The research in question was done on rats, and it's always tricky to extrapolate such work to humans; and there are serious ethical issues with killing rats to find our why humans become such pigs when they eat cows. But the phenomenon in question is expected to apply to humans as well.
The researchers also performed in vitro experiments where they directly observed palmitic acid (a common saturated fatty acid) inhibiting the signaling of nerve cells exposed to insulin.
On the other hand, oleic acid, a monounsaturated fatty acid, did not produce this result.
What evolutionary mechanism might produce such a result, that too much fat in the system actually tells the body to increase rather than decrease food uptake? Here's what one leptin expert quoted in the SciAm article says:
When you combine Glenn Beck, the Tea Party, and the recent bizarre historical revisionist attempt of the right wing to claim the Civil Rights movement as a conservative one, you know there's going to be some laughs. Beckites and tea baggers from all over the country are heading to D.C. for a rally on the anniversary of King's "I Have a Dream" speech. The only problem is, D.C. is full of, you know, black people; so a Maine Tea Party group has offered some interesting advice on how to stick to "safe" areas of the city, with such helpful tips as staying off of the entire Green and Yellow Metro lines -- keeping you safely away from such dangerous areas as the National Archives, Howard University, the University of Maryland College Park, and the U Street corridor.
When I head down to D.C., by the way, I usually drive to Greenbelt and take the Green Line downtown. Guess I've just got more guts than these teabaggers. (Of course, I am from Harm City -- okay, the suburbs of Harm City, but still -- so I don't scare easy.)
If you're a bit of a math geek, you may know Newton's method for finding the square root of a number. It's fairly simple; you start with a guess, divide the number by the guess, and take the average of the quotient and the guess as a new guess. (Remember, to take the average of two numbers, we add them and divide by two.) Lather, rinse, repeat, and you'll get closer and closer the the root.
For example, let's say I want to find the square root of 110 -- which is going to be close to 10, but let's say I don't know that, so I pick 55 as my guess. 110/55=2, so my next guess is (55+2)/2=28.5. Getting closer already.
110/28.5 is 3.8596 (we'll say four places is enough), so our next guess is (28.5+3.8596)/2=16.1798.
110/16.1798 is 6.7986, so our next guess is (16.1798+6.7986)/2=11.4892.
110/11.4892 is 9.5742, so our next guess is (11.4892+9.5742)/2=10.5317.
Let's do one more round: 110/10.5317=10.4447, (10.5317+10.4447)/2=10.4882
You can see that we're getting close and closer to the real value, which is around 10.4881, and that we could repeat this over and over to get as close as we want.
That's pretty cool, but you can't easily use this to get a specific number of digits of accuracy in the result. Plus, you have to keep doing division. Yuck. I used a calculator (actually, bc, the Unix desktop calculator) above, but what if we were doing this by hand?
I've had this trace of memory stuck in the back of my head for about thirty years, that I once saw a method for computing square roots digit-by-digit, that looked something like long division. And finally, thanks to Google, I found it again!
