Nutrisystem has signed NFL Hall of Famer Terry Bradshaw as a spokesperson to join fellow Hall of Famer and former QB Dan Marino in national marketing.

Meanwhile, ads featuring Charles Barkley broke during the NBA’s opening day on Dec. 25, not for basketball but for Nutrisystem rival Weight Watchers.

The campaign, “Lose Like a Man,” may be new for the basketball Hall of Famer, but not for male athletes and weight-loss programs.

When it comes to trying to win the battle over the male waistland, Nutrisystem was far ahead of Weight Watchers in using spokesmen closely associated with sports. Past campaigns have included Mike Golic, Don Shula, Chris Berman and Charlie Manuel. The company earlier this month also signed Janet Jackson.

“Barkley, Bradshaw and Marino are relevant and credible to even the most casual fan, whether pre-ESPN or post Nike Air,” said John Meindl, founder and president of SportsBrandedMedia, a New York-based marketing, product placement and production company. “For men that need a little help in getting over the fence, these brands have strategically played both sides, enabling wives and girlfriends to use the power of stars.”

Bradshaw will support Nutrisystem even as he is seen nationally as an NFL analyst and co-host of Fox NFL Sunday. Nutrisystem said it would feature Bradshaw individually, as well as with longtime spokesman Marino, in a testimonial-style ad campaign as part of its 2012 diet season efforts aimed at the men’s market.

To date, Bradshaw, who played 14 seasons with the Pittsburgh Steelers and was the first quarterback to win four Super Bowls, has lost 32 pounds on the Nutrisystem Success en route to his goal of shedding 40 pounds.

Weight Watchers’ campaign bring Barkley, an 11-time All-Star during his 16-year playing career, to the forefront at time when he will be seen nationally on a regular basis as an analyst/commentator for TNT’s coverage of the NBA.

“Dieting is not a man’s world because we don’t like to diet—we like to eat,” Barkley said in a statement that reflects the tone and attitude of his commercial. “Like a lot of athletes, I’ve gained weight since I’ve retired. But, I don’t want to be a fat old man taking lots of pills. Weight Watchers is helping me change my lifestyle and learn how to make smarter eating choices anywhere I am.”

Barkley has been on the Weight Watchers Points Plus program since September and has lost 27 pounds on the plan, putting him at 309 pounds. He has a goal of weighing in at 280, according to the company.

Barkley’s TV ads will appear during sports programming on networks including ESPN and Turner Sports. Support includes print and such Internet destinations as Facebook and YouTube.

According to Bradshaw, “During my time as a professional football player and even after retirement, I stayed in great shape, but it wasn’t until all the injuries caught up with me and I couldn’t work out that the pounds started packing on. I found myself overweight and looking for the perfect plan to help me shed these packed pounds and get my health back.”

Bradshaw said he was “inspired by Dan Marino’s and coach Don Shula’s weight loss success on Nutrisystem and gave the program a try. Bottom line, Nutrisystem for Men is the go-to guy’s diet.”

Despite similar DNAs, there is a difference in the way they seek to reach consumers.

“Nutrisystem market[s] heavily to the male 25-54 age group by using football players, ESPN broadcasters and spending heavily on ESPN (advertising).” said David Schwab, the managing director of Octagon division First Call, which works with marketers and brands on who, how and when to use famous personalities in their campaigns. “Weight Watchers likes to use celebrities that generate strong publicity so that they can appeal to both men and women.”

Ultimately, the end result could be the same. “These are men’s men, Hall of Famers who are not worried where their next (healthy) meal is coming from,” said Meindl. “As endorsers of weight loss products they have the credibility and believability making it OK for men.”

While these celeb-athlete spokesmen may inspire others to loss weigh via food-centric programs, experts stress that fitness should be given as much, if not more, of a significant role.

The main reason: It’s hard not just to lose weight but to maintain that weight loss.

A new study on health, weight and fitness from the University of South Carolina’s Arnold School of Public Health in Columbia, conducted research on more than 14,300 adult males. The report said that, according to their findings, if someone maintains or improves their fitness level, even if their body weight does not change or increase,  they can can reduce their risk of death.