What not to do, the experts say, is to keep reaching for those same old baggy duds — at least not after a certain point. Clothes not only make the person, they can make the person feel and look slimmer. And some say that dressing to look your best, no matter where you are in your program, can inspire you and help propel you further downward.

That’s the word from Judy L., a marketing consultant who lost 80 pounds in one year, going from a size 22 to a size 6 or 8.

“When I was eating, I used to go out of my way to get special foods,” says Judy, who asked that her last name not be used. “Then I tried to get my mindset to change, and now I get my rewards in terms of clothes. A piece of layer cake may make you feel good, but looking in a mirror also feels good.”

Clothes can be a barometer of how you feel, as well as how much you weigh, says Madelyn Fernstrom, PhD, director of the University of Pittsburgh Medical Center’s Weight Management Center: “Some people say, ‘I won’t buy anything new until I have lost 15 pounds.'”

If that helps motivate you, that’s OK. The rule of thumb, Fernstrom says, is that losing 8 to 10 pounds translates to going down one size. Still, if you lose “up to 15 pounds, you may be OK in your old size,” she says.

But putting off buying new clothes until you really need them doesn’t work for everyone.

“Before you start dieting, go right out and buy one or two outfits that fit and look great and then wear those to death until you need smaller ones,” suggests Judy L. “Pretty soon they will be swimming on you, and you will look like a little kid in your mother’s clothes.”

What Should I Buy?

Sharon Haver, founder and style director of FocusOnStyle.com, advises dieters to concentrate on flattering, well-fitting basics. “A shirt, a pair of pants; things with a bit of stretch — meaning some Lycra or an elastic waist.”

Pants without a set-in waistband are easier to take in. A-line skirts show the “you” underneath, and, when they get a little loose, won’t look as baggy as a too-large pencil skirt would, she says.

“Why would you want to feel frumpy at any stage of your journey?” Haver asks. “You want people to notice every pound you lose and say, ‘You look fantastic!'”

If you don’t want to break the bank for clothes that will be discarded 10 pounds down the road, shop online auctions, thrift shops, discount malls, or simply buy less expensive brands of clothes than you normally would, Haver says.

Melinda T. has lost 57 pounds in 67 weeks. At first, she winged it, borrowing smaller duds from friends.

“I waited until I had lost two sizes to get clothes,” says Melinda, who also asked that her last name not be used.

“They tell you not to buy elastic waists because you can’t tell if your pants are getting tight on you again, but I like elastic in back. I shop everywhere — Wal-Mart, a hosiery store that has some clothes, thrift shops.”

Melinda bought dark bottoms and mix-and-match tops. “Very basic,” she says.

Though experts advise showing off your slimmer body with proper-fitting clothes, stay away from overly tight ones. Philip L. Goglia, PhD, founder of Performance Fitness Concepts in Santa Monica, Calif., advises clients to buy a slightly larger size than they need while they’re actively losing.

“Buying smaller reminds you of feeling tight,” he says. “Let your new physique come naturally. You don’t need a big old potato sack, though. You need to see your shape change. It’s very motivational.”

Although Fernstrom doesn’t advise buying clothes in your target size, Goglia says it’s all right to buy one piece that might have really “spoken” to you and gotten you inspired to lose, be it a swimsuit, special dress, or whatever.

Put the garment on a hanger, he says, and put it in the kitchen or someplace else where you’ll see it first thing in the morning. Attach a note to it, saying, “This is me. This is my dress.”

Size Insanity

You don’t have to be a dieter to know that sizes are wacky these days. One manufacturer’s 16 may be another’s 18 or 14. Some retailers want it this way — their “proprietary fits” create brand loyalty. And then there’s “vanity sizing,” where a garment that once would have been labeled a size 10 is now a 6.

That’s why Fernstrom does not recommend people set a target size. Go by fit, and not size, which means trying everything on!

And what about those “fat” clothes that — hallelujah! — are now swallowing you?

The experts agree. Toss the larger clothes! Better yet, light a bonfire.

Goglia works with a lot of celebrities. “They are not unlike Joe Civilian,” he says. “They have a fear of gaining the weight back, so they hold onto all their old clothes. When they look in their closet and see the ‘fat clothes,’ it means they haven’t said good-bye to ‘Fat Mary’ or ‘Fat Paul.'”

Besides, who needs a bunch of baggy clothes taking up closet space that you could devote to slimmer-fitting fashions?

“I now feel like I have the right to dress tight,” exults Judy L. What did she do? Bought some Versace jeans. In turquoise.