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 that participants were given a small breakfast and no replacement nutrients in their IV, then compelled to exercise, and, hence, went to lunch with an energy deficit.  Interestingly, they ate less than the other days, though, presumably, they ate to satisfaction – ad libitum.  It looked to me as though they were satisfied with less food and a smaller energy balance after exercise.  The narrative of the study seemed to indicate this too, even though it wasn’t a “finding” of its own.  Could that be true? 

In the caption to the Figure it reads:  “Midday meal did not compensate for the significantly lower energy balance in SED-R and EX trials (Fdf4,45 = 77.13; P < 0.0001), which remained uncorrected after the meal (Fdf4,45 = 10.17; P < 0.0001).” 

Huh?  Uncorrected why? 

I emailed Dr. Borer.  I asked whether that meant that the meal did not, in total, contain enough calories to compensate or whether the participants chose to eat less.  She clarified that they were allowed to eat to satisfaction and had plenty of food.  Then she said, “It looks like the exercisers (without extra calories infused into their veins) ate a bit less, but it was not statistically significant.”  (Italics mine.)  She went on to say, after some commentary  . . .  “They just lost or did not eat 400 to 500 Kcal.”  My jaw dropped reading that.  Unconsciously foregoing 400 to 500 kcal may be statistically insignificant, but my God!  AND, I’ll grant you, that over the course of a week or so, a standard-issue person will likely compensate for 400 to 500 kcal.  However, we as radical weight-loss maintainers are, ourselves, as I’ve said before, statistical outliers.  If 97 percent of people who lose weight regain it, then our results, and the behaviors we employ to produce those results, are so out-of-the-norm as to qualify us as statistically insignificant. Nothing about us is standard issue, whether we choose to be “inspirational” or cynical. So, my statistically insignificant maintainer buddies, how does this graph read to you?  To me it says exercise is not merely for energy balance, but suppresses the endocrine (which, according to these studies, is not necessarily leptin and insulin, since their rise and fall does not track consistently with appetite) that triggers our “eat impulses.”

Dr. Borer attached two articles to her email that she thought I might find meaningful. They are by MacLean, et. al.  You may note in the et. al. is Holly Wyatt, who we know here as the scientist who looks like Farrah, and is now associated with the National Weight Control Registry.  Also in the et. al. is James O. Hill, co-founder of the NWCR, which gives me pause.  I know he comes with the bias that behavior can and should be duplicated in service to radical weight-loss maintenance. I’m on heightened alert for the presences of this bias, and haven’t read the studies yet, but they look interesting, nevertheless.  Here are their titles, and links:

Regular exercise attenuates the metabolic drive to regain weight after long-term weight loss

Biology’s Response to Dieting: the Impetus for Weight Regain

Now, back to Dr. Borer and her work.  The concept of homeostasis has apparently haunted her.   She was troubled enough by it, in fact, to look at her own data with fresh eyes.  

We have struggled here at this blog with the idea of homeostasis.  Among its problems, it only works one way:  it will increase our appetites and slow down our movement to protect a higher weight.  On the other hand, when we all-too-easily gain weight (the Freshman 15, for example) it doesn’t blunt our appetites and speed us up to return us to our lower weight.  (Or at least not all of us.  It is exasperatingly inconsistent.)  Dr. Borer notes that some human and rat studies show increases in activity in subjects when weight loss is imposed on them (I wonder if that is their ancient “hunt and gather” wiring telling them to get busy and go find food) and decreases in activity when obesity is imposed (the body saying, “you may relax now; you’ve got stores”).

For Dr. Borer:  “The inconsistencies between the contemporary homeostatic concept of energy regulation and evidence implicating nonhomeostatic controls prompted us examine the role of leptin and insulin in the control of human meal-to-meal eating and appetite.”

Her original study did not find a tidy correlation between the rises and falls in leptin and insulin that would track with participants’ perceived appetites.  And instead of writing off the perceptions of her participants, she has proposed that insulin and leptin may function differently in our bodies than often supposed.  She discussed findings on circadian rhythms and hedonic circuitry that also influence our desire to eat (or not), in addition to homeostatic forces.  Her assertion: 

“Substantial evidence suggests that involvement of insulin and leptin in nonhomeostatic control of meal eating and physical activity is mediated through their actions on the brain substrates of reward.”

In other words, surges in insulin and leptin don’t communicate with us about our physical satiety; they may just shut down the mental reward party.  Specifically (Borerese):  “Low insulin and leptin levels enhance, whereas high insulin and leptin levels dampen, the rewarding value of stimulation of this circuit by suppressing the release of dopamine and related neurotransmitters.”  

This theory regarding insulin and leptin suggests to me one reason for the diverse adiposity of humans.  At Big Fat Blog we have discussed, from time to time, that some fat people do fit the stereotype – they eat to excess by many people’s sensibilities. Often, they’re “fat and jolly,” or could be but suppress that impulse, lest they get labeled as “bad” fatties, v. the “good” fatties who exercise ferociously and eat in moderation but still get fat.  This does seem unfair.  Maybe some people’s mental food reward parties are just better and last longer than others’.  Maybe they take enormous pleasure in food, for long periods of time; while other people simply don’t.  It is sad that our society, because of the “war on obesity,” has lost the ability to celebrate fat people who enjoy food, or simply accept them and treat them with basic dignity.

But I digress.  Borer’s study seems to reinforce the nonhomeostatic role for leptin and insulin on a meal-to-meal basis.  This doesn’t mean that homeostasis doesn’t exist (if defined as our bodies’ long-range compulsion to protect or return to our highest established weight) nor does it mean that leptin and insulin don’t trigger homeostatic forces, but they do so through a relationship with the brain’s reward system, not by regulating physical satiety, meal by meal over the course of a day.

I have talked an awful lot today, and am just going to force myself to stop, even though I’d like to talk about exercise more.  Again, go up and look at Figure 2 and tell me what you think.  Or the findings.  Those are interesting fodder for discussion too.  The floor is open.

  1. That’s interesting! My observation that, for me, if I start the day in calorie “deficit” and time eating and exercise to keep me in slight deficit throughout the day, I feel comfortable eating less, would tend to be supported by this.

    Being able to “forget to eat” 400 calories is HUGE for a maintainer that burns at max 2600-2700/day.

    • That was my thought too, Cynthia. I balance at a kcal intake of 1,600 – 2,000 (and assume that my exercise plus NEAT burns it) so it seems even bigger.

  2. Is there a group that eats a very small breakfast but does not exercise? Because I am definitely in a calorie deficit by lunch, but that is just because I’m up for maybe an hour before eating breakfast, walk 20 min to work, eat about 200 calories for breakfast, and still have 4 hours between then and lunch. It might be the calorie deficit rather than the exercise per se. (I am the maintainer who does not exercise.)

    Also, unless I am misreading the graphs, it appears that at the midday meal the people in the 4th column only ate about 200 kJ less than the next lowest group, which would be 47 kcal less. Is it possible the 400-500 number she cited was either in kJ rather than kcal or after including the calorie deficit that the people were in before lunch? Because some people can definitely eat 600+ kcal for breakfast.

    Anyway, eating about 50 kcal less for lunch after a small breakfast sounds about right to me, just due to my stomach being not stretched out from having had a big breakfast.

    • The group that eats the small breakfast and then doesn’t exercise is column 1. It’s the second most beneficial in terms of calorie deficit. (I wince to think my size acceptance friends are reading me think like this. Sigh.)

      Though, gotta acknowledge, a twenty-minute walk is something. Not enormous (I’m sure you try not to work up a sweat before work) but something. And I assume you walk home too. That means you get 40 minutes of low-intensity daily exercise. That’s more than many sedentary people, but, yeah, you aren’t strapping on the weights and working out like me. And it’s virtually nothing compared to the verging-on-barfing that you described doing in the past. You’re perhaps running your own n = 1 experiment that is a compromise between the column 1 and column 4 group. FWIW, I don’t put much stock in the stretched-out stomach notion. I think it’s endocrine. You’re not triggering something. Or at least that’s my thought.

      With regard to the 400 kcal deficit: That represents the 550 kcal deficit from exercise, a negative number, added to their ad libitum lunch intake, a positive number that is only slightly lower than the other columns resulting in the bottom graph displaying what would appear to me as a significantly smaller net.

  3. Bottom line me here. Does this mean that my relatively new habit of morning exercise is a good thing? Now that I think about it, I always expect that I will crash or be REALLY hungry after a long morning walk. But I rarely am. I can usually make it from breakfast all the way to an early lunch without needing a snack.

    • I think this does bode well for your new routine, Debby. Your leptin surge from breakfast plus a little leptin surge from exercise is carrying you a good long time.

  4. Endocrine isn’t a noun. It’s endocrine system, or endocrinology.

    • Interesting, Maria. Thanks for trying to help me. Language is crucial, and I don’t like misusing it.

      Here’s the definition at the free on-line dictionary, and it does list endocrine secondarily as a noun, and as I have used it. So does on-line Webster’s, but I had to wait through an advertisement before it revealed the second definition. I didn’t look at others, but that was enough to show me that it’s accepted in common useage. That said, it wouldn’t surprise me to learn it’s a recent development, brought about by annoying nonprofessionals like me co-opting the word.

      For what it is worth, It drives me nuts to read “female” and “male” used as nouns. In journalism school I was taught that they are adjectives. Man and woman are the nouns, and they are simple and elegant. There’s a place for the nouns “lady” and “gentleman” too. I don’t know that there is a substitute for endocrine the way I romanitcally use it. Endocrine system, for example, is much bigger than what I often mean. “Endocrine system” to me is a big tower of Bable, and often when I talk about feeling my endocrine, I’m trying to parse one or two of the different languages from the tower. I’m trying to hear/feel the dance of aghouti-related protein with PeptideYY, for example, and separate that dance from the beat of the thyroid, which may be impossible. Or not.

      Endocrinology is its own word: the study of endocrine.

      While I’m trying to study endocrine (as it relates to my body, personally), it’s very different for me. I’m not a scientist. I adore scientists, but I don’t pretend to be one. I’m a maintainer. I lost 68 pounds (and assumed, from cultural mythology, that I would just keep it off by committing to some zippy lifestyle). Then I started reading science. That led to a big “Oh sh*t!” moment. Actually, a series of those moments. And anger, confusion, fear. Finally, some resolve. I have started battling to create fresh language that will describe, for my own benefit (and with the establishment of this blog, the benefit of anyone who wants to join me), what maintenance is. Our Biggest Loser culture fails us. Maintenance is NOT some lifestyle we adopt despite our endocrine system, or after we have overcome our psycological demons, or when we realize “it’s more than a diet; it’s a lifestyle” (like that’s some extraordinary revelation).

      Maintenance can be a slog. Maintenance can be a routine. Maintenance can be zippy some days. Maintenance is a state of consciousness. Sometimes it annoys us; other times it just is. Maintenance is always present with us maintainers. Like our endocrine. And I mean that in a broad, romantic way. If I said, “like our endocrine system,” that would evoke a different, more tangible image.

      In any event, now that you’ve said that, when I CAN use more precise language, I will. (Notice in the fifth paragraph, I could use “endocrine system” without hurting my meaning.)

  5. I’ve always thought that exercise sharpens my hunger and satiety cues. If I’ve been trying to restrict portions, then exercise will make it harder for me to do so. If I’ve been eating as much as I want (which is usually the case), then it can make me more sensitive to when I’m finished.

    When I was 30 pounds below my maximum weight for eight years, it was completely based on exercise and on eating sensibly; very rarely having a large restaurant meal or takeout, for example, and avoiding hedonistically (is that a word?) eating more than I was really hungry for. It wasn’t in any way an “always hungry” level of restriction and at the time, I didn’t think of it as restricted eating at all. And the exercise I did was a 20 minute walk to work and back every day and 3 or 4 exercise classes a week. Nothing painful, unpleasant or inconvenient there, either.

    Of course, my BMI was still over 30. If I’d been concentrating on getting my weight down to a doctor-approved level rather than on having healthy habits, then I know damn well I’d had to have been doing what you do Debra, or something more extreme.

    • “It wasn’t in any wan an “always hungry” level of restriction. . .” See, this is where our language fails us. We really don’t have the words that describe it. I’m not “always hungry,” but I am always different now. And sometimes it’s distracting. And sometimes it’s not. Sometimes it just is.

      What I understand, that Biggest Loser culture does not, is that this state of difference is disconcerting enough that most people choose not to live in it, or just cannot function efficiently in it.

      Science could help us by describing what’s happening inside during the process of weight loss, maintenance and regain. Person B has X endocrine profile. She loses weight, and as she does her endocrine profile starts to change. She reaches Y endocrine profile and coasts for a while, because it’s challenging but not impossible. (It’s so predictable. She says the words, “If I can do it anyone can.”) But then her chemicals go more out of balance and she reaches Z endocrine profile. It DOES NOT create a state of “always hungry.” And yet it’s “different” enough to compel/impel her to eat to recover her lost weight. She returns to X endocrine profile (or not?). Science owes us this explanation. (Someone needs to ask me for a vial of blood.)

      People feel so guilty about regain precisely because they aren’t “always hungry,” and yet they can’t seem to keep from eating to recover their lost weight. And when Biggest Loser culture tells them they are “bad,” they accept it. I want science to tell us it’s not moral, it’s chemical. It’s endocrine.

  6. Actually, I don’t eat that differently now. What’s changed is that I’m not as organized and disciplined about physical activity. I haven’t formed a new routine after the hip replacement I had two years ago, although I walk a mile or more several times a week and I go to an occasional Zumba class. And oh, okay. I’ve relaxed my “healthy eating” standards a bit too. The Indian takeout here is phenomenal, and I’m doing pub food/takeout more often than I used to. But actually I’m feeling pretty good, and I’m getting to where I could handle the same type of activity level I had before my hip started to act up. So, maybe I’ll go on another health kick and maybe if I do I’ll be a little lighter again. Or not. Whether I weigh a little under 200 pounds or a little over isn’t that big a deal to me, my body doesn’t seem inclined to weigh more than 220 or less than 180, and I seem to be healthy and feel reasonably good anywhere in that range.

  7. Yup. I think we’ve said it before. You’ve found a range. I would bet your endocrine profile at 180 is little different from that at 220. Within that range, it’s behavior alone that determines your weight. BUT if you were to push below that 180, you’d join my club. It would become more difficult. My club, honestly speaking, probably isn’t worth it. It’s been romanitcized, and sometimes I feel like a schmuck for not gracefully accepting my thin privilege and shutting my yap. There is some pressure to do that too, you know.

  8. I’m really glad that you’re not gracefully accepting thin privilege and shutting your yap – and I’ve seen the pressure for you to do it in earlier posts’ comment threads.

    You’re providing a valuable perspective that I haven’t seen anywhere else, and your blog is also a place where fat acceptance activists can discuss things that toe the line between HAES and deliberate weight control without violating safe space. Frankly, I just don’t usually discuss this stuff because I can’t stomach the weight-negative parts of the internet at all.

    To be honest, I’m relieved that the hip problems didn’t throw me out of my set range; just took me back up to the top of it for a short time. To me, this is evidence that my approach to HAES, even though it can result in me weighing a bit less, doesn’t shift my set range upward. And honestly, I’d rather not be heavier than I am. It makes everything more inconvenient and I’d like to hang onto whatever doesn’t-look-all-that-fat privilege I may have.

    My body resists weigh loss at 180 and resists weight gain at 220, so yeah. It’s probably a different endocrine profile. I slide around pretty freely between those two weights, though. I can easily gain or lose 10 or 15 pounds without changing much. It’s almost embarrassing how easily my weigh changes. I even look noticeably fatter at certain times of month. Back when I used to weigh myself, I’d sometimes see a five pound weight gain in response to a big meal.

  9. Being “very tiny” (as the cab driver who’s driven me from the airport to various assignments in Sudbury calls me), I find that I must literally feel hungry every day to lose weight and to keep it off. The minute I don’t feel hungry, the weight comes back on. The typical weight loss crowd would say that it’s because I’ve returned to my gorging ways. Except that there’s never been anything particularly bad either about the quantity or the quality of what I eat. I just seem to be at the weight where my body feels most at home. My head, on the other hand, would feel most at home about 30 pounds less. My body is definitely winning on this one!

    • The body is nearly always the superior player in this funny game, NewMe. Frustrates me every time it wins back another pound. Creep, creep. It’s hard to keep the brain sane and the body well fed in this odd, complicated culture of ours.

  10. It sounds like those 400-500 calories are not “foregone” through not eating or appetite suppression, though. They are simply burned by the exercise. It looks like exercise only suppresses appetite by about 50 calories, which would be pretty negligible even if the finding were significant.

  11. View it through whatever lens works for you, Amy. I gotta tell you, I look at that bottom graph, the net, and I get more excited than you do looking at the middle graph. Now, whether this net reduction (by comparison to the other columns) is lasting — whether at day’s end or week’s end there is a net reduction for these moderate exercisers? Who knows. It’s interesting, and more substantive and useful than a beauty pageant winner telling me that the American Dream is real.

  12. The body is nearly always the superior player in this funny game, NewMe. Frustrates me every time it wins back another pound. Creep, creep. It’s hard to keep the brain sane and the body well fed in this odd, complicated culture of ours.

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