I wrote an article for TechNet on Putting IT on a Diet.

MSNBC provides data that show people doubled their weight savings when they used a food diary.

Writing down every morsel doubles weight loss
Dieters who kept daily food diaries were more successful, new study says
By Steve Mitchell
MSNBC contributor
updated 1 hour, 47 minutes ago
In the struggle to lose weight, picking up a pen might be just as useful as putting down the fork.
That’s according to a new study that found that people who kept daily food diaries lost twice as much weight or more as those who didn’t keep a tally of their meals.
Nearly 1,700 Kaiser Permanente study participants agreed to exercise and adopt a healthy diet, but those who took the extra step of keeping track of what they consumed got something of a booster charge in their weight loss.

A good tip to keep in mind when putting your own Green IT/Data Center program in place. If you want to automate your diary data collection you should look at a tool like http://www.osisoft.com/Industries/Information%20Technology/.

Fluctuating power quality and power loss in equipment
Lack of information to correlate IT load and power consumed by IT assets
Inefficient cooling system operations
Lack of information to correlate server IT load and cost of power
Inadequate performance monitoring and condition-based maintenance of equipment
Difficulty in performing capacity planning in terms of power, cooling and IT resources