Oprah Winfrey on stage during her An Evening With Oprah tour in Sydney, Australia. She will face off with Kirstie Alley as the newest spokeswoman in the weight-loss industry. 
Oprah Winfrey on stage during her An Evening With Oprah tour in Sydney, Australia. She will face off with Kirstie Alley as the newest spokeswoman in the weight-loss industry.  - 

Got a weight-loss resolution? The competition is on for your diet plan.

Just in time for New Year's, Weight Watchers aired the first TV spot of its campaign featuring former talk show host Oprah Winfrey last week. The launch of this campaign comes two months after the weight loss company announced its partnership with Winfrey.

Just two days later, Jenny Craig — a Weight Watchers competitor — also released a new TV ad featuring their on-again star Kirstie Alley.

When Winfrey announced that she would be partnering with Weight Watchers last October, the company’s stock price doubled overnight. The partnership gave Winfrey a seat on Weight Watchers’ board of directors as well as 10 percent of its shares. However, Winfrey will also be participating in the program and publicly sharing her weight-loss.

Just a few days after officially announcing the partnership, Winfrey went on the Ellen DeGeneres Show and announced that she lost 15 pounds between August and October.

Similarly, Kirstie Alley began publicly announcing her weight loss last January after being back on Jenny Craig for a few months.

Alley struck a deal with Jenny Craig when she returned to the company in April 2014 after leaving in 2007. While Alley was gone from the company, she developed Organic Liaison, a weight loss and supplement system. When she signed back on with Jenny Craig, the company bought Organic Liaison and began selling its products. 

Winfrey had a huge impact on Jenny Craig's sales back in 2005 when she had Alley on her show to talk about her weight loss. Jenny Craig put out a press release stating that phone inquiries about the weight loss program went up by 81 percent the next day.

Winfrey has yet to release any before and after pictures a la Kirstie Alley, but she has posted five videos on the OWN YouTube page to accompany the launch of her TV spot.