumers will earn an unlimited 1 percent cash back on grocery purchases thereafter.

Plus, this card will also reward members with 3 percent cash back on gasoline purchases at U.S. stand-alone gas stations and select major department stores. All other purchases earn the standard 1 percent cash back.

This card does require an annual fee of $75 and is reserved for consumers with excellent credit. But for those consumers who are credit-worthy and make a majority of purchases each month on gas and groceries, this cash back option is as lucrative as any in 2013.

2.) Discover it™ Card

While this card isn't currently offering bonus cash back on gas and groceries, past 5 percent bonus categories that rotate each quarter have included similar cash back opportunities. Currently, homeowners can take advantage of 5 percent cash back on up to $1,500 in purchases made this quarter at home improvement stores when they enroll.

Discover hasn't announced the cash back bonus categories that begin July 1st, so cardholders can stay tuned for a May 1st announcement to find out what their "Summer Fun" categories will include.

Along with an excellent cash back program, this card has no annual fee, no interest on new purchases and balance transfers for 14 months, and 1 percent cash back on all non-bonus purchases.

The Discover it Card is Creditnet's favorite cash back credit card of 2013.

3.) BankAmericard Cash Rewards™ Credit Card

This cash back credit card from Bank of America offers consumers 2 percent cash back on groceries and 3 percent on gas for up to $1,500 in purchases in the two combined categories each quarter, and another 1 percent on all other purchases.

This card stands out for it's introductory bonus cash back promotion - $100 on new purchases - and a 12-month 0 percent interest period applied to new purchases and balance transfers. There's also no annual fee and rewards never expire.

Overall, this is an easy-to-follow cash back card great for consumers hoping to earn rewards on gas and grocery purchases, especially.

4.) TrueEarnings® Card from Costco and American Express

Member-friendly companies Costco and American Express team up for a card that rewards consumers with 3 percent cash back on up to $4,000 per year on purchases made at U.S. stand-alone gas stations; consumers will also earn 1 percent cash back on all purchases.

While this card does not offer bonus cash back for grocery purchases, it does reward dining out purchases with an unlimited 2 percent cash back.

This credit card carries no annual fee for Costco members, and the 6 month introductory period applies to new purchases only.

5.) Disney Premier Visa® Card from Chase

That's right, this Mickey Mouse-endorsed credit card from Chase is good for 2 percent in reward dollars on purchases at gas stations and grocery stores (plus most Disney locations).

This card allows for flexible point redemption, including statement credits. The annual fee is $49, and cardholders that spend $500 within the first 3 months from account opening will receive a $100 Disney gift card.

For families with Disney fanatics, young and old alike, this gas and groceries credit cards is one of the best in 2013.

To find out more about how to use credit cards to save on gas and groceries, contact Creditnet Vice President Jason Bushey on Google+.