Nature vs nurture and set points?

tigerblue

I posted this comment in the main forums, and one of my "pals" who is also a member of this group, suggested posting here for a more "educated and informed" response. So here it is. . .

I'm just wondering what everyone thinks--do our bodies have an easily maintained "set point"? (Which can easily be maintained by eating intuitively based on our appetite?) And can it be changed? And How does body type figure into that?

Here is where I am coming from. I have been visiting my sister, who looks in many ways very similar to me. But although we are both fairly small, we definitely have different body types. She is much leaner and a bit more muscular than I. She tends to have the long slim body type, where I am curvy even when at my lowest weight. (Long is relative--neither of us is tall although she is taller than I am). She has to worry about losing too much weight. I have to worry about gaining weight. She doesn't get hungry. I'm always hungry, if I am trying to maintain a healthy body weight (if I give in to my appetite, I end up about 15-20 lbs overweight).

Now, obviously, she is a bit smaller than me mostly because she eats less than me. But my question has to do with what drives the eating--do we have a natural appetitie that takes our bodies to a natural "happy weight"? And if so, can that "happy weight" number be changed or are we always going to be fighting against ourselves?

So how much science is behind this? Any? Are we destined by our genetic makeup to have certain weight tendencies? Or is it learned behavior?

I am really not looking for answers to how to manage my weight with this. I am also not looking at differences in metabolism. This is really all about discussing appetite regulation. And it is just for the purpose of discussion and sharing of experiences.

For the record, I don't believe that we are completely predetermined to be a certain size, but I do believe we all have certain tendencies that we have to work around.

Regardless, in the end there is always a choice about your behavior and eating.

SideSteel

This is a great question.

I'm not going to have an answer that is backed with research that I'm aware of. I'm going to provide you with opinion and some reading.

I think (and I believe there's a paper or two discussing this) we have differences in responses to overfeeding and underfeeding with regards to the effect it has on non exercise activity thermogenesis. So for example if you take a group of people and overfeed them by a given amount, you'll see varying effects on rate of weight gain due to some of the people responding by naturally upregulating fidgeting and movement in general to compensate for the additional calories coming in. This is one proposed mechanism to explain differences in effects on similar surpluses (and presumably deficits).

I'm not aware of research that seeks to explain set point and if it exists (I've never actually looked) it's probably also a theoretical topic but something worth exploring.

Our habits that we form around food and activity lead us to weigh a given amount. But if it were as simple as just "eating less and moving more" then weight loss would probably be a whole lot easier to achieve and maintain. And there are a number of things in place to prevent weight maintenance such as an increase in hunger signaling and a reduction in energy expenditure when fat is lost and calories are restricted.

While this doesn't address set point theory directly I would check out some of Stephan Guyenet's work. He has a couple of great pieces of information (one I recall is a youtube video that discusses the various mechanisms that resist weight loss and it's quite fascinating).

Another piece you can find here from Lyle:
http://www.bodyrecomposition.com/fat-loss/set-points-settling-points-and-bodyweight-regulation-part-1.html/

Finally, I think this is a good question for Eric Helms, and time permitting I'll ask him when we finally interview him.

tigerblue

Your link is right on point with what I have been mulling over in my mind. Next question would be why do people have different set points, or whatever you might call them? Why would everyone's set point not be "healthy weight"?

jenglish712

I'm going to jump in here a wax philosophic, feel free to ignore me.

I'm not sure people's "set point" may not be relatively healthy for them. I have known some thickly built guys who looked a little unhealthy but were athletic, whooped my butt on a distance hike, and had better results on their bloodwork than I did when I was thin and in poor shape. Healthy is something environment naturally selects for... but is what's a healthy human build on the Serengetti may not be selected for (via successful offspring) in the arctic circle.

tigerblue

jenglish712 wrote: »

I'm going to jump in here a wax philosophic, feel free to ignore me.

I'm not sure people's "set point" may not be relatively healthy for them. I have known some thickly built guys who looked a little unhealthy but were athletic, whooped my butt on a distance hike, and had better results on their bloodwork than I did when I was thin and in poor shape. Healthy is something environment naturally selects for... but is what's a healthy human build on the Serengetti may not be selected for (via successful offspring) in the arctic circle.

Hmmmm. Interesting! I've never thought about that!