Lamar Odom looked healthier and was "in a very good mood" while celebrating his 34th birthday on Nov. 6 Credit: Sharpshooter Images/Splash News

Could turning another year older mean also turning over a new leaf? It certainly looks that way for Lamar Odom. The athlete, whose drug problems and rocky marriage to Khloe Kardashian have been well-documented in recent months, seemed to be in good spirits -- and good health -- when he stepped out in L.A. on Wednesday, Nov. 6, to celebrate his 34th birthday at Casa Vega.

"Lamar appeared to be in a very good mood throughout the meal," an onlooker tells Us Weekly of Odom, who was accompanied by two pals. "The group enjoyed margaritas and a variety of Casa Vega specialties, including tortilla soup, salads, and chicken enchiladas. Lamar himself ate an avocado salad."

Later in the day, the basketball player had dinner with pals at Boiling Crab, a popular spot in L.A.'s Koreatown. "He was celebrating with a small group of his close friends," a source tells Us. (Kardashian was not among the group, though another insider told Us the two originally planned to spend his birthday together at home.)

One night earlier, Odom took part in a different birthday celebration -- for his wife's mother, Kris Jenner, who turned 58 on Tuesday, Nov. 5. "Khloe and Lamar started talking again," a source told Us of the reality star, 29, and her estranged husband. "Over the last few days they started talking all the time. So [on Tuesday] she invited him to Kris' birthday party. He had a great time."

The source added that Odom has been taking better care of himself in recent weeks. "He's working out," the insider said, noting that the athlete had gained back about 20 pounds. "He's doing so much better."