Wednesday, October 23, 2013

Follow-up to "Fat Adapted Horses"

Jimmy Moore posted this image today [scroll down]:

"This poster was actually on display at the Minnesota State Fair this year–pretty cool stuff!"

Indeed. This is the point John Durant makes in his new book, The Paleo Manifesto: we're not the only critters that have problems with a high-carb, non-ancestral diet.

[Original post]

Monday, October 21, 2013

Low-Carb Athletes: Jenson Button, 2009 Formula One World Champion

Jenson Button is one of the best race-car drivers in the world. Contrary to most people's expectations, driving a race car, especially an F1 car, is an athletically-demanding task. (And for all you Americans who are not familiar with F1, it's the most popular sport in the world with the highest-paid athletes.)
"His hobbies include mountain biking, competing in triathlons and body boarding..."
No slouch, then. This article ("Nigel Mansell: F1 weight limits for 2014 'disgraceful'") quotes Button:
"I love fitness training but there are things I can't do because I have to be a set weight - not eat carbohydrates, not build muscle. And next year it will be worse. I don't think any team will have ballast next year."
Interesting. Unlike Lindsey Vonn, who rarely mentions her diet, Button's pretty open about it.
Telegraph: "While Button said he was in no danger of developing an eating disorder, he admitted that he fasts before each race and “never” eats carbohydrates."
AskMen: "Keeping Jenson trim is a low-carb diet which, as he went on to tell us, was pretty tough to begin with, “When you grow up eating cereal, toast and fruit for breakfast like I did, it is initially very difficult to adjust. These days I’ll have a steak for breakfast with mushrooms and tomatoes, or I’ll have fish like salmon or haddock. Then I have the same thing at lunch – fish or meat with vegetables or salad – then the same for dinner. I’m not intolerant to carbs but if I eat too many I’d put weight on very quickly.”

"When pressed on what he missed eating the most he was quick to answer, “Desserts. I’ve got a very sweet tooth. I miss banoffee pie, sticky toffee pudding, that sort of thing. The worst thing is when I’m out for dinner over a Grand Prix weekend with Jessica (Michibata – Jenson’s Japanese girlfriend) and she orders dessert. I’m just like ‘How dare you? That’s so unfair!’”
Dehydration is a major concern in an F1 car, as you're often baking, fully dressed (including gloves and a helmet), in an open car on a hot track in the summer sun for hours:
"The two formulas created by Lucozade are specially balanced to aid with water retention and absorption into the blood stream. The hydration formula is used across the entire race weekend and is aimed at maintaining hydration especially in the hotter climes. Helen Cowie, the technical director, at GlaxoSmithKline Research & Development behind the drinks explained, “It’s low in carbs and a has a tightly maintained level of sodium within the drink that leaves it surprisingly salty in taste. Sodium speeds up the absorption of the liquid by your body, meaning that the drivers don’t sit there with a belly fluid of drinking sloshing around them, which can lead to stomach cramps.”"
Interesting, as it corresponds with Wolverine's experience with hydration: he also found that adding salt to the water aided in absorbtion.
SportsKeeda: "Jenson’s impressive physical condition can be attributed to two things: his fitness programme and his diet. He works out for up to five hours per day when he’s not at a racetrack and he follows a low-carb diet that has been tailored to his sport’s needs.

"To keep his competitive instincts razor-sharp, he competes regularly in triathlons (swimming, cycling and running). After the season-opening Australian Grand Prix he contested a triathlon in Hawaii and he’s maintained a strict nutritional programme.

"“I work out a lot,” says Jenson. “I need to be fit to do my job and a fit body results in a fit mind. However, I’ve benefited almost as much through improving my diet. It’s a cliché, but we are what we eat and I’ve worked hard with a nutritionist to ensure that I’m eating the right things at the right time of day.

"“I’ve lost three percent body fat by not eating carbohydrates for breakfast. No cereal or toast for Jenson Button! The benefits of eating the right things are huge; it’s something that I underestimated until quite recently.” [My emphasis.]

"The only potential snag during Sunday’s 56-lap Malaysian Grand Prix is the water bottle that Jenson will have strapped into the cockpit of his McLaren MP4-26. Even with his newfound levels of fitness, he’ll struggle in the race without a water bottle because he’ll be performing in cockpit temperatures of more than 50 degrees. [Centigrade, that's 122 F, for a two-hour race.]

"“It doesn’t matter how fit you are,” says Jenson. “If you get dehydrated, your physical performance drops off and your concentration is affected. A couple of years ago my water bottle stopped working on lap two at Sepang and by the end of the race I was suffering a lot.

"“The first thing that happened was that I got cold. Despite the excruciating heat I was shivering in the cockpit, which is a crazy thought. My eyesight then started to go and by the end of the race some things became blurred. That’s a horrible thing to happen in a racing car! As long as my water bottle works on Sunday, I’ll be fine.”
And if you ask Button for weight-loss tips, this is what he'll tell you:
This is an interview with Button's physiotherapist, Mike Collier:
On his diet and whether it is mostly pasta:

"No, the opposite, really. We try and avoid carbohydrates from Thursday through to Saturday evening. Saturday evening he will have carbohydrates. It's about making sure there is adequate protein there for recovery and repair, and that he eats reasonably regularly so that he maintains more of a constant blood sugar. People think about pastas and rice and all these carbohydrates being very good for you; they are, provided that you are exercising to be able to burn them. Otherwise it is just like eating too much fat: It will increase your weight. As driver weights are important, we play around with it a little bit to ensure that his weight is very good, that he has enough energy, that he is also repairing himself and recovering through protein. So his meal before the race will be a salad-based chicken dish. There is carbohydrate, but in his drink."
So he's got a bit to learn. Not yet a paleo diet, but a typical low-carb diet. Button would probably get even trimmer adding more fat and reducing protein, as Jimmy Moore demonstrated to the world. Eating fat does not make you fat. Maybe Button can consult with Dr. Noakes...

Tuesday, October 15, 2013

Seven Myths About Obesity

Myths, Presumptions, and Facts about Obesity — New England Journal of Medicine:


We review seven myths about obesity, along with the refuting evidence. Table 1 (Seven Myths about Obesity) provides anecdotal support that the beliefs are widely held or stated, in addition to reasons that support conjecture.

Small Sustained Changes in Energy Intake or Expenditure

Myth number 1:
Small sustained changes in energy intake or expenditure will produce large, long-term weight changes.

Predictions suggesting that large changes in weight will accumulate indefinitely in response to small sustained lifestyle modifications rely on the half-century-old 3500-kcal rule, which equates a weight alteration of 1 lb (0.45 kg) to a 3500-kcal cumulative deficit or increment.5,6 However, applying the 3500-kcal rule to cases in which small modifications are made for long periods violates the assumptions of the original model, which were derived from short-term experiments predominantly performed in men on very-low-energy diets (<800 kcal per day).5,7 Recent studies have shown that individual variability affects changes in body composition in response to changes in energy intake and expenditure,7 with analyses predicting substantially smaller changes in weight (often by an order of magnitude across extended periods) than the 3500-kcal rule does.5,7 For example, whereas the 3500-kcal rule predicts that a person who increases daily energy expenditure by 100 kcal by walking 1 mile (1.6 km) per day will lose more than 50 lb (22.7 kg) over a period of 5 years, the true weight loss is only about 10 lb (4.5 kg),6 assuming no compensatory increase in caloric intake, because changes in mass concomitantly alter the energy requirements of the body.

Setting Realistic Weight-Loss Goals

Myth number 2:
Setting realistic goals for weight loss is important, because otherwise patients will become frustrated and lose less weight.

Although this is a reasonable hypothesis, empirical data indicate no consistent negative association between ambitious goals and program completion or weight loss.8 Indeed, several studies have shown that more ambitious goals are sometimes associated with better weight-loss outcomes (see the Supplementary Appendix).8 Furthermore, two studies showed that interventions designed to improve weight-loss outcomes by altering unrealistic goals resulted in more realistic weight-loss expectations but did not improve outcomes.

Rate of Weight Loss

Myth number 3:
Large, rapid weight loss is associated with poorer long-term weight-loss outcomes, as compared with slow, gradual weight loss.

Within weight-loss trials, more rapid and greater initial weight loss has been associated with lower body weight at the end of long-term follow-up. 9,10 A meta-analysis of randomized, controlled trials that compared rapid weight loss (achieved with very-low-energy diets) with slower weight loss (achieved with low-energy diets — i.e., 800 to 1200 kcal per day) at the end of short-term follow-up (<1 yr) and long-term follow-up (≥1 year) showed that, despite the association of very-low-energy diets with significantly greater weight loss at the end of short-term follow-up (16.1% of body weight lost, vs. 9.7% with low-energy diets), there was no significant difference between the very-low-energy diets and low-energy diets with respect to weight loss at the end of long-term follow-up.10 Although it is not clear why some obese persons have a greater initial weight loss than others do, a recommendation to lose weight more slowly might interfere with the ultimate success of weight-loss efforts.

Diet Readiness

Myth number 4:
It is important to assess the stage of change or diet readiness in order to help patients who request weight-loss treatment.

Readiness does not predict the magnitude of weight loss or treatment adherence among persons who sign up for behavioral programs or who undergo obesity surgery.11 Five trials (involving 3910 participants; median study period, 9 months) specifically evaluated stages of change (not exclusively readiness) and showed an average weight loss of less than 1 kg and no conclusive evidence of sustained weight loss (see the Supplementary Appendix). The explanation may be simple — people voluntarily choosing to enter weight-loss programs are, by definition, at least minimally ready to engage in the behaviors required to lose weight.

Importance of Physical Education

Myth number 5:
Physical-education classes, in their current form, play an important role in reducing or preventing childhood obesity.

Physical education, as typically provided, has not been shown to reduce or prevent obesity. Findings in three studies that focused on expanded time in physical education12 indicated that even though there was an increase in the number of days children attended physical-education classes, the effects on body-mass index (BMI) were inconsistent across sexes and age groups. Two meta-analyses showed that even specialized school-based programs that promoted physical activity were ineffective in reducing BMI or the incidence or prevalence of obesity. 13 There is almost certainly a level of physical activity (a specific combination of frequency, intensity, and duration) that would be effective in reducing or preventing obesity. Whether that level is plausibly achievable in conventional school settings is unknown, although the dose–response relationship between physical activity and weight warrants investigation in clinical trials.

Breast-Feeding and Obesity

Myth number 6:
Breast-feeding is protective against obesity.

A World Health Organization (WHO) report states that persons who were breast-fed as infants are less likely to be obese later in life and that the association is “not likely to be due to publication bias or confounding.”14 Yet the WHO, using Egger's test and funnel plots, found clear evidence of publication bias in the published literature it synthesized.15 Moreover, studies with better control for confounding (e.g., studies including within-family sibling analyses) and a randomized, controlled trial involving more than 13,000 children who were followed for more than 6 years16 provided no compelling evidence of an effect of breast-feeding on obesity. On the basis of these findings, one long-term proponent of breast-feeding for the prevention of obesity wrote that breast-feeding status “no longer appears to be a major determinant” of obesity risk17; however, he speculated that breast-feeding may yet be shown to be modestly protective, current evidence to the contrary. Although existing data indicate that breast-feeding does not have important antiobesity effects in children, it has other important potential benefits for the infant and mother and should therefore be encouraged.

Sexual Activity and Energy Expenditure

Myth number 7:
A bout of sexual activity burns 100 to 300 kcal for each participant.

The energy expenditure of sexual intercourse can be estimated by taking the product of activity intensity in metabolic equivalents (METs),18 the body weight in kilograms, and time spent. For example, a man weighing 154 lb (70 kg) would, at 3 METs, expend approximately 3.5 kcal per minute (210 kcal per hour) during a stimulation and orgasm session. This level of expenditure is similar to that achieved by walking at a moderate pace (approximately 2.5 miles [4 km] per hour). Given that the average bout of sexual activity lasts about 6 minutes,19 a man in his early-to-mid-30s might expend approximately 21 kcal during sexual intercourse. Of course, he would have spent roughly one third that amount of energy just watching television, so the incremental benefit of one bout of sexual activity with respect to energy expended is plausibly on the order of 14 kcal.
They sum: "There is almost certainly a level of physical activity (a specific combination of frequency, intensity, and duration) that would be effective in reducing or preventing obesity."

Despite all evidence to the contrary.

Is there any bit of medical advice on exercise and obesity that's not covered above? LOL.

Monday, October 7, 2013

Interviews With Daniel Lieberman And Reviews Of His "The Story Of The Human Body"

Newest first:

Minds and Brains: Book Review: Daniel Lieberman’s The Story of the Human Body.

Lieberman argues that all of these diseases are in some sense a result of cultural evolution speeding ahead of natural evolution with the result that have humans manufactured a psychologically comfy and satisfying environment that is paradoxically unhealthy without fundamentally affecting our reproductive fitness. Lieberman calls this this paradoxical unhealthiness “dysevolution”.

The Colbert Show: Daniel Lieberman. Interview starts at about minute 14.

PaleoRunner: "The Story of the Human Body: Daniel Lieberman" (embedded below):

Food Navigator (this site is so annoying that I caution against clicking on the link, but include for completeness): "Type 2 diabetes a ‘mismatch disease’ for our Paleolithic bodies"

The Guardian: "The Story of the Human Body: Evolution, Health and Disease by Daniel Lieberman – Review"

National Public Radio: "How Our Stone Age Bodies Struggle To Stay Healthy In Modern Times"

Mail Tribune: "The Human Body Wasn't Built For Modern Life"

Boston Globe: "‘Human Body’ author talks ‘mismatch diseases’"

Everyday eBook: "The Story of the Human Body: Straight Answers to Big Questions"

Outside Online: "The Human Body has a Story to Tell"

Far North Endurance: "A review of The Story of the Human Body, by Daniel Lieberman"

Harvard Magazine: "Harvard professor Daniel Lieberman discusses health and human evolution"

Is Science Broken? Part 8: "Science’s Sokal moment"

An interesting experiment:

"John Bohannon, a biologist at Harvard with a side gig as a science journalist, wrote his own Sokalesque paper describing how a chemical extracted from lichen apparently slowed the growth of cancer cells. He then submitted the study, under a made-up name from a fictitious academic institution, to 304 peer-reviewed journals around the world."

But it doesn't really demonstrate that something is wrong with institutional Science, per se; unlike the other examples in this series.

"The publications Dr Bohannon selected for his sting operation were all open-access journals. These make papers available free, and cover their costs by charging authors a fee (typically $1,000-2,000). Policymakers have been keen on such periodicals of late. Since taxpayers already sponsor most academic research, the thinking goes, providing free access to its fruits does not seem unreasonable. But critics of the open-access model have long warned that making authors rather than readers their client risks skewing publishers’ incentives towards tolerating shoddy science."

Bohannan demonstrates that most of the "open-access" journals shouldn't exist, and that the policymakers, as usual, are doing more harm than good. I agree that science paid for by the public should be freely available to the public, but too many of these open-access journals seem to be simply viewing this as a gold-rush-style business opportunity; quality be damned.