Budgets are like diets. Both are tough to define. And neither one is easy to stick to -- especially when you're tempted over the holidays.

Experts say just like diets, budgets tend to be blown more often on the weekends than during the week. The theory: You've deprived yourself all week, so when the weekend hits, your will-power splits.

"It's easier to stick to a budget during the week than on the weekends," says certified financial planner Julie Murphy Casserly, founder of JMC Wealth Management in Chicago and author of The Emotion Behind Money: Building Wealth From the Inside Out.

That's because chances are, you're busy with work, family and household responsibilities Monday morning through Friday afternoon. But when the 5 o'clock whistles blows on Friday, signaling the start of the weekend, the extra free-time and leisurely lifestyle lends itself to letting loose. And to spending.

"That mindset makes it harder to adhere to a budget," says Casserly. "And increases the chance you'll get sucked into the 'holiday hoopla'." But budgets don't have to be filled with angst. In fact, just like a good diet program, with a little support and a few time-tested tricks, you can sail through the holiday season with your budget intact.

And just to make sure you keep your budget goals in sight this shopping season, think of this "Debtor's Diet" as your personal support system.

Pack your presidents

Bill Druliner, Group Manager & Financial Counselor at GreenPath Debt Solutions in Milwaukee, says it's wise to carry "presidential paper", a.k.a. cash, on the weekends. "Leaving your ATM/debit/credit card(s) at home greatly cuts down the chance that you'll blow your budget." Druliner says.

"When I shop with cash, I always spend less that I expect just because I'm afraid of being embarrassed," says Kevin Rider of Syracuse, New York.

"If you're 'good' over the weekend and spend less on eating out or fun, that will leave you more cash to pay down debt, for next week, or to put toward a bigger present for a loved one," says Druliner. "You can also carry funds forward to future weeks if you're really good."

Use the buddy system

To stay on track, Casserly suggests shopping with a pal when you're hunting for Black Friday bargains. But don't pair up with just "anyone." "Shop with an 'allowance buddy,'" Casserly advises. "Team up with someone like a spouse, trusted friend or family member you know will hold you accountable to your budget."

You can even ask your buddy to hang on to your cash or plastic while shopping. Casserly explains: "That will make you really think about a purchase and how it impacts your bottom line."

Check yourself

When the clock strikes 5 p.m. on Friday, Casserly says that's a sign you should whip out your checkbook. "Write a check out to yourself in the amount you wish to reduce your debt by," she advises. Carry this check in your wallet all weekend as a reminder of your long-term budget goals. "You can even wrap it around your credit card to really drive home the point that you don't want to go deeper in debt on holiday gifts," says Casserly.

Whatever you do, experts say if you fall off the diet, don't give up. And don't forget to check back next Friday for more Debtor's Diet tips to help you stay on track but still have fun throughout the holiday season without feeling like a Scrooge.

Need an extra boost of diet support during the week? To get your daily Debt Diet tips, follow WalletPop on Twitter at @WalletPopper and the Debt Diet at @DebtDiet.

Gina Roberts-Grey is a freelance writer specializing in consumer issues.