Mannatech also launched the OsoLean(TM) Challenge among its independent Associates, who will track their waist circumference in inches while using OsoLean(TM) powder, in conjunction with the OsoLean(TM) Plan and exercise, during an eight week period between Sept. 4 and Dec. 31, 2008.* A number of Mannatech executives have also joined the challenge, sparking some friendly competition with Associates...