Posts Tagged ‘Exercise’

What Katarina Borer Found: Good News for Maintainers?

In Weight-Loss Maintenance on July 8, 2011 at 12:52 pm

Before I say another word, my conscience tells me to add a BIG trigger caution here.  If you are a size acceptance proponent and are feeling the least bit susceptible to the call of the weight-loss diet fairy, skip today’s post.  If you’re feeling brave, however, I’d love your response as well as that of my maintainer friends.

In my last post I explained Katarina Borer’s methodology for comparing the effects of food intake and exercise on appetite and on certain endocrine secretions.  Dr. Barry Braun describes it as “a multicondition crossover design to cleverly disentangle the relationships between energy imbalance, exercise, energy intake, putatative energy-regulating hormones and perceived appetite.”  Yup.   That’s what it was.  Now, let’s see whether I can explain in plain English what happened and what was correlated and what was not.

In her first study, Appetite Responds to Changes in Meal Content, Whereas Ghrelin, Leptin and Insulin Track changes in energy Availability, Dr. Borer found:  

  1. Human appetite is influenced by the passage of food through the mouth and gastrointestinal tract.  When food went through the mouth, it triggered GIP, a gut peptide that is activated and serves as a marker for GI activity but seemingly has no affecting qualities of its own.  This peptide rose and fell in concert with participants’ reported appetites. 
  2. Participants’ appetites responded to the size of meals that came in through the mouth, but were insensitive to calorie replacements (or saline placebos) that came through an IV.  Moreover, exercise did not increase appetite, but marginally suppressed it.  This led her to state that “between-meal increases in circulating nutrient load and exercise energy expenditure are not under homeostatic feedback control.”
  3. Ghrelin, leptin and insulin respond in slightly different ways to changes in energy availability, but had no influence on participants’ appetites.  Whoa.  Interesting, yes?  Dr. Borer thought so too.

The graph array that interested me most, as a maintainer, however, was Figure 2 (in the second study it was reposted as Figure 4).  I was surprised, in fact, that it was not included as a “finding” in the Discussion section.

It looks fuzzy in my preview, but I was able to click on it to get a blown-up view that was very clear.  Column 4 describes the trial day Read the rest of this entry »


Katarina Borer: My First Impressions of her Recent Work

In Weight-Loss Maintenance on June 30, 2011 at 3:04 pm

It’s taking time, but I am working my way through a study, an article and a commentary surrounding some recent work by Dr. Katarina Borer and colleagues on endocrine, appetite and exercise.  

I believe I mentioned that Dr. Borer contacted me in response to my Open Letter to Weight Management Scientists.  I may have also mentioned that she said my postings were, ahem, interesting and remarkably well informed for a person who is not actively engaged in research. I am digging deep to find my inner objective scientist who would not be moved by such flattery.

I am working my way through these pieces simultaneously because they are based on the same trials, but they present two sets of conclusions.  The first set may be found in the study itself, entitled Appetite Responds to Changes in Meal Content, Whereas Ghrelin, Leptin and Insulin Track Changes in Energy Availability and was published in July 2009 in The Journal of Clinical Endocrinology and Metabolism.  To give credit where due, her co-scientists are Elizabeth Wuorinen, Kimberly Ku and Charles Burant, not that those names are meaningful to me.  Actually, very few of the names in this line of research are meaningful to me . . . yet. 

The way I read a study or article is to turn first to the footnotes to get an idea of the bricks that form the foundation for the work or thought at hand.  I screen through the lens of my own evaluation system to determine what biases are present.  Mostly, in the past, I have read studies that are solely obesity focused, and, whether they admit to it or not, most scientists in this area come with one or more biases.  Some feel that obesity is a medical and social ill that must be reversed or cured, and their research is colored by that view – it may prevent them from seeing certain options.  Some of these scientists have accepted support from commercial interests – diet companies, foundations associated with pharmaceutical companies, and the like, and that makes their work horribly suspect.  Others who publish in this realm are testing the “Health at Every Size” paradigm, or, more accurately, are Hell bent on proving the efficacy of that model, and that limits their view.  In any event, I often can see a study or article’s self-imposed limitations in its footnotes.  Certain names pop up together over and over, and they indicate a point of view.

I don’t have a grasp of such biases and limitations in the world of endocrine and exercise.  In this world, obesity and weight loss are sometimes the focus, but often just confounding factors. With the exception of Cummings et. al., who produced a Ghrelin study that I happened upon by accident, I recognized no one.  I am, therefore, trusting that these are all sterling people, and none is a “scientist for sale.”  Feel free to correct me if I’m wrong. Read the rest of this entry »

Back When I was “Inspirational”

In Weight-Loss Maintenance on April 19, 2011 at 1:36 pm

Yesterday, Barbara Berkeley posted an essay on the value of embracing exercise.  In it she encourages all of us (and inspires those of willing spirit) to keep trying to fall in love with physical exertion.  Good advice.  Her drug of choice is tennis.  Once upon a time, mine was running. 

Barbara’s essay prompted me to do a word search for “running” in some pages I’d written.  I was hoping for something inspirational that I could update for this blog.  Instead, I happened upon a discomfiting draft of an essay that dated to 2006 or thereabouts.   The context tells me it was a time when Oprah was trim and bragging about doing 300 sit-ups a day.  I was gloriously in love with running, and never suspected my joints would put an end to that affair.  I didn’t know whether I actually qualified as “high” when I ran, but I knew that I loved to run (or, more accurately based on speed, “jog”), I craved it, and often while running I lost track of time and place.  I ended up back at home at a time that would indicate I’d trod my usual course, but not remembering specifics.  Here’s what I wrote about the process: 

When I jog, I find myself writing essays or creating fiction plots that I will later take down, mumbling long passages of dialog and playing multiple characters.  Sometimes I mentally stage and win arguments with PTA moms who disagree with my fundraising ideas, or I refurbish my house.  Some days I engage in conversations, musical duets or more intimate liaisons with movie stars or musicians. (On rare occasions I think about liaisons with my husband.)  I discuss the future of the planet with scientists, politicians or other newsmakers.  I negotiate peace accords in troubled countries where I don’t speak the language, but I charm my fellow delegates by feeding them their favorite native desserts prepared by my expert chef.  I talk through my interpreter of a peaceful co-existence, and we all strategize about reducing the world’s horrible stockpile of weapons one by one.  Then I exchange my bulletproof brassiere for a standard Maidenform and go talk to Oprah about it on her show.  (I know Jim Lehrer would be more appropriate, but this is my fantasy.) Read the rest of this entry »