Def Jam president Jay-Z, 36, lost 15 pounds thanks to a diet his girlfriend Beyonce, 24, put him on. He is said to be feasting on high protein meals and lots of vegetables and to have given up candy. Jay-Z’s weight loss has people speculating that the famous couple may be planning to get married:

Beyonce has been focussing on her figure and probably encouraged Jay-Z to lose weight as a result. We don’t think it means that they’re preparing for marriage.

Beyonce is not one to give nutritional advice. She said that she lost over 20 pounds for her Dreamgirls role by fasting and drinking spicy water for over a week, and that she gained some of the weight back by eating a lot of fried food.

The two have hit a rought patch lately, with reports that they were fighting at a playoff game, and that Beyonce is jealous of Jigga’s very friendly working relationship with sexy singer Rhianna.

Jay-Z and Beyonce are pairing up again in the studio. They are collaborating on Beyonce’s new album, to be released on her 25th birthday, September 4th. The pair had a big hit with Beyonce’s 2003’s single “Crazy in Love.”

Jay-Z is pictured with Bill Gates, above [via] and at the 2006 Music Visionary of the Year Award breakfast on 5/24 with Daniel Glass and Antonio L.A. Reid. He is also shown on 5/22 at a NY Listening Session. He looks great.