What's the fast track to joining the ranks? Weight gain, particularly around the middle. An expanding waistline -- 35 inches or greater for women, 40 and over for men -- is a red flag. What can you do? Get active for at least 30 minutes a day, and shun foods high in saturated fat, white flour, and sugar: http://www.realage.com/news_features/tip.aspx?v=2&cid=16788.