Category Archives: facts & data points

facts & data points, healthy habits, nutrition, policy

Katz on Butter

 

http://www.linkedin.com/today/post/article/20140327141338-23027997-bittman-butter-and-better-than-back-to-the-future

Bittman, Butter, and Better than Back to the Future

March 27, 2014

I generally appreciate the work and writing of Mark Bittman. But on one prior occasion, I was obligated to highlight his erroneous interpretation of an epidemiologic study about sugar, obesity, and diabetes. Mr. Bittman responded cordially and graciously when I pointed out his error, and more generally, his want of training or qualifications to offer up seemingly expert opinion to the public on research studies. I was pleased and gratified by the exchange that ensued between us, including a phone conversation and plans to meet for lunch, which alas, never came to fruition.

But old habits, it seems, die hard- and in this week’s New York Times, Mr. Bittman is indulging again in intellectual mission creep, with predictable consequences. While not trained as a chef, Mr. Bittman has established himself among the foodie elite, and is thus qualified to opine expertly on the culinary merits of butter. Or, at least, I am not qualified to say he is unqualified to do that- I defer to Jacques Pepin.

But Mr. Bittman is absolutely not qualified to assert the health effects of butter based on arecent meta-analysis I rather doubt he read in its somewhat excruciating detail. (In fact, he doesn’t even seem inclined to pretend he read it; he references the work several times, but in each case, the links he provides lead to someone else’s blog about the study, each reaching a conclusion- surprise- aligned with his own.) He should restrain himself from such inclinations to impersonate an expert, and the New York Times should set the bar higher. Experts should earn the rarefied real estate of New York Times pages only for their domain of actual expertise; the public probably expects, and certainly deserves, no less.

Mr. Bittman’s writing is, as ever, engaging and stylish. Overall, his column entitled “Butter is Back,” which turns out to be much about other things, such as limiting our overall intake of meat for ecological and humane reasons, is balanced, and thoughtful, and reaches generally reasonable conclusions about a diet of real foods, mostly plants – for the benefit of human health, our fellow species, and the planet alike. This is a topic near and dear to my heart, and one to which I have devoted considerable, recent effort.

But speaking of hearts, his conclusion that butter has now been exonerated of all harms formerly alleged is, in a word, wrong.

Since the study Mr. Bittman cites was about fatty acids, not foods, and only headlines in pop culture said anything about butter or cheese, we might begin with: what, exactly, are the saturated fatty acids in butter, and how did they fare specifically in the meta-analysis in question? I am betting you don’t know or care-but my point is, I bet the same of Mr. Bittman.

We could, perhaps productively, wade into just such weeds of the meta-analysis, but I’ve done that already, and see no value in redundancy here. My prior column is accessible to you. Note, as well, that colleagues have identified potentially quite important flaws in the actual analysis, the investigators themselves have conceded those flaws, and an outright retraction of the paper is at least being discussed.

But we can leave all of that alone and grind better grist altogether. Consider that the meta-analysis, even if sound, showed only that Western diets with lower and higher levels of saturated fat still produced roughly comparable levels of heart disease. It actually showed slightly less heart disease with lower saturated fat intake, but statistically speaking, that’s picking a nit, so we can let it go. Let’s accept that without addressing at all what replaces the saturated fat, a fairly typical Western diet produces about the same amount of heart disease whether higher or lower in saturated fat content. Substituting in Mr. Bittman’s leap of faith, this might mean that typical Western diets with higher or lower amounts of butter produce about the same amount of heart disease.

On this basis, Mr. Bittman says: bring back the butter.

Before you do, consider these points, in no particular order:

1) All ‘Western’ diets produce very high levels of heart disease, at least 80% of which has been shown to be outright preventable by a litany of studies spanning decades.

2) The new meta-analysis did NOT consider what was replacing the saturated fat in the diets of those who ate less, but others have told us that: mostly refined starch and sugar. Importantly, then, despite Mr. Bittman’s assertions that these are the ‘real’ culprits in our diets- diets lower in saturated fat did NOT show higher levels of heart disease, as we might expect if we were replacing a false culprit with the real ones (i.e., cutting saturated fat, adding sugar). So, the new study might just as well be interpreted to show that ‘adding sugar and starch to the diet in the place of saturated fat’ does not increase heart disease rates. So on what basis does this study indicate these are the ‘real’ culprits? Mr. Bittman just brought his preconceived notions along for the ride. (My view? Excesses of saturated fat, sugar, and refined starch are in on it together, and all still wanted for further questioning.)

3) The new study did show lower rates of heart disease with higher intake of omega-3 fat. There was a favorable trend with polyunsaturated fats in general, but this was not significant.

4) Overall, then, the study showed that some dietary fats can be beneficial to health, butsaturated fats as a class were not among them. The best the study said of saturated fats is:they don’t seem to make things worse than the prevailing status quo.

5) But to rephrase point 1: the status quo stinks!

6) Other studies have blown the status quo away. In his famous study years ago, Dean Ornish showed a relative 70% reduction in the rate of heart attack with a plant-based, low-fat diet that certainly did not feature butter.

7) Perhaps of more general interest: the Lyon Diet Heart Study showed exactly the same, impressive, relative 70% reduction in heart attack rates. But in this case, the intervention diet had no ascetic overtones; it was a Mediterranean Diet. The control diet, which resulted in standard –and thus appallingly high- rates of heart attack was a typical Western diet. But the Lyon Diet Heart Study, as the name suggests, was centered in Lyon, France- and conducted in European countries. The ‘typical’ diet was not American junk- it was the real-food diet of Northern Europe, dripping in, among other things, butter. Other Mediterranean Diet studies have shown much the same.

8) Combining point 7 with the new study could be said to show this: saturated fat (and therefore, maybe, butter) may not be bad for hearts and health compared to other things that are bad for hearts and health. But there is no evidence they are good for hearts and health. That hardly seems cause to start shmearing.

9) In contrast, a balanced portfolio of monounsaturated and polyunsaturated fats-characteristic of all of the world’s most healthful diets; particularly associated with the Mediterranean diet; and derived from foods such as olives, avocadoes, nuts, seeds, with or without fish and seafood- is decisively associated with lower rates of all chronic disease, dramatic reduction in the rate of heart attack, and reduction in the rate of premature death overall. And that’s without buttering it up.

10) Well, I guess I’m done. Just reread 1-9, and there you go.

I don’t think butter is poison. Go ahead and have some if so inclined. But do it for pleasure, not health. The new study was not about butter, but had it been, it could have concluded that there are things we can eat instead that are just as good, or just as bad. Either way, there was no hint that adding butter to our diets would improve our health. Since other studies do show us how to do just that, why would we settle for a lateral move, and stay mired in a place where coronary disease is practically a middle-aged rite of passage? There are places around the world that get the healthy living formula right where heart disease is all but unknown.

I have opinions about cuisine-but they are just opinions. I cannot, and do not, claim culinary expertise. Mr. Bittman, by popular affirmation, can-and I, like many of you, am happy to listen and learn when he does so. But he is no scientist, and when he forgets that, he becomes a potential danger to public heath, misdirecting his considerable influence, and exploiting the faith of his followers. When it comes to clear messaging about nutrition and health, we all should be a bit more careful about which side of the bread is being buttered, and who wields the knife.

If you don’t mind living in a world where everyone you know over age 50 is on multiple medications to fix what lifestyle as medicine could fix far better, by all means add back the butter. If you think it’s normal that most adults of a certain age have had their chests opened up or their coronaries ballooned open, butter away.

But we certainly know how to do far better than such variations on the theme of eating badly. Even in the home of the famous French paradox, replacing butter with olive oil –among other things- slashed rates of heart disease. In my unprofessional opinion, cold-pressed, extra virgin kalamata olive oil on fresh, whole grain bread is sublime. In my professional opinion, it’s good for me. I’m sticking with it for both reasons.

Butter is not, and never was, a singular nemesis– any more than sugar is, or wheat is. But butter never did our health any favors either- however it may treat our taste buds. Advice to add it back takes us back, not forward, to our nutritional future. We know how to do far better.

-fin

Dr. David L. Katz has authored three editions of a nutrition textbook for health care professionals. He is editor-in-chief of the peer-reviewed journal, Childhood Obesity, and President of the American College of Lifestyle Medicine. He was commissioned by Annual Review in Public Health to write the review article, Can We Say What Diet is Best for Health? He is the author, most recently, ofDisease Proof. He likes olive oil.

facts & data points, healthcare, policy

Obesity Society of Australia

good obesity and diabetes stats, otherwise fluff…

http://www.medicalobserver.com.au/news/govts-should-weigh-in-on-obesity

Govts should weigh in on obesity

22nd Apr 2014

THE release in 1997 of the National Health and Medical Research Council’s report, Acting on Australia’s Weight: a Strategic Plan for the Prevention of Overweight and Obesity, was supposed to be a watershed.

Associate Professor Tim Gill

Executive Officer, Australian and New Zealand Obesity Society

This was the first time a national agency anywhere in the world had produced a national action plan that recognised the seriousness of the growing obesity problem and set out a strategy to deal with it.

Great anticipation surrounded the level and vigour of action on treatment and obesity prevention it would stimulate.

Alas, after several years of procrastination, several government taskforces and innumerable additional reports (with mostly the same recommendations) the original report has been re-branded from Acting on Australia’s Weight to ‘Waiting on Australia to Act’ by health advocates frustrated by continued unwillingness by successive Australian governments to take up the tougher recommendations required.

All governments now acknowledge the seriousness of the public health problem of obesity and the financial and social burden of obesity-related conditions.

However, they proffer a confusing range of reasons for their unwillingness to act upon recommendations from their own expert committees.

Among the most perplexing rationales for inaction include: obesity is not a disease; we cannot act without certainty that this intervention will be effective; obesity is a lifestyle problem that requires personal rather than government action; and we do not want to create a nanny state.

In isolation, some of these justifications appear valid, especially when espousing a need for evidence-based policy and a desire to avoid causing unintended harm.

However, few stand up to critical analysis within the context of type of response required to make headway.

Since the release of Acting on Australia’s Weight, the prevalence on obesity has risen from 18.7% to 28.3% and now almost two-thirds of Australian adults are overweight or obese.

The predicted avalanche of weight-related chronic disease is beginning to emerge. The level of type 2 diabetes has more than doubled since 1995 and now affects 4.2% of the adult population.

Every day 280 Australians develop diabetes, and the Baker IDI Institute estimates there will be 2.5—3 million people with diabetes by 2025 and about 3.5 million by 2033. These sorts of figures should see governments eager to identify and support any action. Instead we have reached a point where the range of strategies acceptable to governments is narrowing. Potentially effective interventions have been ruled off the table as a consequence of a combination of political, philosophical and technical considerations.

It is true there are no easy or quick solutions to the problem of Australia’s expanding weight. It is also true that governments alone cannot solve this problem; it will take a concerted effort from individuals, communities, professionals, industry and all sectors of society.

Governments must provide leadership, however. This necessitates tough decisions in the face of corporate resistance and public self-interest that demonstrate commitment in tackling obesity and perceptions around this issue.

Telling people battling with genetic and physiological liabilities overlaid with an environment that promotes sedentary behaviour and overconsumption of food that they must take personal responsibility is not leadership.

But preparedness to embrace a range of structural, regulatory or fiscal reforms that have the potential to push the environment in a direction that supports appropriate behaviour change provides a clear indication of the government’s stance.

This display of leadership is likely to achieve more in terms of modelling and endorsement of additional action than the direct impact of the intervention itself. And that is the role of government.

data saving lives, entrepreneurship, facts & data points, health market quality, healthcare, healthy habits, nutrition, policy, politics, quantified self, rapid learning health systems, research methodology

RWJF Report: Personal Data for the Public Good

Solid report on personal health data. Interesting observation re. (lack of) alignment between research and business objectives… i.e. public vs private goods?

http://www.rwjf.org/en/research-publications/find-rwjf-research/2014/03/personal-data-for-the-public-good.html

Report: http://www.rwjf.org/content/dam/farm/reports/reports/2014/rwjf411080

PDF:

1. Executive Summary
Individuals are tracking a variety of health-related data via a growing number of wearable devices and smartphone apps. More and more data relevant to health are also being captured passively as people communicate with one another on social networks, shop, work, or do any number of activities that leave “digital footprints.”
Almost all of these forms of “personal health data” (PHD) are outside of the mainstream of traditional health care, public health or health research. Medical, behavioral, social and public health research still largely rely on traditional sources of health data such as those collected in clinical trials, sifting through electronic medical records, or conducting periodic surveys.
Self-tracking data can provide better measures of everyday behavior and lifestyle and can fill in gaps in more traditional clinical data collection, giving us a more complete picture of health. With support from the Robert Wood Johnson Foundation, the Health Data Exploration (HDE) project conducted a study to better understand the barriers to using personal health data in research from the individuals who track the data about their own personal health, the companies that market self-tracking devices, apps or services and aggregate and manage that data, and the researchers who might use the data as part of their research.
Perspectives
Through a series of interviews and surveys, we discovered strong interest in contributing and using PHD for research. It should be noted that, because our goal was to access individuals and researchers who are already generating or using digital self-tracking data, there was some bias in our survey findings—participants tended to have more education and higher household incomes than the general population. Our survey also drew slightly more white and Asian participants and more female participants than in the general population.
Individuals were very willing to share their self-tracking data for research, in particular if they knew the data would advance knowledge in the fields related to PHD such as public health, health care, computer science and social and behavioral science. Most expressed an explicit desire to have their information shared anonymously and we discovered a wide range of thoughts and concerns regarding thoughts over privacy.

Equally, researchers were generally enthusiastic about the potential for using self-tracking data in their research. Researchers see value in these kinds of data and think these data can answer important research questions. Many consider it to be of equal quality and importance to data from existing high quality clinical or public health data sources.
Companies operating in this space noted that advancing research was a worthy goal but not their primary business concern. Many companies expressed interest in research conducted outside of their company that would validate the utility of their device or application but noted the critical importance of maintaining their customer relationships. A number were open to data sharing with academics but noted the slow pace and administrative burden of working with universities as a challenge.
In addition to this considerable enthusiasm, it seems a new PHD research ecosystem may well be emerging. Forty-six percent of the researchers who participated in the study have already used self-tracking data in their research, and 23 percent of the researchers have already collaborated with application, device, or social media companies.
The Personal Health Data Research Ecosystem
A great deal of experimentation with PHD is taking place. Some individuals are experimenting with personal data stores or sharing their data directly with researchers in a small set of clinical experiments. Some researchers have secured one-off access to unique data sets for analysis. A small number of companies, primarily those with more of a health research focus, are working with others to develop data commons to regularize data sharing with the public and researchers.
SmallStepsLab serves as an intermediary between Fitbit, a data rich company, and academic researchers via a “preferred status” API held by the company. Researchers pay SmallStepsLab for this access as well as other enhancements that they might want.
These promising early examples foreshadow a much larger set of activities with the potential to transform how research is conducted in medicine, public health and the social and behavioral sciences.

Opportunities and Obstacles
There is still work to be done to enhance the potential to generate knowledge out of personal health data:
•
Privacy and Data Ownership: Among individuals surveyed, the dominant condition (57%) for making their PHD available for research was an assurance of privacy for their data, and over 90% of respondents said that it was important that the data be anonymous. Further, while some didn’t care who owned the data they generate, a clear majority wanted to own or at least share ownership of the data with the company that collected it.
•
Informed Consent: Researchers are concerned about the privacy of PHD as well as respecting the rights of those who provide it. For most of our researchers, this came down to a straightforward question of whether there is informed consent. Our research found that current methods of informed consent are challenged by the ways PHD are being used and reused in research. A variety of new approaches to informed consent are being evaluated and this area is ripe for guidance to assure optimal outcomes for all stakeholders.
•
Data Sharing and Access: Among individuals, there is growing interest in, as well as willingness and opportunity to, share personal health data with others. People now share these data with others with similar medical conditions in online groups like PatientsLikeMe or Crohnology, with the intention to learn as much as possible about mutual health concerns. Looking across our data, we find that individuals’ willingness to share is dependent on what data is shared, how the data will be used, who will have access to the data and when, what regulations and legal protections are in place, and the level of compensation or benefit (both personal and public).
•
Data Quality: Researchers highlighted concerns about the validity of PHD and lack of standardization of devices. While some of this may be addressed as the consumer health device, apps and services market matures, reaching the optimal outcome for researchers might benefit from strategic engagement of important stakeholder groups.

We are reaching a tipping point. More and more people are tracking their health, and there is a growing number of tracking apps and devices on the market with many more in development. There is overwhelming enthusiasm from individuals and researchers to use this data to better understand health. To maximize personal data for the public good, we must develop creative solutions that allow individual rights to be respected while providing access to high-quality and relevant PHD for research, that balance open science with intellectual property, and that enable productive and mutually beneficial collaborations between the private sector and the academic research community.

complex adaptive systems, entrepreneurship, facts & data points, healthcare, healthy habits, policy, quantified self, rapid learning health systems, research methodology

Healthy Ageing Japan-style

 

http://www.abc.net.au/radionational/programs/saturdayextra/japan27s-aging-population/5397864

Japan’s ageing population

Saturday 26 April 2014 8:30AM
Japan's oldest communityIMAGE: RESIDENTS OF JAPAN’S OLDEST COMMUNITY (LATELINE)

A quarter of Japanese people are now aged over 65, with predictions that nearly half the population will reach that age by the end of the century.

In Japan people don’t just live longer, they work longer, stay healthier and approach old age in some interesting and innovative ways.

One policy initiative is old age day care which is well used and well organised in Japan.

Guests

Professor John Creighton Campbell
Visiting scholar, Institute of Gerontology at Tokyo University

Credits

Presenter
Dr Norman Swan
Producer
Kate Pearcy
data saving lives, facts & data points, healthy habits, musings, nutrition, policy, rapid learning health systems, storytelling

“Eat right. Get physical activity. Don’t smoke. Alcohol in moderation. Spend time with friends.”

http://www.vox.com/health-care/2014/4/22/5640636/dont-read-more-health-books-read-these-14-words

Don’t read more health books. Read these 14 words.

Updated by  on April 22, 2014, 3:30 p.m. ET 

You can do this. But you can also walk for 30 minutes a day.Donald Miralle/Getty Images for NASCAR

Thomas Frieden has a scary job. As director of the Centers for Disease Control and Prevention, he gets the call when infections begin defeating all known antibiotics, or Ebola resurfaces, or overdoses from prescription opiates begin skyrocketing.

Meanwhile, I’m the kind of person who won’t even go see movies about disease outbreaks. So when I sat down with Frieden recently, I asked him the question hypochondriacs need to know: What has all this data taught him to fear? What does he tell his family to do differently?

His answer was borderline dull:

Very little is different really. It’s basic. Wash your hands regularly. Get regular physical activity. Eat foods you love that are healthy. That’s one of the things that’s so challenging. Take physical activity as an example. You don’t have to have much, 30 minutes a day. Doing that, which can be three 10-minute walks, is going to make a huge difference in your life. You’ll feel better even if you don’t lose an ounce. You will be much less likely to have high blood pressure, high cholesterol, cancer, arthritis, depression. You’ll sleep better. And it doesn’t cost a cent.

There’s a lot a of things that can be done that are not very difficult and can make a really big difference. Of course, get your shots, get vaccination, get a flu shot every year and see the doctor regularly and if you have a problem make sure to get follow up.

The broader point — which came up again and again  in our interview — is that the main threats to health aren’t spectacular. People die from heart disease, car accidents, and tobacco a lot more often than they’re killed by Ebola, terrorism, and heroin.

The CDC Director’s reply reminded me of Michael Pollan’s famous, commonsense triplet about diet: “Eat food. Not too much. Mostly plants.” I asked whether Frieden had similarly concise advice. He did.

“Eat right. Get physical activity. Don’t smoke. Alcohol in moderation. Spend time with friends.”

Unlike a lot of health treatments, weird diets, and fancy exercise regimes you’ll read about, this advice is backed up by reams of rock-solid evidence — and following it costs next to nothing.

So there it is: in less than 15 words, the US official who probably knows better than anyone else what might kill you explains how to protect yourself.

Here’s my full interview with Frieden:

 


cool, data saving lives, entrepreneurship, facts & data points, health market quality, healthcare, healthy habits, policy, quantified self, rapid learning health systems, storytelling

The Story of Digital Health

http://www.nuviun.com/nuviun-digital-health

good infographics…

 

Digital Health Venn Nuviun

 

http://storyofdigitalhealth.com/infographic/

 

Digital_Health_Infographic

Infographic

I created this conceptual infographic illustrating the increasing health benefits achievable with digital health with the great team at Misfit Wearables. You can download a high-resolution version by clicking on the image.

Digital_Health_Infographic

References:
Number of people sequenced
“250,000 human genomes will be fully sequenced by the end of 2012, 1 million by 2013, and 5 million by 2014″ -Topol, Eric (2011-12-02). The Creative Destruction of Medicine: How the Digital Revolution Will Create Better Health Care (p. 102). Perseus Books Group. Kindle Edition.

Also, compliments of Story of Digital Health strategic partner nuviun, there’s this interactive diagram of the digital health landscape…

nuviun-digital-health-landscape

 

facts & data points, healthy habits, nutrition

Benefits of Intermittent Fasting

– weight loss
– postponement of dementia (eq. of 10 yrs)

http://www.nutritionaction.com/daily/diet-and-weight-loss/are-there-benefits-of-intermittent-fasting/

Are There Benefits of Intermittent Fasting?

Here is what researchers have discovered about fasting some days per week

 • March 24, 2014

“We’ve known for a long time that if you reduce the calorie intake of rats or mice, they live much longer,” says Mark Mattson, chief of the laboratory of neurosciences at the National Institute on Aging (NIA) in Baltimore.

What happens in species closer to humans is more complicated. Rhesus monkeys fed 30 percent fewer calories lived longer in a study at the University of Wisconsin, but not in a study at the NIA.

Act now to download your FREE copy of Diet and Weight Loss: Trim Calories Per Bite to Trim Pounds without cost or obligation.

Why the different results? One possibility: The Wisconsin monkeys were fed fewer calories than monkeys fed as much high-sugar, high-fat food as they wanted. In contrast, the NIA monkeys were fed fewer calories than monkeys fed as much (low-sugar, low-fat) food as they needed to maintain their weight.

“One take-home message is that if you are an overweight monkey like those in Wisconsin, cutting back on calories will extend your lifespan,” says Mattson. “Whereas if you are eating a healthy diet and not overweight like the NIA monkeys, cutting back on calories may not extend your life, although you may experience some health benefits.”

What if you’re human? In the first good study in normal-weight or slightly overweight (but not obese) people, researchers asked roughly 150 men and women to consume 25 percent fewer calories at each meal than they needed to maintain their weight, and 75 similar people to follow their normal diet, for two years.

The calorie cutters managed to eat 12 percent fewer calories, and they lost 10 percent of their body weight. That may explain why their blood pressure was lower and their insulin worked better than those who ate their normal diets.

“They lowered their risk factors for heart attack, stroke, and diabetes,” says Eric Ravussin, director of the Nutrition Obesity Research Center at the Pennington Biomedical Research Center in Baton Rouge, Louisiana. The study hasn’t yet been published.

Why didn’t the calorie cutters cut more? “Eating less than you would like to every day is a struggle,” says Ravussin. “Some people can do it, but many cannot.”

But cutting calories only on some days may be easier.

Mon, Tues, Weds, Thurs, Fri, Sat, Sun

“There’s the alternate-day modified fast,” says Ravussin. “Every other day you eat only one meal with maybe 30 percent of your normal daily calorie intake.”

And there’s the 5:2 diet, in which you eat a normal diet five days of the week, and only 30 percent of what you would normally eat on the other two days.

“Whichever it is, you have to make sure you don’t overeat on the normal days,” cautions Ravussin.

So far, intermittent fasting shows promise in both animals and people.

“Laboratory animals that get no food at all on alternate days live about 30 percent longer than animals that eat their regular diets every day,” says Mattson.

In humans, the 5:2 plan seems to hold an edge over fasting every day.

In two of the best studies, Mattson and colleagues divided 166 overweight middle-aged women into two groups. Both were told to cut calories by 25 percent—one by trimming the calories in each meal, the other by following a 5:2 plan.

In both studies, the women were told to eat a high-protein “Mediterranean-type” diet with fruits, vegetables, whole grains, nuts, seafood, and olive oil, and only moderate amounts of dairy, poultry, eggs, and lean red meat.

On the two fasting days of the 5:2 diet, one study prescribed just four cups of low-fat milk, four servings of vegetables, and one serving of fruit. The other study prescribed about 9 oz. of lean protein, 3 servings of low-fat dairy, 4 servings of low-carb vegetables, and a low-carb fruit. Both also recommended low-calorie drinks and a multivitamin-and-mineral.

In each study, both calorie-cutting groups lost about the same weight. “But insulin resistance declined more in the 5:2 groups than in those who cut calories daily,” says Mattson. And in the three-month trial (the other trial lasted six months) the women on the 5:2 regimen lost more body fat.

Why did the 5:2 dieters do better? They were more likely to stick to their plan. “And on the two days that they ate only 500 to 600 calories, their metabolism shifted to burning fat,” says Mattson.

Brain Diet?

Middle-aged rats, after being deprived of all food every other day for three months, lost 23 percent of their body weight and had better motor coordination and cognitive skills than similar rats who could eat all they wanted.

One possible reason: “Intermittent fasting increases brain levels of a protein that stimulates the growth of new brain cells and the connections between them,” says Mattson.

“We think what’s happening is that when you’re hungry, your brain cells are more active so you can figure out how to find food,” he explains. “During evolution, those who were able to figure out how to get food were the ones who survived.”

Today, our brain cells may respond in a similar way when we’re hungry.

Intermittent fasting also seems to postpone dementia, at least in animals. In mice bred to show signs of Alzheimer’s disease by middle age, eating only every other day delays the onset of dementia by the human equivalent of about 10 years.

“That’s a big effect,” says Mattson. “But we’re nowhere near being able to say the same about humans.”

The bottom line: Cutting calories may not prolong your life, but it may lower your blood pressure and make your insulin work better.

Sources: Science 325: 201, 2009; Nature 489: 318, 2012; Mech. Ageing Dev. 55: 69, 1990; Int. J. Obes. 35: 714, 2011; Br. J. Nutr. 110: 1534, 2013; Age 34: 917, 2012; Endocrinology 144: 2446, 2003; Neurobiol. Dis. 26: 212, 2007.