Jessica Simpson is determined to lose more weight before her wedding.

The 33-year-old fashion mogul can't wait to marry her long-term fiancé, Eric Johnson, later this year and has already chosen her wedding dress.

In a new video to promote Weight Watchers' Simple Start program, Jessica, who first began following the diet plan after the birth of her 20-month-old daughter, Maxwell, in May 2012, said: ''The new year will definitely bring on the wedding bells, which is exciting ... I think it's about time.''

She added: ''Knowing that I have the wedding coming up is an incentive to stay on Weight Watchers, count my points and stay in the gym. I mean, when you see my dress, you'll know.''

Jessica, who also has a six-month-old son, Ace, said the diet has enabled her to ''completely re-focus and jump back on track'' with her health and fitness routine.

The blonde beauty, who was previously married to Nick Lachey from 2002 until 2006, hasn't made any ''grand'' New Year's resolutions but hopes to feel more body confident by the end of the year.

She said: ''I'm just trying to feel good in a pair of jeans and T-shirt. I can't wait to be able to feel just comfortable in my skin and know that I'm back to the person I've been before. I know this time I'm going to be so much stronger and so much more empowered, because I really earned it and I really got here, and took the steps to get here.''