DOW JONES NEWSWIRES NutriSystem Inc.'s (NTRI) first-quarter profit tumbled 45% on higher marketing costs. But shares rose 7.6% after-hours to $19.90 as the weight-management company's results were better than feared. The stock had fallen 41% this year through Monday's close. Chairman and Chief Executive Joe Redling said, "We expect new customer starts to continue to strengthen in the second quarter and anticipate modest revenue growth year over year for the balance of the year." Results have been weak of late as the downturn saw less consumers spending discretionary money on weight-loss products. The company is also chasing shoppers in new venues such as Walgreen Co. (WAG) drugstores and Wal-Mart Stores Inc.'s (WMT) Sam's Club wholesale warehouses, expanding its reach further beyond its mail-order roots. NutriSystem reported a profit of $4.8 million, or 15 cents a share, compared with $8.8 million, or 29 cents a share. Revenue fell 1.8% to $158.8 million. In March, the company issued downbeat guidance predicting earnings of 10 cents to 13 cents on revenue of $152 million to $157 million. Gross margin rose to 54.6% from 53.3%, but profit fell on a 21% jump in marketing costs. -By Shayndi Raice, Dow Jones Newswire; 212-416-2672; shayndi.raice@dowjones.com