Tag Archives: obesity

Do Potatoes Make You Fat or Diabetic?

Researchers in Denmark say “no.” French fries, maybe.

“The identified studies do not provide convincing evidence to suggest an association between intake of potatoes and risks of obesity, T2D, or CVD. French fries may be associated with increased risks of obesity and T2D although confounding may be present. In this systematic review, only observational studies were identified. These findings underline the need for long-term randomized controlled trials.”

Source: Potatoes and risk of obesity, type 2 diabetes, and cardiovascular disease in apparently healthy adults: a systematic review of clinical intervention and observational studies

Obesity Soon to Affect Average Life Span in U.S.

That excess weight can shorten your life

That excess weight can shorten your life

“The medical community seems to be under a fog that we can constantly and forever reduce death rates, and that’s simply not true,” said Professor Olshansky, who published a study in 2012 showing that life spans for white women without a high school diploma had declined, a rare event in developed countries.

“You need to look at the health status of the living,” not the mortality statistics of the dead, he said, adding that obesity is afflicting younger generations in a way that will eventually make the numbers worse.

RTWT at The New York Times. 

Do something about your obesity before it’s too late.

Steve Parker, M.D.


Paleobetic Diet-FrontCover_300dpi_RGB_5.5x8.5

Does Pollution Cause Type 2 Diabetes?

See text for mention of pancreatic alpha and beta cells

See text for mention of pancreatic alpha and beta cells

A panel of university-based scientists convened by The Endocrine Society recently reviewed the available literature on health effects of endocrine-disrupting chemicals (aka EDCs). The executive summary is available free online. Some excerpts:

The full Scientific Statement represents a comprehensive review of the literature on seven topics for which there is strong mechanistic, experimental, animal, and epidemiological evidence for endocrine disruption, namely: obesity and diabetes, female reproduction, male reproduction, hormone-sensitive cancers in females, prostate cancer, thyroid, and neurodevelopment and neuroendocrine systems. EDCs such as bisphenol A, phthalates, pesticides, persistent organic pollutants such as polychlorinated biphenyls, polybrominated diethyl ethers, and dioxins were emphasized because these chemicals had the greatest depth and breadth of available information.

*  *  *

Both cellular and animal models demonstrate a role for EDCs in the etiology of obesity and T2D [type 2 diabetes]. For obesity, animal studies show that EDC-induced weight gain depends on the timing of exposure and the age of the animals. Exposures during the perinatal period [the weeks before and after birth] trigger obesity later in life. New results covering a whole range of EDC doses have underscored the importance of nonmonotonic dose-response relationships; some doses induced weight increase, whereas others did not. Furthermore, EDCs elicit obesity by acting directly on white adipose tissue, al- though brain, liver, and even the endocrine pancreas may be direct targets as well.

Regarding T2D, animal studies indicate that some EDCs directly target 􏰁beta and alpha cells in the pancreas, adipocytes, and liver cells and provoke insulin resistance together with hyperinsulinemia. These changes can also be associated with altered levels of adiponectin and leptin— often in the absence of weight gain. This diabetogenic action is also a risk factor for cardiovascular diseases, and hyperinsulinemia can drive diet-induced obesity. Epide- miological studies in humans also point to an association between EDC exposures and obesity and/or T2D; however, because many epidemiological studies are cross-sectional, with diet as an important confounding factor in humans, it is not yet possible to infer causality.


Bix at Fanatic Cook blog says foods of animal origin are the major source of harmful persistent organic pollutants, some of which act as ECDs.

Keep your eyes and ears open for new research reports on this critically important topic.

Steve Parker, M.D.

Book front cover

Book front cover

Theoretical Support for the Healthfulness of the Paleo Diet

See modern man walking off that cliff?

See modern man walking off that cliff?

Aren’t people healthier now, thanks to the Agricultural and Industrial Revolutions?

As a marker for health, we can look at life span and longevity. Humans started to see dramatic increases in longevity probably around 30,000 years ago, before the revolutions. Nevertheless, Kuipers, Joordens, and Muskiet note that average life expectancy after the start of the Agricultural Revolution 10,000 years ago fell from about 40 to around 20 years.

Other researchers report that average height in the Nile River Valley at the time of the transition fell by 4 inches (10 cm). The Agricultural Revolution allowed for rapid expansion of human populations through more births, but those folks still didn’t live very long. As before the revolution, infections and high infant/child mortality rates were devastating killers, dragging down average life spans. If you survived childhood, you had a shot at hitting 50 or 60.

At the dawn of the Industrial Revolution, life expectancy at birth was only 35–40 years, even in then-sophisticated cultures like Switzerland. Consider Thomas Jefferson, the principal author of the U.S. Declaration of Independence and the third U.S. president, who lived between 1743 and 1826 (he died on July 4, Independence Day). He and his wife Martha had six children; only two survived to adulthood, and only one past the age of 25. Martha died at age 33. This mortality picture was typical for the times.

Since 1800, life expectancy has doubled in industrialized countries, but it’s mostly due to public health measures and economic prosperity. Other than smallpox vaccination, it wasn’t until the mid-20th century that medical care advances contributed in a major way to longevity.

Overview: Conflict Between Our Paleolithic Genes and Modern Life

A number of diseases or conditions may result from the mismatch of our Paleolithic genes and modern lifestyle. If not caused by the mismatch, they’re aggravated by it. These are the so-called “diseases of civilization”:

  • type 2 diabetes
  • high blood pressure
  • overweigh and obesity
  • dental caries (tooth decay or cavities)
  • osteoporosis
  • fertility problems (polycystic ovary syndrome)
  • pregnancy complications (pre-eclampsia, gestational diabetes)
  • some cancers (colon, breast, prostate)
  • heart disease (such as coronary artery disease)
  • major and postpartum depression
  • autism
  • schizophrenia
  • some neurodegenerative diseases (Parkinsons disease, Alzheimer’s disease)
  • constipation
  • hemorrhoids
  • diverticulosis
"I ate well over 70 grams of fiber daily!"

“I ate well over 70 grams of fiber daily!”

Overweight and Obesity

The Paleolithic diet is lower in total carbohydrate calories compared to the standard American diet: 30-35% versus 50-55% of calories. The higher consumption today, especially of highly processed refined carbohydrates, contributes to overweight and obesity, diabetes, gallbladder disease, heart disease, and possibly dementia. Ian Spreadbury hypothesizes that carbohydrate density of modern foods may be the cause of obesity. Refined sugars and grains—types of acellular carbohydrates—are particularly bad offenders. These acellular carbs may alter our gut microorganisms, leading to systemic inflammation and leptin resistance, etc. Our Paleolithic ancestors had little access to acellular carbohydrates. Here’s how Spreadbury explains acellular: “Tubers, fruits, or functional plant parts such as leaves and stems store their carbohydrates in organelles as part of fiber-walled living cells. These are thought to remain largely intact during cooking, which instead mostly breaks cell-to-cell adhesion. This cellular storage appears to mandate a maximum density of around 23% non-fibrous carbohydrate by mass, the bulk of the cellular weight being made up of water. The acellular carbohydrates of flour, sugar, and processed plant-starch products are considerably more dense. Grains themselves are also highly dense, dry stores of starch designed for rapid macroscopic enzymic mobilization during germination. Whereas foods with living cells will have their low carbohydrate density “locked in” until their cell walls are breached by digestive processes, the chyme produced after consumption of acellular flour and sugar-based foods is thus suggested to have a higher carbohydrate concentration than almost anything the microbiota of the upper GI tract from mouth to small bowel would have encountered during our coevolution.” (Reference: “Comparison with ancestral diets suggests dense acellular carbohydrates promote an inflammatory microbiota, and may be the primary dietary cause of leptin resistance and obesity,” in Diabetes, Metabolic Syndrome, and Obesity: Targets and Therapy. 2012; vol 5: 175–189. doi: 10.2147/DMSO.S33473 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3402009/)

Added sugar provides 17 % of total energy in modern societies, contributing to overweight, obesity, tooth decay, and diabetes. Modern diets provide 15–20% of calories from protein, compared to 25–30% in the Paleolithic diet. To the extent that high protein consumption is satiating, lower consumption may cause over-eating of carbohydrates and fats, then overweight and obesity and all their associated medical conditions.

Heart Disease

I written elsewhere on the blog that the much lower omega-6 to omega-3 fatty acid ratio in the Paleolithic diet. There’s some evidence that today’s high ratio may contribute to systemic inflammation and chronic disease, heart disease in particular. Today’s ratio is quite high due to our consumption of industrial seed oils, such as those derived from soybeans, peanuts, corn, and safflower. And we don’t eat enough cold-water fatty fish, which are major sources of omega-3 fatty acids. Two long-chain polyunsaturated fatty acids, EPA and DHA, are essential fatty acids. That means our bodies cannot make them. We have to get them from diet. DHA and EPA are also cardioprotective omega-3 fatty acids.

High Blood Pressure

Most modern diets have much more sodium and much less potassium than the Paleolithic diet, perhaps contributing to high blood pressure, which in turn contributes to heart attacks, strokes, and possibly premature death. The higher magnesium content of the paleo diet may also help prevent high blood pressure.

Gastrointestinal Problems

We eat much less fiber these days, contributing to constipation, hemorrhoids, and diverticulosis. Some experts believe low fiber consumption adversely effects development of palate bones, jaws, and tooth placement.


Our lower vitamin D levels these days may cause osteoporosis (thin fragile bones) and raise the risk of diabetes and cancer. Our prehistoric ancestors spent more time in the sun, allowing their bodies to make vitamin D.

Type 2 Diabetes

Robert Lustig and associates looked at sugar consumption and diabetes rates in 175 countries and found a strong link between sugar and type 2 diabetes. It’s not proof of causation, just suggestive. From the scientific article abstract: “Duration and degree of sugar exposure correlated significantly with diabetes prevalence in a dose-dependent manner, while declines in sugar exposure correlated with significant subsequent declines in diabetes rates independently of other socioeconomic, dietary and obesity prevalence changes. Differences in sugar availability statistically explain variations in diabetes prevalence rates at a population level that are not explained by physical activity, overweight or obesity.” (Reference: Basu S, Yoffe P, Hills N, Lustig RH (2013) The Relationship of Sugar to Population-Level Diabetes Prevalence: An Econometric Analysis of Repeated Cross-Sectional Data. PLoS ONE 8(2): e57873. doi:10.1371/journal.pone.0057873)

A major diet change from Stone Age to modern diets is a reduction in magnesium consumption. This could be one reason type 2 diabetes is a problem today. A 2013 article at Diabetes Care suggests that higher magnesium consumption in modern populations may protect against type 2 diabetes (Reference: http://care.diabetesjournals.org/content/early/2013/09/23/dc13-1397.abstract.html?papetoc).

Dental Problems

Dentist John Sorrentino wrote at his blog in 2012: “The truth is that tooth decay is a relatively new phenomenon. Until the rise of agriculture roughly 10,000 years ago, THERE WAS NO TOOTH DECAY IN HUMANS. Let that sink in for a moment. Humanity is 2,500,000 years old. For the first 2,490,000 years no one ever had a cavity. If we understand that tooth decay started when people started farming instead of hunting and gathering for a living clearly you realize that tooth decay is a disease or mismatch between what you are eating and what your body expects you to eat. If we examine the past as prologue it becomes clear that the path to proper health starts in the mouth and the answers are so simple that not only did a Cave Man do it. They perfected it.” (Reference: http://www.sorrentinodental.com/blog.html?entry=why-teeth-decay-i)

To be fair and balanced, a research report from 2014 found a very high incidence of caries (cavities) in a Stone Age population living in what is now Morocco. The authors attributed the cavities to heavy consumption of acorns, which are rich in carbohydrates and sticky, to boot.

Orthodontist Mike Mew, BDS, MSc, made a presentation at the 2012 Ancestral Health Symposium titled “Craniofacial Dystrophy—Modern Melting Faces.” Dr. Mew says 30% of folks in Western populations have crooked teeth and/or malocclusion, and the mainstream orthodontic community doesn’t know why. But they’ve got expensive treatment for it! Dr. Mew thinks he knows the cause and he shared it at the symposium. The simple cure is “Teeth together. Lips together. Tongue on the roof of your mouth.” And eat hard food that requires lots of chewing, like our ancestors did, ideally in childhood before age 9. Older people also benefit, he says.

NPR (National Public Radio) in February, 2013, ran an article called “Ancient Choppers Were Healthier Than Ours,” by Audrey Carlsen. An excerpt: “Hunter-gatherers had really good teeth,” says Alan Cooper, director of the Australian Centre for Ancient DNA. “[But] as soon as you get to farming populations, you see this massive change. Huge amounts of gum disease. And cavities start cropping up.” And thousands of years later, we’re still waging, and often losing, our war against oral disease. Our changing diets are largely to blame. In a study published in the Nature Genetics, Cooper and his research team looked at calcified plaque on ancient teeth from 34 prehistoric human skeletons. What they found was that as our diets changed over time — shifting from meat, vegetables and nuts to carbohydrates and sugar — so too did the composition of bacteria in our mouths. Not all oral bacteria are bad. In fact, many of these microbes help us by protecting against more dangerous pathogens. (Reference: http://www.npr.org/blogs/health/2013/02/24/172688806/ancient-chompers-were-healthier-than-ours)

Dentist Mark Burhenne wrote the following at Huffington Post – Canada: “It is generally well accepted that tooth decay, in the modern sense, is a relatively new phenomena. Until the rise of agriculture roughly 10,000 years ago, there was nearly no tooth decay in the human race. Cavities became endemic in the 17th century but became an epidemic in the middle of the 20th century (1950). If we understand that tooth decay started when people started farming, rather than hunting and gathering, it’s clear that tooth decay is the result of a mismatch between what we’re eating and what our bodies are expecting us to eat based on how they evolved….The recent changes in our lifestyle create a “mismatch” for the mouth, which evolved under vastly different environments than what our mouths are exposed to these days. Our mouths evolved to be chewing tough meats and fibrous vegetables. Sugar laden fruit was a rare and special treat for our paleolithic ancestors. Now, our diets are filled with heavily processed foods that take hardly any energy to chew — smoothies, coffees, and sodas high in sugar, white bread, and crackers to name just a few.” (Reference: http://www.huffingtonpost.ca/mark-burhenne/paleo-diet-oral-health_b_4041350.html)

Shrinking Brains

Since the end of the Stone Age, human brain size has been shrinking. That’s not good, is it? Anthropologist John Hawks has noted that over the past 20,000 years, the average volume of the human male brain has decreased from 1,500 cubic centimeters to 1,350 cc, losing a chunk the size of a lemon. The female brain has shrunk proportionately. Anthropologists don’t know why. Is it modern nutrition? The experts aren’t sure what it means for our future. As for me, I think the answer is in Mike Judge’s movie, “Idiocracy.”

His brain was bigger than yours

His brain was bigger than yours

Death By Sugar

Sugar-sweetened beverages kill almost 200,000 worldwide annually, according to a Gitanjali Singh, Ph.D., a postdoctoral research fellow at the Harvard School of Public Health. How could that be? Sugar-sweetened beverages contribute to obesity, which in turn leads to diabetes, cardiovascular disease, and some cancers. (Reference: Singh, GM, et al “Mortality due to sugar-sweetened beverage consumption: A global, regional, and national comparative risk assessment,” American Heart Association Epidemiology and Prevention/Nutrition, Physical Activity and Metabolism 2013 Scientific Sessions, Abstract EPI-13-A-879-AHA.) Reducing consumption of sugar-sweetened beverages was one of the major points in the American Heart Association’s 2010 guidelines for reducing heart disease.

Elderly Cognitive Impairment

Diets high in sugar and other carbohydrates raise the risk of elderly cognitive impairment, according to recent research by the Mayo Clinic. Mild cognitive impairment is often a precursor to incurable dementia. (Most authorities think dementia develops more often in people with diabetes, although some studies refute the linkage.) Researchers followed 940 patients with normal baseline cognitive functioning over the course of four years. Diet was assessed via questionnaire. Study participants were ages 70 to 89. As the years passed, 200 of them developed mild cognitive impairment. Compared with those eating the lowest amount of sugar, those eating the most sugar were 1.5 times more likely to develop cognitive impairment. Looking at total carbohydrate consumption, those eating at the highest levels of carbohydrate consumption were almost twice as likely to develop mild cognitive impairment. The scientists note that those eating lower on the carbohydrate continuum were eating more fats and proteins. (Reference: Mayo Clinic website, published October 16, 2012 http://www.mayoclinic.org/news2012-rst/7128.html)

Is a Paleolithic-Style Diet the Healthiest Way to Eat?

Certified paleo-compliant, plus high omega-3 fatty acids

Certified paleo-compliant, plus high omega-3 fatty acids

The jury’s still out on that one! My strong sense is that it’s definitely more healthful than the Standard American Diet. Maybe the traditional Mediterranean diet or DASH diet is even healthier. Don’t hold your breath waiting for the randomized controlled trials that would answer the question definitively.

If the paleo diet is the healthiest, which version is best? That’s a question for another day (or year).

The most healthful diet for you depends on your genetic make-up and any medical conditions you have.

Steve Parker, M.D.

Paleolithic Diet May Help Reduce Risk of Obesity

…according to a basic science study published in the British Journal of Nutrition. The mechanism for reducing obesity risk would be increased satiety. We’ve seen that before with the paleo diet as compared to a Mediterranean-style diet. Disappointingly, the researchers didn’t see any paleo diet benefits in these healthy study participants in terms of glucose and insulin metabolism.

I haven’t read the report, don’t have it, don’t know when I’ll read it.


There is evidence for health benefits from ‘Palaeolithic’ diets; however, there are a few data on the acute effects of rationally designed Palaeolithic-type meals. In the present study, we used Palaeolithic diet principles to construct meals comprising readily available ingredients: fish and a variety of plants, selected to be rich in fibre and phyto-nutrients. We investigated the acute effects of two Palaeolithic-type meals (PAL 1 and PAL 2) and a reference meal based on WHO guidelines (REF), on blood glucose control, gut hormone responses and appetite regulation. Using a randomised cross-over trial design, healthy subjects were given three meals on separate occasions. PAL2 and REF were matched for energy, protein, fat and carbohydrates; PAL1 contained more protein and energy. Plasma glucose, insulin, glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic peptide (GIP) and peptide YY (PYY) concentrations were measured over a period of 180 min. Satiation was assessed using electronic visual analogue scale (EVAS) scores. GLP-1 and PYY concentrations were significantly increased across 180 min for both PAL1 (P= 0·001 and P< 0·001) and PAL2 (P= 0·011 and P= 0·003) compared with the REF. Concomitant EVAS scores showed increased satiety. By contrast, GIP concentration was significantly suppressed. Positive incremental AUC over 120 min for glucose and insulin did not differ between the meals. Consumption of meals based on Palaeolithic diet principles resulted in significant increases in incretin and anorectic gut hormones and increased perceived satiety. Surprisingly, this was independent of the energy or protein content of the meal and therefore suggests potential benefits for reduced risk of obesity.

Steve Parker, M.D.

Reference: Bligh H.F., et al. British J Nutr. 2015 Feb 28;113(4):574-84. doi: 10.1017/S0007114514004012. Epub 2015 Feb 9.
Plant-rich mixed meals based on Palaeolithic diet principles have a dramatic impact on incretin, peptide YY and satiety response, but show little effect on glucose and insulin homeostasis: an acute-effects randomised study.

Short-Term Paleo Diet Improves Glucose Control in Obese Type 2 Diabetes (the Masharani Study)

UCSF is here

UCSF is here

A three-week Paleolithic-style diet improved blood sugars and lipids in obese type 2 diabetics, according to researchers at the University of California—San Francisco. This is the Lynda Frassetto study I’ve been waiting over a year for. The first named author is U. Masharani, so I’ll refer to this work in the future as the Masharani study. Sorry, Lynda.

To understand the impact of this study, you need to know about a blood test called fructosamine, which reflects blood sugar levels over the preceding 2–3 weeks. You may already be familiar with a blood test called hemoglobin A1c: it tells us about blood sugars over the preceding three months. Blood glucose binds to proteins in our blood in a process called glycation. The higher the blood glucose, the more bonding. Glucose bound to hemoglobin molecules is measured in HgbA1c. Glucose bound to plasma proteins (predominantly albumin) is measured as fructosamine. It probably has nothing to do with fructose. Fructosamine is a generic name for plasma ketoamines.

If you’re doing a diabetic diet study over over 2–3 weeks, as in the report at hand, changes in glucose control will mostly be detected in fructosamine rather than HgbA1c levels.

How Was the Research Done?

Twenty-five obese diabetics in the San Francisco Bay area were randomly assigned to either a paleo-style diet or one based on American Diabetes Association (ADA) guidelines. They followed the diets for three weeks, with various measurements taken before and after intervention.

Participants were aged 50-69; you have to guess the sex breakdown. Average body mass index was 34. Over half (63%) were White/European American; there were three each of Asian, African American, and Hispanic ethnicity. They had normal blood pressures and diabetes was well controlled, with hemoglobin A1c’s around 7% and fructosamine levels close to normal. Four subjects were on no diabetes medications; 14 were taking metformin alone, five were on metformin and a sulfonylurea, one was on long-acting insulin and a sulfonylurea. No drug dosages were changed during the study.

Both intervention diets were designed for weight maintenance, i.e., avoidance of weight loss or gain. If participants lost weight, they were instructed to eat more. All food was prepared and provided for the participants. Three meals and three snacks were provided for daily consumption.

Fourteen subjects completed the paleo diet intervention. They ate lean meats, fruits, vegetables, tree nuts, poultry, eggs, canola oil, mayonnaise, and honey. No added salt. No cereal grains, dairy, legumes, or potatoes. Calorie percentages from protein, fat, and carbohydrate were 18%, 27%, and 58%, respectively. Compared to the ADA diet, the paleo diet was significantly lower in saturated fat, calcium, and sodium (under half as much), while higher in potassium (twice as much). These dieters eased into the full paleo diet over the first week, allowing bodies to adjust to higher fiber and potassium consumption. The paleo diet had about 40 grams of fiber, over twice as much as the ADA diet.

[I wonder why they chose canola over other oils.]

Ten subjects completed the ADA diet, which included moderate salt, low-fat dairy, whole grains, rice, bread, legumes, and pasta. Calorie percentages from protein, fat, and carbohydrate were 20%, 29%, and 54%, respectively (very similar to the paleo diet). I don’t have any additional description for you. I assume it included meat, poultry, eggs, and fruit.

Diet compliance was confirmed via urine measurements of sodium, potassium, pH, and calcium.

What Did the Researchers Find?

Both groups on average lost about 2 kg (4-5 lb).

Compared to their baseline values, the paleo group saw reductions in total cholesterol, HDL cholesterol, LDL cholesterol, HgbA1c (down 0.3% absolute reduction), and fructosamine. Fructosamine fell from 294 to 260 micromole/L. [The normal non-diabetic range for fructosamine is 190-270 micromole/L.]

Compared to their baseline values, the ADA diet group saw reductions in HDL cholesterol and HgbA1c (down 0.2% absolute reduction) but no change in fructosamine, total cholesterol, and LDL cholesterol.

Comparing the groups to each other, the difference in fructosamine change was right on the cusp of statistical significance at p = 0.06.

Within each group, insulin resistance trended down, but didn’t reach statistical significance. However, when they looked at the folks who were the most insulin resistant, only the paleo dieters improved their resistance. By the way, insulin resistance was measure via euglycemic hyperinsulinemic clamp instead of the short-cut HOMA-IR method.

Blood pressures didn’t change.

The authors don’t mention hypoglycemia at all, nor alcohol consumption.

They note that some of the paleo dieters complained about the volume of food they had to eat.


I found what I think are a couple misprints. Table 1 has incorrect numbers for the amount of sodium and potassium in the ADA diet. See the text for correct values. Table 2 give fructosamine values in mg/dl; they should be micromoles/L.

Final Thoughts

This particular version of the paleo diet indeed seems to have potential to help control diabetes in obese type 2’s, perhaps even better than an ADA diet, and despite the high carb content. Obviously, it’s a very small study and I’d like to see it tested in a larger population for several months, and in type 1 diabetics. But it will be years, if ever, before we see those research results. Diabetics alive today have to decide what they’ll eat tomorrow.

I wish the researchers had explained why they chose their paleo diet macronutrient breakdown: calorie percentages from protein, fat, and carbohydrate were 18%, 27%, and 58%, respectively. Perhaps they were trying to match the ratios of the ADA diet. But from what I’ve read, the average ancestral paleo diet carbohydrate energy percentage is 30-35%, not close to 60%. My experience is that reducing carb calorie consumption to 30% or less helps even more with glucose control. Reducing carbs that low in this study would have necessitated diabetes drug adjustments and increased the risk of hypoglycemia.

The authors wonder if the high fiber content of the paleo diet drove the lowered glucose levels.

High HDL cholesterol is thought to be protective against coronary artery disease and other types of atherosclerosis. Both diet groups here saw reductions in HDL. That’s something to keep an eye on.

The ADA diet group saw a drop in HgbA1c but not fructosamine. I can’t explain how HgbA1c goes down over three weeks without a change in fructosamine level.

You have to wonder if the paleo diet results would have been more impressive if the test subjects at baseline had been sicker, with poorly controlled blood pressures and HgbA1c’s of 9% or higher. And it sounds like some of these folks would have lost weight if not forced to eat more. The paleo diet is more satiating than some.

The article was well-written and a pleasure to read, in contrast to some I’ve suffered through recently.

Steve Parker, M.D.

Reference: Masharani, U., et al. Metabolic and physiologic effects from consuming a hunter-gatherer (Paleolithic)-type diet in type 2 diabetes. European Journal of Clinical Nutrition, advance online April 1, 2015. doi: 10.1038/ejcn.2015.39

Is Estrogen Poisoning the Cause of the Obesity Epidemic?

Eating too much tofu?

Too much tofu?

James P. Grantham and Maciej Henneberg of the School of Medical Sciences (University of Adelaide, Adelaide, Australia) suggest that estrogen-like compounds in the environment are causing obesity. Read about their hypothesis in PLOS One. I don’t know if they’re right, but their idea deserves consideration.

A couple estrogen-like substances they mention are in soy and polyvinyl chloride (PVC). We ingest these xenoestrogens. I had not been aware that soy consumption is positively linked to obesity.

The authors don’t instill confidence by using weak references such as #22.

I didn’t see the trendy “endocrine disruptors” moniker in the article.

Read the whole enchilada.

Steve Parker, M.D.

This Just In! Obesity Reduces Lifespan

I'm worried about the kid's future health

I’m worried about the kid’s future health, too

MedPageToday has the details. A quote:

In a computer modeling study, very obese men lost just over 8 years of life compared with normal-weight men, and very obese women lost as many as 6 years, Steven Grover, PhD, of McGill University, and colleagues reported online in the Lancet Diabetes and Endocrinology.

They also found that very obese men and women (defined as a body mass index [BMI] of 35 and higher) lost about 19 years of healthy life, defined as living free of chronic disease such as diabetes and cardiovascular disease.

Note that “very obese” in this context has a specific definition: body mass index 35 or higher. Calculate yours.

The number of life years lost to obesity and disease were highest for those who were very obese in young adulthood and presumably stayed obese for years. In other words, becoming very obese at age 25 is more threatening than onset 60.

I first got interested in weight loss in the 1990s when I had an office-based primary care medical practice. It was obvious that many of the medical problems I was treating were related to years of obesity. Believe me, you’re much better off preventing those problems via diet and exercise.

Click for The Lancet study abstract.

Steve Parker, M.D.

How Did the Agricultural and Industrial Revolutions Change Human Diets?


With the advent of the Agricultural Revolution 10,000 years ago, mankind took a giant leap away from two million years of evolutionary adaptation. The Industrial Revolution that started in the late 18th century—about 240 years ago—was yet another watershed event. The Agricultural Revolution marks the end of the Old Stone Age and the start of the Neolithic period. The Neolithic ended four to six thousand years ago, replaced by the Bronze Age (or Iron Age in some areas).


The Agricultural Revolution refers to farming the land on a large scale, and all that entails: gathering and planting seeds, nurturing the soil, breeding plants for desirable traits, storing crops, processing plants to maximize digestibility, domesticating wild animals and enhancing them by selective breeding, setting down roots in one geographic location, etc. The revolution allowed for the expansion of reliable food supplies and an explosion of human populations. Less time was needed for hunting and foraging, allowing for the development of advanced cultures.

It wasn’t all sunshine and roses, however. We have evidence that human health deteriorated as a result of the revolution. For instance, some populations declined in height and dental health.


The Industrial Revolution starting in the late 18th century brought its own changes to our diet. Progressive industrialization and affluence changed the composition of our “energy foods.” For instance, peasants in poor developing countries derive about 75% of their calories from high-fiber starchy foods. With modernization, fiber-free fats and sugars become the source of 60% of calories. U.S. consumption of cereal fiber decreased by 90% between 1880 and 1976. In addition to lower fiber content, refined wheat products also had fewer vitamins and other micronutrients. Machinery allowed the production of margarine and vegetable oils. Sugar imports and snacking increased in the Western world.

Obesity suddenly became very common in the upper classes of Europe and England toward the end of the 17th century and even more so in the 18th. Weights also increased throughout populations of developed countries. For instance, if we look at U.S. men of average height between the ages of 30 to 34, average weights were 148 lb (66 kg) in 1863, but were up to 170 lb (77 kg) in 1963. Our current obesity epidemic didn’t even start until around 1970.

Let’s look at a few major U.S. diet changes from 1860 to 1975. Energy derived from protein rose from 12% to 14–15%. Energy from fat rose from 25 to 42% of calories. Energy from starches fell from 53 to 22%. Calories from sugar rose from 10 to 24%. Total carbohydrate calories fell from 63 to 46%.

It only takes a few decades to see major changes in a population’s food consumption. For instance, U.S. per capita consumption of salad and cooking oils increased from 21.2 pounds per person in 1980 to 54.3 pounds per person in 2008 (USDA data). I refer to these oils as industrial seed oils, and they include soybean, corn, and sunflower oil. We’re not entirely sure what effect these have on health. Some suspect they are related to obesity, heart disease, and other “diseases of civilization.” Per capita soybean oil consumption in the U.S. increased over a thousand-fold between 1909 and 1999, to 7.4% of total calories. It’s in many of our processed foods. Linoleic acid is a predominant omega-6 fatty acid in seed oils. Linoleic acid consumption increased by 200% in the last century. Thanks to increasing omega-6 fatty acid consumption, the omega-6/omega-3 ratio increased from 5.4:1 to 9.6:1 between 1909 and 2009. (Reference: Blasbalg TL, Hibbeln JR, Ramsden CE, Majchrzak SF, Rawlings RR. “Changes in consumption of omega-3 and omega-6 fatty acids in the United States during the 20th century.” Am J Clin Nutr. 2011 May;93(5):950-62. doi: 10.3945/ajcn.110.006643. Epub 2011 Mar 2.)

The Industrial Revolution also introduced into our diets large amounts of man-made trans-fats, which are highly detrimental to cardiovascular health. Public outcry has lead to diminishing amounts of dietary trans-fats over the last decade.

An occasional teaspoon of sugar probably won't hurt you

Added sugars: table sugar in coffee, high-fructose corn syrup in ketchup

At his Whole Health Source blog, Dr. Stephan Guyenet and Jeremy Landen produced a graph of U.S. sugar consumption from 1822 to 2005. Dr. Guyenet wrote, “It’s a remarkably straight line, increasing steadily from 6.3 pounds (2.9 kg) per person per year in 1822 to a maximum of 107.7 pounds (49 kg) per person per year in 1999. Wrap your brain around this: in 1822, we ate the amount of added sugar in one 12 ounce can of soda (360 ml) every five days, while today we eat that much sugar every seven hours.” Note that added sugars overwhelmingly supply only one nutrient: pure carbohydrate without vitamins, minerals, antioxidants, protein, fat, etc.


Think about the typical Western or Standard American Diet (SAD) eaten by an adult these days. It provides an average of 2673 calories a day (not accounting for wastage of calories in restaurants; 2250 cals/day is probably a more accurate figure for actual consumption). Added sugars provide 459 of those calories, or 17% of the total. Grains provide 625 calories, or 23% of the total. Most of those sugars and grains are in processed, commercial foods. So added sugars and grains provide 40% of the total calories in the SAD. That’s a huge change from the diet of our prehistoric ancestors. Remember, we need good insulin action to process these carbohydrates, which is a problem for diabetics. Anyone going from the SAD to pure paleo eating will be drastically reducing intake of added sugars and grains, our current major sources of carbohydrate. They’ll be replacing them with foods that generally require less insulin for processing. (Figures are from an April 5, 2011, infographic at Civil Eats: http://www.civileats.com.)

FUN FACTS! (from the U.S. Dept. of Agriculture)

  • A typical carbonated soda contains the equivalent of 10 tsp (50 ml) of table sugar.
  • The typical U.S. adult eats 30 tsp (150 ml) daily of added sweeteners and sugars.
  • U.S total grain product consumption was at record lows in the 1970s, at 138 pounds per person. By 2008, grain consumption was up by 45%, to 200 pounds per person.
  • Total caloric sweetener consumption (by dry weight) was 110 pounds per person in the 1950s. By 2000, it was up 39% to 150 pounds.
  • Between 1970 and 2003, consumption of added fats and oils rose by 63%, from 53 to 85 pounds. (How tasty would that be without starches and sugars? Not very.)
  • In 2008, “added fat” calories in the U.S. adult diet were 641 (24% of total calories).

Steve Parker, M.D.

Pollution May Be Causing T2 Diabetes and Obesity

It sounds like Jerome Ruzzin is convinced that’s the case. I put some thought into it last August and was skeptical—still am, but I’m keeping an open mind. Mr. Ruzzin has a review article published in 2012 at BMC Public Health (“Public health concern behind the exposure to persistent organic pollutants and the risk of metabolic diseases”). Here’s his summary:

The global prevalence of metabolic diseases like obesity and type 2 diabetes, and its colossal economic and social costs represent a major public health issue for our societies. There is now solid evidence demonstrating the contribution of POPs [persistent organic pollutants], at environmental levels, to metabolic disorders. Thus, human exposure to POPs might have, for decades, been sufficient and enough to participate to the epidemics of obesity and type 2 diabetes. Based on recent studies, the fundaments of current risk assessment of POPs, like “concept of additive effects” or “dioxins and dl-PCBs induced similar biological effects through AhR”, appear unlikely to predict the risk of metabolic diseases. Furthermore, POP regulation in food products should be harmonized and re-evaluated to better protect consumers. Neglecting the novel and emerging knowledge about the link between POPs and metabolic diseases will have significant health impacts for the general population and the next generations.

Read the whole enchilada.

The cold-water fatty fish I so often recommend to my patients could be hurting them. They are major reservoirs of food-based POPs.

Steve Parker, M.D.