New experimental evidence suggests why weight loss is not just calories in vs. calories out

Exercise induces the release of a hormone called irisin, which converts white fat into thermogenic (calorie-burning) brown fat, according to a new paper published Wednesday in Nature. They motivate the paper by saying, "Exercise has the capacity to improve metabolic status in obesity and type 2 diabetes, but the mechanisms are poorly understood. Importantly, exercise increases whole body energy expenditure beyond the calories used in the actual work performed." The paper begins to explain how it may be that exercise burns more calories than those in the actual work: that is, much research in the exercise science literature finds that anaerobic exercise (like strength training and high intensity intervals) burns calories for 48 hours afterwards. Perhaps this hormone begins to explain why.

Meanwhile everyone is still despairing slightly because of the NYT Magazine article suggesting that body weight setpoints make permanent weight loss very difficult for almost everyone. The article mostly quoted people who used very low calorie diets that induce starvation conditions and steady-state cardio. As many have noted, steady state cardio doesn't work. People who stay away from processed food and use high-intensity intervals and strength training may have more luck maintaining weight loss.

If I understand the biochemistry, other research already found that high-intensity exercise increases a related protein (e.g., as found in Tabata's paper, famous for his intervals). We already know that anaerobic exercises burn more calories for longer and result in greater fat loss and less muscle loss. This paper suggests why: anaerobic exercise may be most effective in converting white fat into brown fat.

I am disappointed not to see a practical conclusion --- more weight lifting and intervals, less low-calorie dieting --- in the NYT Magazine article. The message is still "just walk more", which clearly doesn't work, but people say it because it seems realistic and attainable (never mind that it's cold outside.) Instead "do something hard" might result in people pushing themselves more and gaining more of the benefits of exercise demonstrated in this paper. I wonder what state the science would have to be in before the messaging on exercise changes.

After reading the paper, I did 3 simple Tabata intervals, and from this paper now I know that the irisin makes it worthwhile.

Turning the tables on survey research

Just got off the phone with the Gallup pollster. I am one of their ~1000 person sample on their current health survey. When they asked my profession, I said that I was a survey researcher with health topics, and we both laughed. The coincidence was uncanny.

They ask important questions like approval of the president towards the beginning, along with the 1 question health assessment. They asked if I felt like I was treated with respect at work yesterday, a couple of other working conditions questions, income, and hours, personal stock market investment, as well as pessimism/optimism about economic growth, stock market, personal investment, employment, inflation. Also asked contextual questions such as satisfaction with neighborhood quality, safety, commute time to work.

The questions were of course cursory, such as giving only 2 or 3 option answers (satisfied or not, sometimes a neutral option). No questions had branching options, so every question was asked to every respondent, so only missing data should be due to people hanging up in the middle. The stock market investment quantity was phrased on a logarithmic scale, so above or below 10k, and then presumably other questions.

A couple of the questions were surprisingly badly worded, such as this double-barreled question, "Are you satisfied with the price and availability of fresh fruits and vegetables in your neighborhood?" Lots of availability but high prices here in Dupont Circle.

Short questions require respondents to define the categories themselves. For instance, they asked how many days out of the last 7 days have I exercised. I don't consider walking to be exercise, even walking for 5 miles. I haven't lifted weights or swam in the past week, so I said that I haven't exercised at all. In retrospect, probably it would have been more accurate to say a few days since I have walked more than 5 miles a few times this week.

Two questions I would have been interested in is whether people have a pet, since that goes with the health theme --- people with pets may have better health situation, and everyone likes to hear about pets. Another question is whether single people have a steady romantic relationship since "single" is a big and diverse category, and having a romantic partner could affect health and health outcomes. Of course I would have also liked to know whether people had sex recently, and whether they have safe sex, but I know that Gallup wouldn't do that.

Altogether, it was a 14 minute survey, and they are gathering a dataset that could furnish many papers on the connection between working conditions, attitudes towards the broader economy, political attitudes, and both mental and physical health. I wonder whether they will use the data for that purpose, or if they will just do the univariate and basic bivariate summaries. For sure, I'd appreciate the chance to analyze the data, if I could ever find the time.

Plenty of Syph: Fun public health campaign

The Health Department in Alberta, Canada, has a very cute syphilis awareness website: Plenty of Syph, like Plenty of Fish, but where all the singles have syphilis. Some of the pictures show a really nice oral primary syphilis chancre, a few have a secondary stage rash on a chest, and a few even have tertiary syphilis with gummas around the mouth. Very cute. (The mouth is unsurprisingly a relatively rare location for a syphilis sore, maybe just 10% of the time for primary syphilis. And not sure how common it is to get to tertiary syphilis.)

Condom ads

Condom ads around the world.

My favorites: 1970s style US porn, condoms dancing Bollywood style, and Kenyan Trust-brand condoms covering an umbrella. According to youtube, the Kenyan ad was banned.

Health communication in action

One of the standard anti-tobacco initiatives is to have graphic pictures and statements on cigarette packages to warn consumers. This dialogue shows one effect of the warnings.

Supermarket | London, UK

Me: “Can I help you, sir?”

Customer: “A packet of 20 Marlboro Lights, please.”

(I hand him the cigarettes.)

Customer: “Wait, I don’t want these ones.

Me: “Why? They’re Marlboro Lights. Did you change your mind?”

Customer: “No, I don’t want ones with this health warning about cigarettes causing impotency.”

Me: “Ok. Do you want ’smoking harms those around you,’ or ’smoking causes testicular cancer?’”

Customer: “Give me the ‘harms others’ ones.”

I'm not sure if that dialogue implies that the messages work or not.

Parody of the day: STD E-cards

A parody of the CDC's STD ecards.

Kids holding a large piece of paper.
"Giving bad news is sometimes really hard.
So I'm saying I gave you crabs with the help of this card."

A couple holds hands in the sunset on a beach.
"Thanks for the blow job.
Sorry about the herpes!"

Man covering his genitals.
"I've been experiencing some genital burn.
So I got tested and now it's your turn."
Not a bad message since some STDs are more likely to be symptomatic in men than in women.

Framing abstinence

People see issues differently depending on how they are framed.
This article looks at framing in the abstinence debate, specifically how using abstinence as the subject of a sentence instead of adolescents takes away adolescents' agency. That sounds abstruse, but it's an important difference both for advocates and sex educators (including abstinence educators.)

That is, saying "Abstinence is the only way to 100% prevent STDs and pregnancy." puts abstinence as the main idea, rather than adolescents, and makes the statement needlessly abstract. Adolescents thinking about having sex themselves would probably not feel any personal identification with that statement even while accepting the statement logically as a correct proposition.

Likewise, they don't use this example, but I think it applies equally: statements of "should" such as "Adolescents should wait to have sex." also take agency away and simultaneously add moralism, which is easy to tune out.

The article proposes using language that put adolescents back in the agency role, "Waiting to have sex..." or "Deciding not to have sex..." I like the statement with deciding best because it emphasizes the choice aspect.

I am not sure that framing would change efficacy of a curriculum, but the qualitative research from a couple months ago about adolescents' sexual decisions does indicate that the first two phrasings are probably ineffective, so it wouldn't hurt to try.

And there is no reason the abstinence movement couldn't adopt this wording. Everyone knows that adolescents have agency over their sexuality --- at the end of the abstinence program, they will be making decisions, not passively following rules. Adolescents who intend to be abstinent need to make decisions about intimacy, and in fact their decisions are more difficult if they want to be effective. Decisions have to include complete and accurate information which requires teaching birth control accurately.

There are certainly some sex-positive books written for young evangelical adults that emphasize their agency; one even says that sexuality is part of every social interaction ("Soul Virgins" written by two evangelical sex therapists, reviewed here earlier). I haven't seen any sex-positive literature for teenagers, but that doesn't mean it doesn't exist. Many of the adolescent curricula that I have seen do talk about sexuality as a contaminating external force, and that's just not productive.

The abstinence movement has other models for sexuality, such as sexuality as altering relationship development, that while negative don't mark sexuality as bad, but just as out of place in an adolescent relationship, and do concur with the mainstream adolescent research. So many of my colleagues begin papers by citing the statistic that most adolescents who have had sex wish they'd waited and that younger people are more vulnerable to STDs. (This American Life even has a segment about how couples use sweet talk to avoid being in the moment and developing their relationship. And last night the Big Bang Theory featured a girlfriend using sex to avoid uncomfortable conversation.)

These models of sexuality require discussions about how to develop healthy and meaningful romantic relationships. That's more difficult to teach than moralism and threats, but has some chance of being effective.

My favorite safer sex pamphlet

I pick up safer sex pamphlets wherever I find them, and so far my favorite is the Fenway Health Center's pamphlet. It gives a much broader range of sexual activities than any I've seen, and lists exactly which STDs are transmissible by them, and which STDs are transmitted by skin-to-skin contact so cannot be protected against by condoms.

A real problem in sex ed is how to talk about the skin-to-skin contact STDs. Sometimes they don't get mentioned except in an oblique way such as "The safest sex is no sex at all. Condoms cannot make you 100% safe." which can be read by the optimistic as implying 90% protection against all diseases. (In the abstinence-only literature, it's phrased as "Condoms can leave you vulnerable to many horrible diseases." which sounds like condoms are no good at all.) I like that this pamphlet treats STDs as individual entities each with their own transmission risks, rather than over-simplifying them.

They do not mention which STDs are commonly tested for in different clinical settings and which tests may need to be specially requested, which is an unfortunate gap because testing practices vary and many people speak of STDs as something tested for as if there were just one test for all known STDs when some STDs aren't tested for at all (e.g., as far as I know, no one screens men for HPV.)

Short abstinence updates

Catching up on some of the abstinence news while I was away:

1. A WSJ article tells of a teen vampire series with a large and burgeoning readership enraptured with the characters' intense restrained abstinent romance. The WSJ review of the actual book, however, is skeptical: "The most devoted readers will no doubt try to make excuses for this botched novel, but [author Stephanie] Meyer has put a stake through the heart of her own beloved creation."

2. Abstinence is not merely not-having-sex, but is apparently seen by some teensas a step towards having sex. Before sex is salient, not having sex is the default, and there's no thought of doing otherwise. Abstinence doesn't become a conscious choice until sex is an actual possibility. How this should change abstinence-focussed sex ed is a good question.

Shutting down dialog happens in both directions

The cases where people suggesting condoms as STD prevention are shouted down and find themselves in a hostile environment are well known. It also happens the other way, apparently: a story from Uganda about a 16 year old mocked for being pro-abstinence.

DURING a high school classroom discussion on HIV/AIDS prevention, the teacher asked the students: “What can be done to stop the spread of this fatal disease?” Some students talked about condoms and received the knowing affirmation of the teacher.

However when James, 16, raised his hand and answered: “We must promote and support young people to abstain until marriage,” he was attacked and stigmatised!

The teacher laughed derisively and mockingly told him, “Abstinence does not work for young people. It is just a dream.” James, who had chosen to abstain from sex after an abstinence presentation in Grade Eight, felt ashamed but he knew better. Other students began to mock and sneer at him. Again, James raised his hand and tried to explain how he had made the choice to abstain till marriage. “For some of us,” he said, “abstinence is not a dream, it is a present reality.”

The comments of the teacher had already created a hostile environment for James, and now he became the butt of the class jokes. Subsequently, James was mockingly labelled stereotype names ranging from “little mamas boy,” “ignorant kid”, “holy pope”, “virgin Mary” to “you are so ugly, that’s why you can't get any.” As if bent on breaking his will, two girls approached him and sarcastically told him they wanted to cure him of this dreaded disease called virginity. They recited stories of people who abstained and their genitals withered and fell off and that he was a good for nothing boy. They then walked away laughing.

Their use of gay pride terminology is perhaps unintentionally ironic:

Children who abstain are forced to survive shame and psychological violence by hiding in the “closet.” They are treated as lepers, social outcasts whose virginity is not a badge of pride, but rather a mark of disgrace. This is what I call “abstinence stigma.” While many parents teach their children the value of abstinence and saving sex for marriage, they are un-aware that the social contexts where young people make informed decisions about sex are contaminated with hostile and judgmental attitudes towards abstinence. It is a form of phobia.

Those who promote the fear of abstinence and virginity should be referred to as “abstino-phobes.” The word abstinophobia can aptly convey the irrational fear and discrimination meted out on the children who choose to abstain.

Paradoxically, while popular culture seeks to celebrate diversity, the only children who must go into the closet of shame are the “virgin and the abstainers.” Who will break the doors of this closet and tell these children to “break the shame” and walk in the abstinence pride?

We need to break the chains of “abstino-phobia” with campaigns of breaking the silence. We need school-based safe spaces of small groups where young people can meet for support without fear and stigma.

We need large school rallies where those who are in the abstinence closet of shame can come out loud and proud.

I've heard other anecdotes from young adults and even adults who received negative reactions or simple bafflement after their lack of sexual experience was revealed. Bias and stigma does go in both directions.

How to communicate weight loss messages to patients

A college friend of mine wrote in her live journal about her reaction to a doctor's initiation of the topic of weight at an appointment she had to address a recent injury. The doctor's approach seemed to be attempting to be non-intrusive: she gave a neutral factual statement that my friend looked from a picture like she used to be lighter. What happened next was interpreted as my friend as "asking if I knew I was going to DIE OF THE FAT."

Clearly something went wrong here in the immediate clinical encounter. Probably the doctor should have sensed from the conversation that my friend wasn't terribly open to discussing the subject and found it intrusive, especially since weight was completely irrelevant to the purpose of the appointment. If the doctor didn't want to just let the subject drop, she could have at most asked neutrally how she felt about that difference, and let it drop when my friend said that she felt fine.

But there's a larger question: how do physicians manage to acknowledge fat acceptance, but also send a message of obesity prevention?

Contrary to the blog comments, research is clear that on average mortality increases monotonically with BMI. Walt Willett's book has some nice plots of this. Fertility decreases monotonically with BMI. Even if recent research showing mortality improvements for some diseases in the BMI range 25 to 29 is completely free of confounding, so it's the weight which is associated with the decreased mortality rather than another factor that wasn't adequately adjusted for, it's only for a few of the evaluated diseases and mortality is much higher for BMI over 30.

Not to belabor the obvious, but these studies can only be refuted by studies of similar validity. They're not a massive conspiracy against anyone. They're just what the data revealed. Anyone who wants to reexamine the data to find a better explanation or find deemphasized null findings within the reports is free to do so, but so far no one has. And it's not impossible. See this reexamination of Framingham Heart Data on diet and cholesterol.

Anecdotes about outliers are just that. The studies hold on average, and while no one likes to think of themselves as average, all of us are average in most domains of life.

How can the overriding medical evidence be communicated in this sensitive way? I don't know, but here are some stabs at some of the issues:

- Many people feel powerless to change their weight, or feel that only heroic efforts can be successful. There does seem to be such a thing as a weight setpoint which is clearly resistant to change, see e.g. Gina Kolata's book.

- If it's not possible to change weight and live one's life in what one feels as a reasonable way, it makes a great deal of sense to accept weight as a given, and to see messages about overweight as taunting from people who just don't understand. Especially since sometimes they are.

- A never-overweight person sees their entire relationship with food, hunger, meals, clothes, and society completely differently and may therefore say stupid things like "Just lose weight," when it's anything but "just." Even the statements like "even 10 pounds makes a difference" while well-intentioned don't entirely help. One of the nicest but perennially thin people I know once said, "you're not that fat."

- It's not that easy, but it's usually not impossible either. In the spirit of self-discovery and self-experimentation while attaching no emotional weight to the results, people can design tests of the many approaches to food and diet, a few weeks long for each, to see whether anything changes their relationship to food or their weight.

And there are so many: beyond the obvious popular ones, the support-group types, there's the most kooky-seeming and yet potentially most profound by Berkeley psychology professor Seth Roberts.

-Logically, of course, it's not possible to prove a negative; it's not possible for people to prove what they perceive as reality that "weight loss is impossible for me" or "weight loss is only possible for me at an unacceptably high physical or emotional cost." But honestly these questions of obesity prevention and fat acceptance have such high emotional content on both sides that it's hard to say that there's much logic left.

No answers here, but maybe useful questions come out of it.

The ultimate in the because-I-think-you-need-it present

The CDC has created unintentionally funny health-themed greeting cards, such as:

- What have you been up to since your last HIV test? --- Let's go get tested again!

- Feel better from your surgery --- and walk around soon afterwards, so you don't get Deep Vein Thrombosis

- Don't just "Wait and See"! --- Just because a sore is painless and disappears doesn't mean that the disease is gone. Get tested for Syphilis today.



Is there any way to make a health-themed greeting card which does not seem preachy?

At least they had the good sense not to make "obesity awareness" greeting cards.