START ME UP : SUDDENLY, WEIGHT LOSS BECAME HER TOP PRIORITY.

Byline: Heesun Wee Daily News Staff Writer

Who: Jill Felder, 19, of Chatsworth.

What: After weighing in at her physician's office at an all-time high of 259 pounds in February, the 5-foot-5-inch Felder decided a drastic lifestyle change was in order.

How: There's no getting around it. Permanent weight-loss goals can be reached only with regular exercise.

Felder has been heavy all her life, but her February weigh-in was her eye opener.

``I know I've always wanted to lose weight. But I never had the drive to do it,'' said Felder, a Valley College student and assistant manager at a children's clothing store.

``All of a sudden, it just clicked. I needed to do it (lose weight) the hard way.''

Like it or not, the ``hard way'' meant no more fast foods, red meat and butter. Instead, she stuck to a low-fat diet of skinless chicken, steamed vegetables and pretzels.

It also meant a personal get-in-shape program of habitual exercise. She walks three to four times a week now, up to four miles at a time. And she has joined a health club, where she uses a stair-climbing machine, rides a stationary bicycle or joins an aerobics class several times a week.

Besides diet and exercise, Felder credits fenfluramine and phentermine, the controversial appetite suppressants known as Fen-Phen, for helping her achieve her weight-loss goals. Felder used Fen-Phen for eight months before her doctor started weaning her off the diet pills last month. Now she doesn't need the medication anymore.

Felder's game plan for weight-loss is working. She has lost 100 pounds since February and her clothes size has shrunk from a 24 to a 10. ``I want to shop at size 8!'' Felder said.

And as her weight dropped, Felder's self-confidence soared. ``I'm just the proudest person.''

Support from family and friends made a world of difference, she said.

Her sister Cheryl Blair, 37, of Saugus was her weight-loss buddy. She turned to a low-fat diet, regular exercise and Phen-Fen the same time Felder did, and she's also found success by shedding 75 pounds since February.

``We call each other up when we have bad days,'' Felder said.

The sisters even have found a way to avoid succumbing to the diet-busting temptations of Thanksgiving dinner this year: They're planning to celebrate the holiday with a low-fat feast.

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2 Photos

Photo: (1--2) At more than 250 pounds, above, Jill Felder decided a drastic lifestyle change was in order. Today's Jill, right, is 100 pounds lighter.

Bob Halvorsen/Daily News