I just read an article on Sparkpeople.com by coach Nicole.
You hear all the time that to lose weight, you should track what you eat. Well, a 2008 study published in the American Journal of Preventive Medicine shows that keeping a “food diary” may double your weight loss efforts.
Researchers from Kaiser Permanente's Center for Health Research kept tabs on 1,685 overweight and obese adults (men and women), whose average weight was 212 pounds. The researchers encouraged participants to adhere to a reduced-calorie, DASH eating plan and asked them record their daily food intake and exercise minutes.
After 20 weeks, the average weight loss was 13 pounds per person. But researchers discovered something else; the more participants recorded what they ate, the more weight they lost in the end. Participants who did not keep a food diary lost about 9 pounds over the course of the study, while those who recorded their food intake six or more days per week lost 18 pounds—twice as much as those who didn't track any food!
As you might imagine she then goes on to tell about the nutrition tracking and fitness tracking at Sparkpeople.com I've spoken about Spark People in the past. I like them because I have access to them at work, on my phone, and basically anywhere I have Internet.
If you consider yourself a “Low Tech” person there are tools for that as well. If you don't really need something on your phone, but want a computerized tracker, I'm a big fan of Diet Power (and there are other resources as well).
The bottom line is you can't manage what you don't track.