Is aerobic fitness or BMI the better predictor of academic performance?

Image: Mosborne01Is a child’s weight or their aerobic fitness the better predictor of academic performance? Researchers of the Partnership for Healthy Lincoln in Nebraska studied this question in fourth- to eighth-grade students and published their findings in the August 2013 Journal of Pediatrics.

“Aerobic fitness was defined by entering the healthy fitness zone of Fitnessgram's Progressive Aerobic Cardiovascular Endurance Run, which has been shown to correlate highly with maximum oxygen consumption.” 

Academic performance was assessed in relation to passing the Nebraska State Accountability math and reading tests. Adjustments were made for factors such as age, gender, body mass index (BMI), and free/reduced lunch status.

“After adjustment, aerobically fit students had greater odds of passing the NeSA math and reading tests compared with aerobically unfit students.”

The researchers concluded:

“Aerobic fitness was a significant predictor of academic performance; weight status was not. Although decreasing BMI for an overweight or obese child undoubtedly improves overall health, results indicated all students benefit academically from being aerobically fit regardless of weight or free/reduced lunch status. Therefore, to improve academic performance, school systems should focus on the aerobic fitness of every student.”

Source: Evidence that aerobic fitness is more salient than weight status in predicting standardized math and reading outcomes in fourth- through eighth-grade students.

Are "flavorists" or "food scientist" creating false foods?

Image: Tiia MontoCan you resist these M&Ms? If so, you may be at least partly Paleo. Many in our modern world are pulled by this and similar “foods.” Why? First let’s consider the strength of the drive leading some to consume the contents of this package. David A. Kessler, MD, former FDA commissioner writes In The End of Overeating:

My conversation with a journalist, a forty-year-old man I’ll call Andrew, reminded me that the struggle respects neither gender, nor socioeconomic class, nor age. Andrew, who is about five feet nine inches tall and weighs about 245 pounds, has written fearlessly from many of the world’s battlegrounds. He has spent time with jihadists, suicide bombers, and war-hardened soldiers, and he hasn’t flinched. But when I placed M&M’s on the table before him, Andrew felt barely able to cope.

Andrew reflects:

“I wake up in the morning knowing that food is my enemy and that I am my own enemy. It’s uncontrollable.”

In a recent story in "CBS This Morning: Saturday" psychologist Daniel Amen, argues that modern food manipulation is in the hands of "flavorists." They often design processed foods to stimulate our cravings:

"They know how to put together certain combinations of fat, sugar and salt to actually work on the heroin or morphine centers of your brain and they can be totally addictive if you are not careful."

“To battle these cravings, Amen suggests getting at least seven hours of sleep to avoid making bad food decisions; start the day with a breakfast with protein to help balance your blood sugar through the day; and avoid sugar and artificial sweeteners.”

(Sounds Paleo doesn’t it?)

However, what Amen calls "flavorists," Kessler calls "food scientists." In his book, Kessler describes how processed food is often designed to trigger the reward centers in the brain. Quoting an industry “insider,” the fast food industry is “the manipulator of the consumers’ minds and desires.”

Now, what if you block the chemical hook and leave the flavor unchanged? In a study mentioned by Kessler animals ate less chocolate following treatment with naltrexone, an opioid antagonist. “Presumably because blocking the opioid signals took away the reward value.” Thus, there is science to processed food design. Science that may make processed food better, but also science to make processed food “hedonistic.”

OK, so the fast food industry designs food to stimulate the brain’s reward centers; the greater the reward, the more we consume and purchase. Is this a satisfying answer? Why do the strong cravings overrule the conscious mind, such as in Andrew’s case, even though it is aware these foods eventually undermine our health? Amen’s suggests designer foods stimulate the same regions of our brains associated with yearning for family or friends. Discussing this with my son John Michael, he wondered if we are replacing a loss:

It is almost as though junk food is taking the place of community.

THE WEIGHT OF THE NATION, PART 2 - CHOICES

The second section of the four part series of THE WEIGHT OF THE NATION focuses upon choices that individuals can and do make that affect their weight control and ultimately their health. According to the National Institutes of Health $800Million is currently budgeted annually for research on the causes, consequences, prevention, and treatment of obesity in the U.S. best current research evidence shows that small changes in lifestyle can produce small weight loss that yields positive results for current and long term health. The National Weight Control Registry identified the following characteristics of persons who maintain a weight loss:

• 78% eat breakfast every day
• 75% weigh themselves at least once a week
• 62% watch less than 10 hours of TV per week
• 90% participate in physical activity daily

The obesity epidemic is overwhelming our resources as a nation- but we can each do our part to fix it. For more information visit Part Two, Choices.

THE WEIGHT OF THE NATION, Part One: Consequences of Obesity

By Suzanne

According to Donald Lloyd-Jones MD, Chair of Preventive Medicine, Northwestern University Feinberg School of Medicine, ideal cardiovascular health is characterized by meeting each of the following criteria:

• Optimal levels of total cholesterol
• Normal blood pressure
• Not having diabetes
• Having a lean BMI
• Not smoking
• Participating in recommended levels of physical activity
• Pursuing a healthy diet

How do you measure up?  Surprisingly, less than 1% of the United States population currently meet these criteria. A key reason: overweight and obesity affect 69% of the U.S. population. The initial one hour segment of the WEIGHT OF THE NATION focuses upon the health consequences of overweight and obesity. Together, they are creating a tsunami of chronic disease costing an additional $150 Billion in health care costs.  

See PART I here.

Related Post

THE WEIGHT OF THE NATION

THE WEIGHT OF THE NATION

By Suzanne

My first entry covers America’s number one public health problem - the obesity epidemic. It is an honor to contribute to PaleoTerran and I welcome your comments.

I was fortunate to be invited and attend a local community screening of  THE WEIGHT OF THE NATION.  This four-part presentation showcases the multi-factorial causes of the obesity epidemic in the United States and features prevention efforts that can be implemented by individuals, families, and communities at large as they combat this major public health threat.   

The film includes a discussion of human DNA and how it remains little changed from that of our hunter-gatherer ancestors.  As a species, humans are adapted for low calorie intake, increase energy expenditure, and the challenge of finding food.  Agriculture changed human social structure and created greater food security. The early 20th century witnessed an increase in food research and government subsidies resulting in increasing crop yields and surpluses.  A food economy developed with goal of maintaining a surplus.  The same technological advances that brought food surpluses created an environment favoring the development of the obesity epidemic.

The resulting impact on health and cost to our society is tremendous.  The CDC reports that 68.8% of the current population in the U.S. is either obese or overweight; obesity is essentially becoming the new norm. This new norm causes a proliferation of chronic diseases, such as diabetes, that decrease American’s life expectancies. Over $150 Billion is spent annually on the health consequences associated with obesity in the U.S.  Furthermore, the financial consequences of the obesity epidemic impact businesses by increasing health care costs, decreasing employee productivity, and increasing absenteeism.  Ultimately, in one-way or another, everyone in society is affected.

The Institute of Medicine (IOM) reviewed past success that improved national health including tobacco cessation, air quality, and water pollution and decided that action is necessary to address obesity.

You may ask: “What can I do to protect myself, my family, and my community?"  With 68.8% of our population affected, we all may know a family member, a friend, or a loved one who is either obese or over-weight.

Help spread the facts about the obesity epidemic, its impact, and how everyone can participate as change agents to promote the health of society.

Although not specifically promoting Paleo, the presentation does validate the benefits of Paleolithic nutrition. As we continue to become educated consumers, we can share the message with our families and communities. The presentation and multiple resources are freely available on the HBO web site found here.

Throughout September, I will critique each of the four sections and showcase the steps we can all take to benefit our families, friends, and communities. Paleolithic nutrition can play a role in reducing the weight of the nation.

THE WEIGHT OF THE NATION is a presentation by HBO and the Institute of Medicine (IOM), in association with the Centers for Disease Control and Prevention (CDC), the National Institutes of Health (NIH), and in partnership with the Michael & Susan Dell Foundation and Kaiser Permanente.

Cognitive decline in obesity

Obesity (a BMI of 30 or more) increases problems with memory and thinking, a condition also known as cognitive decline. Pauline Anderson, writing for Medscape Neurology MedPulseNews, notes:

It has been known for some time that obese patients face relatively fast cognitive decline, but recent research has suggested that if such patients are metabolically healthy, either naturally or through the use of medications, they may escape some adverse health effects…

However, a new study published in the August 21 issue of Neurology shows otherwise. While cognitive decline occurs faster in those with metabolic abnormalities such as high blood pressure or high cholesterol, the decline in cognitive function 10 years following baseline assessments were similar in the metabolically normal and abnormal groups. Anderson quotes study author Dr. Archana Singh-Manoux: 

We know that lower BMI is protective; that if your BMI is under 25, you have the slowest cognitive decline. So lower BMI is a good idea, but this notion that you can have a high BMI, and if your metabolic health is good, you'd be okay doesn't seem to be supported in our paper.

Related Posts

• Obesity in adults linked to cognitive dysfunction
• Getting fatter on the typical Western diet
• Rheumatoid arthritis is associated with obesity
• Did we start loosing willpower in the late 1970's?

Getting fatter on the typical Western diet

Image: Newsweek magazineGary Taubes, an Investigator in Health Policy Research at the Berkley School of Public Health, has been battling conventional wisdom regarding nutrition for years. He has delivered his message in many forums including the 2007 book, Good Calories, Bad Calories and the 2011 book, Why We Get Fat.

His most recent contribution is an article in the May 14 print issue of Newsweek: The New Obesity Campaigns Have It All Wrong. Taubes notes that conventional wisdom regarding the cause of obesity is based on the concept of “energy balance”:

At its heart is a simple “energy balance” idea: we get fat because we consume too many calories and expend too few. If we could just control our impulses – or at least control our environment, thereby removing temptation – and push ourselves to exercise, we’d be fine. This logic is everywhere…”

Unfortunately, the "energy balance" concept is failing us: 42% of American will be fat by 2030. Even NIH Director Francis Collins has difficulty explaining the failure - “We are struggling to figure this out.” Taubes has another view:

There is an alternative theory, one that has also been around for decades but that the establishment has largely ignored. This theory implicates specific foods – refined sugars and grains – because of their effect on the hormone insulin, which regulates fat accumulation. If this hormonal-defect hypothesis is true, not all calories are created equal, as the conventional wisdom holds. And if it is true, the problem is not only controlling our impulses, but also changing the entire American food economy and rewriting our beliefs about what constitutes a healthy diet. (emphasis added)

Related Posts

• Did we start loosing willpower in the late 1970's?
• Paleolithic Nutrition: Diet and Modern Disease
• The Standard or Average American Diet
• Are mainstream nutritionists beginning to recognize the value of Paleolithic nutrition?

Jet fuel & obesity

About 5 million more is spent every year in the jet fuel needed to fly heavier Americans, compared with 1960 weights.

Gary Taubs
The New Obesity Campaigns Have It All Wrong
Newsweek, May 14, 2012

Obesity in adults linked to cognitive dysfunction

Duke University and CDC predict 42% of Americans will be obese by 2030. The impact on the nation's health (and economy) will be significant. Obesity is associated with many modern diseases such as diabetes, heart disease, metabolic syndrome, and sleep apnea. Other associations include migraine headaches, increased brain pressure (pseudotumor cerebri), rheumatoid arthritis, and inflammation of the brain's frontal lobes and hypothalamus.

Obesity is measured using the Body Mass Index (BMI) and is calculated by dividing body weight by the square of the height. As noted by Medscape Neurology, BMI “is the most common means that clinicians use to define obesity.”

Central obesity, obesity of the abdomen, is also harmful to health. The extra adipose tissue collects below the skin (subcutaneous adipose tissue) and around the abdominal organs (visceral adipose tissue). While many of us grew up thinking extra fatty tissue was harmless, it is now understood that the adipose tissue of central obesity represents a “pathogenic tissue compartment” (a compartment of tissue that can make us sick).

In a study published in March 2012 issue of Age and Ageing, Dae Hyun Yoon MD, PhD and associates looked at the whether obesity, as measured by BMI, and central obesity affected brain function.

In 250 patients, 60 years of age or older, the amount abdominal fatty tissue (both visceral and subcutaneous) was measured on an abdominal CT scan and compared to the results on the MMSE-KC, a Korean diagnostic scale similar to the Mini-Mental State Examination that measures cognitive function. The researchers discovered that persons 60-70 years of age with a high BMI or high visceral obesity had significantly more difficulty with memory and thinking. According to Medscape Medical News:

After controlling for age, sex, education, hypertension, and diabetes, high BMI and being in the top tertile for visceral adipose tissue area were significantly associated with poor cognitive performance in those up to age 70 years.

Dr. Yoon explained:

Visceral adipose tissue is more metabolically active than subcutaneous adipose tissue and is thought to have a stronger influence on insulin resistance, among other things. It has long been considered as a pathogenic tissue compartment and this research shows a positive association between visceral adipose tissue area and low cognitive functioning. (emphasis added)

Contrary to popular belief, excess fat does not just sit there; it produces inflammatory substances that affect a variety of bodily functions. The extra fat impacts how the brain works; or, in this situation, doesn’t work.  

Staffan Lindberg MD, PhD, writing in his medical textbook Food and Western Disease: Health and nutrition from an evolutionary perspective, notes that “overweight was extremely rare among hunter-gatherers.” As he shows, increasing evidence is pointing to the ancestral diet as the best model for reclaiming health.

To learn more about the ancestral human diet, consider these Ancestral Diet Resources. Also, take a look at the response in BMI and central obesity of these two dedicated Paleo advocates! (Unconquerable Dave and Diana)

Go Paleo to reduce and then get rid of obesity. Keep your brain sharp.

If you are on a special diet for health reasons, discuss the Paleo diet with your doctor before making changes. Also discuss with your doctor if you have high blood pressure or diabetes since your medications may need to be lowered. Also, if you are on Coumadin or have hemochromatosis, discuss this diet with your doctor before you start.   

Rheumatoid arthritis is associated with obesity

Is the typical modern diet a factor in the development of rheumatoid arthritis? Image: iStockphotoHealth, Medical, and Science Updates reports on a Mayo Clinic research study that revealed over half of the increase in rheumatoid arthritis (RA) cases seen in women from 1985–2007 is related to the increase in obesity during that time. While “the exact nature of the link between obesity and autoimmune diseases such as rheumatoid arthritis is not clear,” the relationship to obesity suggests RA may be - at least in part – due to the typical modern diet. 

Not only is RA more common in persons with a high body mass index (BMI), according to a study by the Karolinska Institutet in Stockholm, Sweden, it is also more severe in when obesity is present. Furthermore, persons RA and obesity are more likely to have associated diseases (co-morbidities) such as "hypertension, diabetes mellitus and chronic pulmonary disease."

In a review article New York Medical College, the authors note that although RA is viewed primarily as "chronic progressive inflammatory joint disorder," the disease also affects other organ systesms: 

Cardiovascular manifestations of RA include predilection for accelerated atherosclerosis and endothelial dysfunction resulting in coronary artery disease (CAD), stroke, congestive heart failure, and peripheral arterial disease. ... Other manifestations include pericarditis, myocarditis, and vasculitis.

Although the cause of RA is unknown, dietary grains may be a factor. In medicalese, from a study by Dr. Loren Cordain and associates:

By eliminating dietary elements, particularly lectins, which adversely influence both enterocyte and lymphocyte structure and function, it is proposed that the peripheral antigenic stimulus (both pathogenic and dietary) will be reduced and thereby result in a diminution of disease symptoms in certain patients with RA.

Did we start loosing willpower in the late 1970's?

If you, or someone you know, have become obese, you may have received "friendly" advice that it is all about will power. Somehow, if you just will it, you can loose weight. After all, the problem is with you. You are either eating too much, or not exercising enough. You will likely also hear the same message from your doctor. Our food producers love this answer. Hey, if you are obese, it is not their fault. It's the lack of willpower.

As the chart above suggests, many of us must have lost our willpower in the late 1970's. That's when obesity started going up.

Although willpower is a factor in many human activities, this view of obesity simply does not ring true. The increase in the average weight of the population since the late '70s is not due to lack of willpower. It is due to the increased availability, and marking, of increasingly low-quality food and its effect on the brain. 

Thus, the solution is not more willpower, although it always helps. The solution is knowledge. The more we understand that low-quality food is becoming the overwhelming component of the typical modern diet, and, the more we understand this diet increases the likelihood of chronic diseases, the more we recognize we must make our own nutritional decisions instead allowing our culture to lead us astray.

But, how do we begin? Especially when there are so many, often contradictory, diets being recommended. We can start by trying to reproduce the diet of our ancestors. After all, those living before agriculture and animal husbandry were often taller and healthier than we are. As best as can be determined, they did not suffer from the modern chronic preventable diseases that the CDC reports currently accounts for about ¾ of healthcare spending - hundreds of thousands of years of human evolution can’t be discarded without consequences.

Its time to learn about ancestral human nutrition on our own: not an easy task. Fortunately, there are many guides to help us along the way. For those new to the ancestral diet, the next post will provide links to resources to help you get started. For those already enjoying its benefits, there is still more to learn.

Addendum: Ancestral Health Resources coming later this week.

PlosBLOGS: "The Anthropology of Obesity"

Evolutionary analysis can prove indispensable when considering endemic obesity rates – obesity can be viewed as a problem resulting from the contrast between Paleolithic genetic programming and the present-day obesogenic environment.

PlosBLOGS: Neuroanthropology just posted a bibliography on obesity arranged in the following topics: 

• Evolution and Obesity
• Biocultural Perspectives
• Social Determinants of Health
• Change in Diet
• Obesity Culture
• Health Behaviors
• Economic Influences
• Neuroanthropology Posts

Diets changed from Paleolithic times through the agricultural and industrial revolutions. With the advent of globalization it is of no surprise that change is being observed in food acquisition, consumption, and preparation patterns. Obesogenic environments are on the rise with the homogenization of diet that occurs initially with an increase in consumption of traditional food items, and the subsequent introduction of fast foods, convenience foods, and industrialized food items that are nutritionally devoid.

 This is a great post and resource. Check it out.