MARGARET ARGENT lost 10 pounds during her first year practicing law. She wasn't on a diet.

But with $27,500 in law school loans to pay off and a starting salary of $12,600 at her legal aid job, Argent was counting pennies in order to make her loan payments -- and still falling behind.

"I was late in payments and the bank was calling me," said Argent, a staff lawyer with Georgia Legal Services in Waycross, Ga., since her graduation from New York University law school in 1985. Although her office contributed $100 toward her monthly loan payments of about $340, she said, "I'd pay my bills and then I'd have $40 to go to the grocery store with for two weeks."

A year after Argent's graduation, NYU -- like a growing number of law schools -- instituted a loan deferral and forgiveness program. The program aids graduates who, like Argent, want to take low-paying public interest jobs but because of staggering student loan debts can not afford to forego the lucrative salaries paid by many private law firms.

Had it not been for the NYU program, Argent said, "I don't think I could have stayed here at all."

Now NYU contributes about $3,600 annually towards Argent's loan payments. She pays about $40 a month.

For the first three years Argent stays in pubic interest work, the money is considered a loan. After that, the school forgives a percentage until -- if she works in public interest for 10 years -- the loan is totally wiped out.

Concerned about the plummeting percentages of graduates who take public interest jobs -- from a high of nearly 6 percent in 1978 to a mere 3.3 percent in 1985, the most recent year for which figures are available -- 13 law schools have adopted similar programs to defer loan payments, in whole or in part, or to forgive the debts entirely if graduates stay in public interest work long enough. In addition to NYU, schools include Georgetown, Harvard, Yale, Columbia, Cornell, Chicago, Virginia, Pennsylvania, Michigan, Northwestern, Stanford and Southern California.

The programs are designed to counter the effects of skyrocketing college and law school tuitions that can leave young lawyers saddled with more than $40,000 in debt and thus susceptible to the lure of starting salaries that have reached more than $70,000 in large New York firms and nearly $60,000 in the District of Columbia.

"We want to lift the excessive burden of financing legal education off the backs of graduates who wish to perform public interest work but could not afford to pay their monthly bills," Georgetown University Law Center Dean Robert Pitofsky said in announcing the school's loan forgiveness program this spring.

IN PUBLIC interest jobs, Pitofsky said, "the money's terrible -- comparatively terrible -- and so many people who are in debt virtually don't have a choice" but to take jobs with private firms. "A third of our students come out of the school heavily in debt, and they can't afford to make $22,000 and give up $70,000." In fact there's been a steady climb in the amount of debt young lawyers carry. At Harvard Law School, for example, graduates from the class of 1986 had an average of $27,200 in law school loans and total debt averaging $32,800.

Law school placement officials, public interest lawyers, and the students themselves cite several reasons for the decline in numbers of graduates seeking public interest work. They point to a diminishing commitment to society among today's young people, and they also note that public interest law is not an expanding field. Jobs, especially in major metropolitan areas are not easy to find.

"Clearly, the huge salary differential that exists between the private sector . . .and those offered by public interest groups, in the $15,000 range, make it very difficult for students to resist the temptations," said Michael Caudell-Feagan, executive director of the National Association for Public Interest Law. "There's always been a difference," he said, "but the difference has increased dramatically over the last 10 years, and the debt burdens have increased dramatically also."

For Linda Geraci, who is starting her third year at Georgetown and will graduate next year owing about $60,000, the school's new loan forgiveness program will make it "more realistic" for her to take a public interest job.

"You graduate and you think you want to do public interest and you say, 'Wait a minute, I'm $60,000 in debt,' " Geraci said.

Although the Georgetown program will not cover all her loans, Geraci said, without it, "I would definitely be forced into working for a firm for several years."

Joel Ario, director of the Wisconsin Public Interest Research Group (WISPIRG) -- part of a public interest network founded by Ralph Nader -- graduated from Harvard in 1981 with $17,500 in debts and took a $10,000 a year job with MASSPIRG. Without Harvard's loan forgiveness program, Ario said, "I don't think I could have worked for $10,000 a year and paid $210 a month in student loans."

Now, he said although public interest salaries may be higher -- starting pay at PIRGs has risen to $15,000 -- loans have grown even faster.

"I often talk to people who have loan burdens in the $40,000 and $50,000 range. They're on repayment schedules that are $500 and more per month," Ario said. "These programs are critical, increasingly critical."

"High debt is certainly a factor" in students' decisions not to take public intrest jobs, said Ruth Lammert-Reeves, director of financial aid at Georgetown. "The other thing, though, is there are a lot of other expectations that students have in law school, and a high-paying job is going to help them accomplish some of those expectations. They would like to have a certain lifestyle. The fact that they don't have students loan debt doesn't mean that on a $20,000 salary they can live like they'd like to live."

The loan forgiveness programs, she said, do not mean that "all of a sudden you're going to see droves of people going into public interest. What it does is make it feasible for students who are committed."

Ruth Marcus reports on the Justice Department for The Washington Post.