By now, we all know the cold, flabby facts about the obesity epidemic in the United States. It's a story that pops up in health magazines and newspapers at least weekly, yet it's largely ignored by the masses, a victim of its own popularity.

We all know that a better diet and exercise regimen is, for most people, the recipe for fitness. But with tempting (and often high-calorie) food just a drive-through away, and with more Americans working more hours a week than at any other time in the nation's history, it's all too easy to ignore that fact.

But let's put aside for a moment the health effects of junk food and a sedentary lifestyle. There's an often-overlooked victim of junk food's reign that needs to be outed: your bank account.

Increase your wallet weight
It's a tricky situation, for sure. You've got to eat, you don't have much time, and the take-out options are endless. Why prepare a home-cooked meal when you can get something equally as tasty from the outside world? While there's nothing wrong with convenience, you pay for that speed at the cash register.

The simple fact is, each of these convenience meals adds up -- and not just on your hips. Every coffee from Starbucks, every lunch from Subway or Quiznos, every drive-through dinner from McDonald's -- what seems like $3.50 here or $5 there can turn into $100 or $200 in short order.

By thinking creatively, you can reduce your waistline while bulking up your wallet. Here's how.

Solutions for a busy family
Make food ahead of time.
When you've got a free weeknight -- or a free Sunday -- make several meals at once and refrigerate or freeze them for the days ahead. They don't have to be fancy -- black beans and rice, spaghetti and meatballs, or a pot of vegetable soup will work wonders on a hungry stomach. And having good, tasty food just a reheat away will lessen your urge to hit the drive-through.

Choose whole foods over processed. Sure, sometimes you've got just enough time to nuke a prepackaged meal before you run off to a meeting. But when you can, choose foods that are less processed. They're often cheaper and healthier -- and if you make or purchase them ahead of time, they take no extra time to warm up. For instance, serving for serving, the aforementioned black beans and rice costs much less than one single-serving microwaveable meal.

Cut back on expensive meats. Eliminate meat from several meals a week, or buy fewer cuts of the expensive meats you like. Though a few dollars here and there may not seem like much, it can add up to big savings month after month. And with all of the pastas, soups, and other meals you'll be making in bulk beforehand (right?), you won't even miss the meat.

Skip grocery-store shortcuts. Does it really take that much longer to hull the ear of corn yourself? The price differential between pre-made and do-it-yourself foods can be hefty. If you have an extra five minutes to dice that onion or bell pepper yourself rather than buying its pre-sliced counterpart, you'll do your wallet a world of good.

Put your money where your mouth is
What to do with all the cash you'll be saving? Invest, Fool. Depending on your risk tolerance and investing experience, you've got a full plate of options. If you want to put your money where your mouth is, why not invest in an exchange-traded fund like the PowerShares Dynamic Food & Beverage (AMEX:PBJ)? You'll instantly gain access to holdings such as Kroger (NYSE:KR), Kellogg (NYSE:K), Dean Foods (NYSE:DF), McDonald's (NYSE:MCD), Archer Daniels Midland (NYSE:ADM), and J.M. Smucker (NYSE:SJM). Granted, it's not the fastest-growing ETF on the market, but with holdings that are virtually recession-proof, it can stay strong through thick and thin.

The Foolish bottom line
You don't have to implement each one of these tips in order to see some results. But making changes to even a few aspects of your culinary lifestyle will help propel you to success -- with both your wallet and your waistline.

Want more tips on how to get your financial matters in order? Take a free trial to Motley Fool GreenLight and hop on the road to financial freedom.

Hope Nelson-Pope is online coordinating editor at The Motley Fool. She owns shares of Starbucks but none of the other companies mentioned. Starbucks is a Motley Fool Stock Advisor recommendation. The Motley Fool's disclosure policy never counts calories.