There’s a great series on HBO right now called The Weight of the Nation (iTunes, Twitter) that I highly recommend. Apple has (at this moment) 3 free episodes from the series in iTunes, so there’s no excuse for not watching them.
I just watched the second episode, which looks at why it’s so hard to keep weight off after you lose it, and goes into the role leptin plays (something I’ve blogged about before). One of the two doctors in the episode was part of the team that discovered leptin and its role in the body in 1994.
What the researchers found is that the body has a sort of point of stasis – a weight at which it naturally balances. It’s a function of lifestyle and biology. When you lose weight from this level, the body goes into a bit of a protection mode, slowing metabolism as it’s getting less fuel (and/or keeping less if you up your exercise) to compensate. They gave a really useful example. Two women of equal height, weight and build. One is naturally that way while the other lost some weight to be that way. If they eat the same type and amount of food, the one who was heavier will start to gain the weight back. So, even though they look the same, they can’t live the same. The episode then follows a research participant who loses 40 pounds, and needs to eat 300 fewer calories per day to maintain her new weight to make up for her body’s shift in burning.
I may be wrong on the exact biology since I’m not a doctor, but the gist of it is that leptin production is reduced (or perhaps the signals it sends to the brain are reduced), so the brain slows down processing fat / calories. You can do something about it to maintain – either restrict calories like the test subject, or find ways to spike your leptin. Ideally, you do a bit of both.
This is precisely why the Slow Carb Diet with a Cheat Day works so well. You go into a restriction of ‘bad’ calories (I hate that term, but you get what I mean here) while using cheat days to spike your leptin production/signaling to the brain so it doesn’t slow metabolism (or not as much).
The only thing it has me thinking is that my plan to ease off the SCD at the 1 year mark really needs to be tempered and controlled. I don’t think I want to be off it completely as I’ve learned a lot of good, healthy habits (e.g. eating WAY more greens, avoiding processed/refined sugar, reduction/avoidance of high-man-made-chemical foods, etc), but to maintain, I also won’t really be able to go back to the Standard American Diet (it’s such poetic justice that this abbreviates to ‘SAD’).
While that may sound terrible to lots of people, but it really isn’t to me. Because I look at my diet as a holistic view of what I eat every day, and not some short term, unnatural, unsustainable crash course to look good for an event or fit in some clothes I’ve had tucked away in my closet, this is perfectly fine. I’ve not been counting down the days until I could eat pizza every day, or when I could stock the pantry with Oreos and Nutter Butters. I don’t care about that anymore. I feel great, my food makes me feel great (for a change), and I love the message I’m sending to my young son about being healthy. It’s all in framing and attitude.
It’s really interesting, and I encourage you to watch this free episode. It’s a great way to help you enlighten.your.body.