The Horsham, Pa., diet company made $23 million, or 63 cents a share, for the quarter ended Sept. 30, up from the year-ago $7 million, or 19 cents a share. Revenue rose to $155 million from $65 million a year earlier.
Analysts surveyed by Thomson Financial were looking for a 52-cent profit on sales of $142 million.
"The third quarter results are a testament to the strength of the business and business model," said CEO Michael J. Hagan. "NutriSystem delivered the best financial results of the year and we're pleased with every important financial and operating metric in the business."
The company said it expects to make 45 to 48 cents a share for the fourth quarter on sales of $123 million to $128 million. Analysts were looking for a 44-cent profit on sales of $121 million.
Shares rose 2 cents late Tuesday to $68.