Sleep Post Correction

An astute commenter pointed out that I misread the numbers in the paper on sleep and fat loss. I wrote that out of the total 3.0 kg lost, the high-sleep group lost 2.4 kg as fat, and the low-sleep group lost 1.4 kg of fat out of 2.9 kg total.

In fact, the high-sleep group lost 1.4 out of 2.9 kg as fat, and the low-sleep group lost 0.6 out of 3.0 kg as fat. So I got the numbers all mixed up. Sorry for the mistake. The main point of the post still stands though: sleep deprivation negatively influences body composition.

The correct numbers are even more interesting than the ones I made up. Even in the high-sleep group, nearly half the body weight lost by simple calorie restriction was lean mass. That doesn't make calorie restriction look very good!

In the sleep-deprived group, 80% of the weight lost by calorie restriction came out of lean mass. Ouch!

That illustrates one of the reasons why I'm skeptical of simple calorie restriction as a means of fat loss. When the body "wants" to be fat, it will sacrifice lean mass to preserve fat tissue. For example, the genetically obese Zucker rat cannot be starved thin. If you try to put it on a severe calorie-restricted diet, it will literally die fat because it will cannibalize its own lean mass (muscle, heart, brain, etc.) to spare the fat. That's an extreme example, but it illustrates the point.

The key is not only to balance energy intake with expenditure (which the brain does automatically when it's working correctly), but to allocate energy appropriately to lean and fat mass.

monday, monday

yep, it's definitely monday......
i was exhausted from traveling so i took a super long nap yesterday afternoon.  not such a good idea...i found myself staring at the clock at 2:00 AM...then i found taylor staring at me at 6:30.  coffee please.

*images courtesy of english muse, full house

And the Truthy Shall Set You Free

I've just read about a great project at Indiana called Truthy. (Here's a linky). The idea is simple: during the upcoming election, their system will detect smear campaigns on social networking sites in real time, and post some visualization of how the meme spreads over time. The idea is to try to prevent "astroturfing", which are well-organized political campaigns masquerading as grassroots efforts.

"The team will then generate diffusion network images that visitors to Truthy.indiana.edu can view as groups of nodes and edges that identify retweets, mentions, and the extent of the epidemic...

Menczer got the idea for the Truthy website after hearing researchers from Wellesley College speak earlier this year on their research analyzing a well-known Twitter bomb campaign conducted by the conservative group American Future Fund (AFF) against Martha Coakley, a democrat who lost the Massachusetts senatorial seat formerly held by the late Edward Kennedy. Republican challenger Scott Brown won the seat after AFF set up nine Twitter accounts in early morning hours prior to the election and then sent out 929 tweets in two hours before Twitter realized the information was spam. By then the messages had reached 60,000 people.

Menczer explained that because search engines now include Twitter trends in search results, an astroturfing campaign -- where the concerted efforts of special interests are disguised as a spontaneous grassroots movement -- that includes Twitter bombs can jack up how high a result shows up on Google even if the information is false...

'One of the concerns about social media is that people are being manipulated without realizing it because a meme can be given instant global popularity by a high search engine ranking, in turn perpetuating the falsehood,' Menczer said."

Definitely a clever approach to the problem, and if you're a twitter user, get involved!