Apparently drinking ice cold water is better than water that is at room temperature or is hot because it helps you burn more calories over time and essentially loose weight. I can confirm this has been stated repeatedly in multiple fitness magazines and by numerous weight loss gurus. The short reason is because your body has to warm up the water and in essence, burn the calories. Not suggesting you quit your gym membership, drink ice water and expect to be at status quo .. but just saying, it's a nice addition to the equation of working out and staying fit.
Chewing gum helps you lose weight. Not really... but like the Atkins Diet or the Subway Diet, it distracts you from eating those not so good things that would make you gain weight. Chewing gum is a way to avoid "mindless eating" and "mindless snacking." So if you combined chewing gum with junk food, you probably wouldn't see much of a difference... but if you chewed gum during the day to help decrease those munchy moments at 3 PM and eating because you're bored and not really hungry... then yes, it does help!