Forbes.com

The most popular New Year resolutions are to lose weight and to spend less. Many of us would like to accomplish both. Here we apply the philosophy and mechanics of the most popular diets of 2011 to personal finance. Is the Atkins Diet right for your budget, or are you more of a Slim-Fast spender? Continue to find eight effective ways to put the pounds in your wallet--you just might lose some weight in the process.

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1. Weight Watchers

Counting calories in and out may not be fun, but it is effective. Same goes for your budget: If you're spending more than you're earning, your bank account loses weight. Weight Watchers fans count calories--called Points--and you can do the same by tracking every expense down to the penny. Keep a daily diary of your spending and look it over before you go to bed.

2. Atkins Diet

Atkins is one of the strictest but most effective popular diets today. Devotees eliminate carbs and sugars and live on meats and veggies. It is subsistence eating. Sounds harsh, but Jennifer Aniston's body is a sure sign it works. Put your budget on the Atkins diet for surefire, immediate results. It's subsistence spending: eliminate any extra expenses and watch your bank account grow.

3. South Beach Diet

The South Beach Diet starts out harsh (No carbs! No fun!) to get the dieter's body in check but gradually adds natural sugars and carbs at easy-to-metabolize rates. To find out how many carbs (read: discretionary spending) your budget can withstand, apply the South Beach theory. For two weeks cut all extras (movies, happy hours, manicures, take-out) from your spending. On the third week reintroduce one, and so on. You'll be surprised at how much more you enjoy them.

4. NutriSystem

NutriSystem cuts out the guesswork of dieting with pre-packaged meals delivered to the dieter's doorstep each morning. The company says the plan helps dieters avoid cheating or making bad food decisions. To avoid bad spending decisions, try to keep all of your money in savings and set up a direct-deposited allowance each week into your checking account. A finite amount of money each week will keep temptation in check.

5. Slim-Fast

A person can easily spend $50 to $100 on lunch each week eating out. Use the SlimFast "meal replacement" mentality and switch out two store-prepared meals every day with healthier, more budget-friendly meals made at home. A muffin and coffee? $3.50. Hearty oatmeal and home-brewed coffee? Under $1. The same goes for your lunchtime salad. Your wallet--and your waistline--will thank you.

6. The 400-Calorie Diet

This strict diet, introduced in 2010, allows only meals under 400 calories, with no exceptions, keeping portion control in check. The same rule can be applied to your spending habits: Only buy products or services when they're on sale. Not on sale? Non-negotiable. Wait until it is.

7. The Zone Diet

Zone dieters formulate their meals at a very specific 30% protein, 30% fat and 40% carb ratio. Follow their lead when revamping your budget for the New Year and adjust expenses accordingly. One-third living expenses, one-third savings and the rest on fun.

8. Dr. Seigal's Cookie Diet

The success of Seigal's Cookie diet lies in the sweet cookies his clients pop throughout the day, making a day of grueling dieting seem less like self-deprivation and more like a treat. Try this: Use your AmEx card for all expenses for one month--even your morning coffee. It will seem sweet all month long, until your statement comes in the mail. A single statement will help you track where your money is going, and you'll have no choice but to pay it off in one fell swoop.