Last week we discussed our rising obesity epidemic, why it is important to all of us to consider, what are some of its causes and what are some of its effects.  This week we will pick up the discussion with a broader consideration of the social context of the issue.

So where are we socially as Americans in our relation to food?  We have largely forgotten how to cook or eat together.  We snack all day long, especially at work and from vending machines.  We use the drive-thru regularly for meals with their increasingly large portion sizes.  We quench our thirst with quarts of sugary or alcoholic beverages.  We rely increasingly on the freezer case at the supermarket for complete meals. Regular mealtimes are a thing of the past.

Researchers have found some interesting demographic trends that are perpetuating our epidemic.  Basically, obesity begets obesity.  Americans are having kids at an older age.  Kids of older moms tend to be larger at birth and stay larger through life.  Moms who are obese tend to have larger babies.  Older babies tend to be heavier moms.  Obese moms tend to have more children than thinner moms.  An interesting effect in dating and marriage.  Obese folks tend to attract each other.  Children of obese parents tend to become obese.  If one parent is obese there is a 50% chance a child will become obese, 80% if both parents are obese.  All of this increases obesity and the obesity genes in our population.

Basically, obesity in America perpetuates obesity.  We are coming to understand the biology of this effect.  Folks who are obese become insulin resistant.  This means that glucose levels in the blood build up.  This glucose is taken in by the liver and turned to fat.  Obesity also leads to leptin resistance.  Leptin is the hormone our fat cells secrete to tell the brain that we have plenty of fat and we should stop eating.  But at a certain point, the brain basically goes deaf to those messages and no longer hears the “stop eating” message.  Endocrine disruptors are also disrupting these messages.  We are also fundamentally changing the flora of bacteria in our large intestines with these changes in diet over time.  We are now learning the important nutritional effects these are having that tend to push the fat building mechanisms of the body.

So back to our question.  Is there blame to be placed?  It is easy to blame McDonalds and school lunch programs.  It is easy to blame the box of Krispy Kreme on the counter at work or vending machines full of snacks or social media.  Schools don’t have gym classes anymore or my town doesn’t have a playground for my kids.  TV shows have too many ads.  All those drink companies put too much sugar in their drinks, and nobody gets enough sleep.  We can blame farm subsidies to corn farmers.  And don’t get me started on processed foods with all those preservatives and chemicals.  Believe it or not, we are actually living in great times in relation to food availability.  In the 1950s about 25% of family income went to food.  Today it is just over 10% and half of that is now getting spent outside the home at restaurants and the like.

This is clearly larger than one obese person.  It is hard to blame Mary or Beth or Joe or Frank for their obesity when we look at all these forces at work around us.  We need to work very hard not to stigmatize folks caught in these cyclical conditions.  The causes are clearly larger and seem embedded in our culture and our environment.  Heck, almost 40% of adults are obese and another 30% are overweight.  That means that normal weight folks are the minority. Be careful who you insult.

We are surrounded by these cultural and environmental influences that are so pervasive as to be almost invisible.  But they have this huge impact on us.  So, I want to slow down a bit and think about what we mean when we talk about culture and a cultural influence.

I did a lazy thing.  I looked up “culture” online.  Here is a nice definition that I found. 

Culture (/ˈkʌltʃər/) is an umbrella term which encompasses the social behavior and norms found in human societies, as well as the knowledge, beliefs, arts, laws, customs, capabilities, and habits of the individuals in these groups.

Culture is really hard to think about in the abstract.  It is like looking in the mirror and asking is this how I look to other people?  Is this really how others see me?  If we want to talk about our American culture, it is almost too big to grasp.  Americans are so different.  Ages, ethnicities, parts of the country, urban, rural, recent immigrants, different religions.  That said, what if we asked how Americans are different from Europeans or South Americans?  In comparison with other groups, we might have a way to draw some generalizations about what we Americans have in common.

So, we have this American culture that we can barely define, but we observe that those who live in that culture have been getting progressively more overweight over the last 60-70 years or so.  This has occurred across the whole range of Americans from the Arctic Circle in Alaska to Key West in Florida.  So, what do we have that makes our American culture, those social behaviors and norms, so prone to obesity?  Back to our definition. Culture is the knowledge, beliefs, arts, laws, customs, capabilities, and habits of the individuals in these groups.  So, culture is the accumulation of all us individuals.  We are each part of and saturated with our American culture.  Think about a concert.  You pay to go to see and hear a great band.  You contribute, literally contribute, money to an expression of American culture in the concert.  But then you walk out grooving on the great music with your friends, having absorbed and been saturated with some specific aspect of American culture.  So, is this culture something that we inherit or something that we create?  Clearly, we absorb it as we grow up.  Clearly, we like parts and dislike other parts.  Obviously, it is some of both inherited and created, but we don’t have to pass on the culture we inherited.

Blame

So, we have an obesity-prone culture.  Where is the blame if any for our obesity prone culture?  We inherited this culture.  We enjoy this culture.  We fight with parts of this culture.  How do we participate in this culture?  With all of us in thousands of micro decisions we make every day.  Who bought the 2-liter soda for the apartment?  Who knows that lady at the Wendy’s drive thru on a first name basis?  Who doesn’t even own a frying pan or a whisk or know how to make mac and cheese from scratch?  Who doesn’t have a single fruit in the house, but always carries 3 granola bars in their backpack?  Who took the bus instead of walking that 1-mile commute, or binged on some stupid show all weekend instead of getting outdoors?

There are hundreds of small ways to change our personal cultures.  A bag of apples instead of a box of Krispy Kremes.  Speaking out when the next Farm Bill comes up in Congress.  Do we really need to go to the all-you-can-eat buffet tonight?  How about lingering a little longer in the produce aisle next time you are in the grocery store and less in the frozen dinner section?  Get a rice cooker.  Make brown rice.  It is amazingly easy.  Why are you really staying up to midnight, or 1 or 2 or 3, binging on some show?

The marketplace responds to our vote with our dollars.  How can we blame big companies when we eat their food and drive through their drive-thru windows?  They are only doing what we want.  I’m sure there would be helpful public policies and regulations that would be helpful, but what drives the companies to develop the products they do?  Our insatiable appetite does.  General Mills would love nothing more than to keep making the same old Corn Chex cereal for the next century and take in a comfortable profit on a low sugar breakfast cereal.  But us fickle consumers keep changing our demands and forcing them to change flavors and take out high fructose corn sugar (for no reason, but that’s another story) and make it gluten-free.  We play this rather odd game of make-me-happy but then we blame them when they add more sugar or salt or lower the fiber or add flavor enhancers with fancy names.  Now don’t get me wrong, there is plenty of blame to go around, but we as consumers should own our share.

So, who is to blame for our 60-year climb into obesity?  Our culture, yes.  But remember that we are all our culture and we all can change that culture.  We have met the enemy, it is fat and it is us, all of us.

So, what can we do about our problem?  Well, one thing we shouldn’t do is go on a diet in the usual sense.  Dieting in America is one of the hardest things imaginable.  All the forces, cultural and physiological, are arrayed against you.  What is needed is a healthier and more long-term perspective. 

Here are some lifestyle suggestions that can change our individual cultures and may contribute to a change in our American culture.  I am partially drawing from two interesting sources.  A Psychology Today article from 10 years ago nicely diagnosed our social causes of obesity with some suggestions for change.  The NY Time just completed a January series called the Eat Well Challenge.

• Am I really hungry?  We are regularly assaulted by food messages telling us to consume.  If you ate less than 2 hours ago, you are probably not actually hungry, even as you are looking hard at that doughnut right now.  If we stick closer to actual mealtimes for eating, this gets easier.
• How long have I been on my phone?  Was it really necessary?  Phone and screen time does two things.  It makes us eat mindlessly and it keeps us from being active.
• How about a smaller plate?  Portion sizes have increased over the last 50 years.  We can reverse this if we choose, by simply choosing a smaller plate or bowl or glass or by ordering one size smaller than usual at the drive-thru.
• Does it have to be that sweet?  Our drinks are all sweet now, and some are astonishingly sugary.  It is easy to recommend just water, but even just looking at the label for something with half the sugar of your usual would be a great step in the right direction.
• Did I enjoy every bite? Slow it down, put down the fork between bites.  Why the hurry?  Is eating a chore or a charm?  Mindful eating is a wonderful habit to cultivate.
• Can I cook that?  One of the things we have lost is kitchen literacy.  But cooked food is family food. It is food we talk about and share.  Start simple with a few recipes.  Get the basic tools needed.  Also, as suggested above, get a rice cooker.  
• How about another veggie?  Instead of removing some no-no food, just add another veggie to the table.  
• But my diet?  Is the point being healthy or losing weight?  Obviously the two are connected but being healthy will lead to weight loss that stays.
• Am I a hungry shopper?  You will be in a hurry and will tend to buy more snack food and less fruit.
• Fruit and veggie check.  Do you have more fruits and vegetables in the refrigerator or more snack food on the counters?
• Am I sleep cheating?  Anything less than 7 hours is cheating yourself.  What screen time should you give up?

Conclusion

The United States, and in fact most of the world, has an obesity problem that is increasing.  It is costing us a lot in terms of disability, disease, deaths, and dollars.  It is too simple and actually rather misinformed and wrong to point to overweight people as the ones to blame.  It turns out that we are all to blame because it is deeply embedded in our culture and our economy that we ended up this way.  We all actually really really like this obesity-prone culture with its low-cost drive-thrus and tasty snacks and sugary drinks.  The miracle is that all of us aren’t obese.  The good news is that since we are our culture, then we all have a vote.  We can buy apples instead of fruit roll ups and we can stay home and learn how to cook a real stew instead of another evening at the all-you-can-eat buffet.  This would be a win for healthy kids, healthy culture, and maybe even a few lost pounds.  So, buy a whisk and google “homemade mac and cheese” and change the world.

We have an obesity epidemic in our country, in case you hadn’t noticed.  Over two thirds of American adults are overweight or obese.  But why should we be concerned about this in the middle of a COVID pandemic?  Here’s why.  Obesity and its cousins diabetes and hypertension are three of those “comorbidities” that are causing people to die from COVID when they might have otherwise survived.  Also, when this pandemic is over, the epidemic and its costs and consequences will still be with us.

I would like us to look hard at what are the causes of this epidemic and consider where some of the blame can be placed.  This may help us in finding a way out.  In this first part we will look at the scope of the problem and how we got here.  In the second part next week we will look at the larger social context and some solutions.

It is difficult to place a starting date on the problem but if we put a stake in at about 1960, then we have had a problem for about 60 years.  At that time about 13% of adults were considered obese.  This would be a body mass index, a ratio of weight to height, over 30.  By 2018, it is now about 42% of Americans in that category and about 30% in the overweight groups with a BMI between 25 and 30.  As a real-life example, for a person 5’8” tall, obesity starts at 197 lbs by this definition.  America has seen a 3-fold increase in this category in the past 60 years. Childhood obesity has also risen.  For children above 6 years old, since the early 1960s the obesity rate has risen from about 4% to nearly 20%.  

Obesity is not evenly spread.  About 50% of Blacks are obese; 42% of Whites are obese, 45% of Hispanics, and 17% of Asian Americans are obese.  We also vary by state, with Mississippi having about 70% more obesity than Colorado.  A more complex picture of obesity emerges when considering sex and race.  Among White men there is little difference in the obesity rate across income groups.  But among Hispanic and Black men and especially among all races of women, obesity is more prevalent among poorer SES classes.  The same basically holds true for education levels, with college educated women of all races having lower prevalence.

Obesity costs about $117 billion a year in direct and indirect costs, about half of that paid by taxpayers.  About 100,000 deaths in the US per year can be attributed to obesity.  The cost of obesity to our nation now exceeds that of smoking.

Dieting, as many of us know, is a lost cause, unless you are in the dieting business.  The global market for dieting products and services has grown to about $255 billion this year.  Of course, this includes the thousands of diet books available, diet foods that one can purchase, drugs one can take, supplements that are available, groups one can pay to join, and counseling one can receive. And probably over two thirds of folks who successfully lose weight will regain it in five years.

History

So, we Americans are in quite a pickle, but it wasn’t always this way.  We are familiar with the sin of gluttony.  Back when sins were sins this was serious business.  In certain societies obesity and gluttony were associated.  This was not true for every society and every era.  In Europe when class structure was more rigidly in place, it was expected that higher classes would be heavier and have fairer skin.  Both of these traits were associated with not being in the sun working all day and having generous quantities of rich foods.  Famous paintings of nudes from the time show women that would be considered rather large by today’s anorexic standards.  And in some non-European cultures, these perceptions of overweight and obesity in women still persist, including certain Arab cultures, in parts of Africa, and in certain Pacific Island cultures.

How did we get here?  You may be familiar with the concept of calories in and calories out.  If more calories go in as food than come out as physical activity, then weight is gained.  While there is indeed truth in this thermodynamic balance, there are factors inside and outside the body that have driven the dramatic increase in obesity over the last 60 years.  As we parse out apparent causes, we have to think about things that have actually changed over that time period.

Causes

Let’s start with two examples.

Genes.  We are now in the genomics age with the full library of the human genome and we have been able to identify at least 76 genes whose mutations can contribute to obesity.  So, are genes responsible for the obesity epidemic?  We humans have had basically the same genes for the past 10,000 years or so including these various obese-prone mutations, and yet we are only getting fluffier in the past century.  While we can show that folks with more of these mutations have a higher risk of obesity, there are still plenty of folks with lots of obese mutations that are normal weight.  These mutations might best be called obesity susceptibility mutations.  They only turn on the fat when they meet various internal cues that are facilitated by external factors like lifestyle and environment.

My second example- diet.  Has this changed over 60 years?  Yes, in fact it has.  Caloric intake has increased from 2880 kcal in 1961 to 3600 kcal in 2013, a 24% increase.  This corresponds to roughly 100 kcal of meat, 100 kcal of sugar, 175 kcal of starchy foods, and 400 kcal of vegetable oil used in snacks and other prepared foods.

Most food in 1960 was home cooked, had less sugar and salt, and few people ate out, especially at fast food restaurants.  Many families ate together.  Today, families rarely eat together, often eat out, and often eat pre-packaged foods and a lot more snack foods and sugary drinks.  Where we eat, what we eat, and how we eat have all changed.  Is it any surprise that our weights have changed?

Then there are factors in our environment that have changed.  Our pharmacies are dispensing many more diabetes medicines, antidepressants, antipsychotics, and antihypertensives.  Many of these are known to increase weight, not only by their direct effect but also because they put us in better health and better moods.

We are sleeping less than in the past, between one and two hours a night and with much more shift work.  Epidemiologic and experimental work has shown that sleep deprivation adds pounds.

We are exposed to more endocrine disruptors.  These are chemicals that benefit us in some way but have been shown to have untoward effects on health including weight gain.  These include flame retardant polybrominated diphenyl ether (PBDE), and the plasticizer bisphenol A (BPA) and phthalates, DEET the bug repellent, and dioxins.

Air conditioning has increased since the 1960s.  In a counterintuitive way, bringing our homes to a steady 70 degrees or so year-round actually burns less calories.

We all have more screen time than in the past.  In the 60s it was a grainy black and white screen with 13 channels if you were lucky.  Now we have multiple devices for multiple purposes.  Our children spend 5-7 hours a day watching screens big and small.  Research has shown a clear link with obesity.  While watching screens, we are all less likely to be paying attention to the snacking we are doing.  We call this mindless eating.  We are also clearly not outdoors being active.  We are not eating home cooked meals with the family.  Kids see more food commercials and tend to have less sleep and more disrupted sleep.

Now for our diets.  Since 1950 we have consumed about 18% less fiber.  Since the early 1800s we have steadily increased our sugar intake by over a half a pound a year every year.  We now consume about 120 lbs per year or about 1/3 lb per day.  Most of this is in snacks and beverages.  It is amazing to walk into a convenience store and see the huge array of drinks and snacks available.

This problem has come on us slowly.  We can’t really remember a time when half the people we meet in the mall or on the street were too large to be healthy.  We don’t think it is unusual to walk into a gas station/convenience store and find it wall-to-wall with junk food.  Heck, when did gas stations and convenience stores first get married?  When did the size of McDonald’s drinks start to creep up?  We are surrounded by an obese culture that we are immune to.  Next week we will talk about this culture, where it comes from and what to do about it.

I went to my dermatologist last week for my yearly checkup, an experience almost as pleasant as my semiannual trip to the dentist.  I got checked over and we had a distracting conversation while he did his thing.  On the way out he gave me some paper instructions and an interesting flier that is the topic of this post.  I have attached it below.  It is titled SUNSCREEN RECOMMENDATIONS and has this recommendation, “Boone Dermatology Clinic recommends daily sunscreen use for all patients over the age of 6 months.  We recommend a broad-spectrum sunscreen with a minimum of SPF30.”  It is important to notice how inclusive this is: everyone over 6 months with no exceptions, broad spectrum for all wavelengths, a SPF30 so that it is a complete blockage, and daily use with no exception for season or weather or time of day.  This apparently means all day.  Here is my problem with this statement as a nutritionist.  This pretty much guarantees that all their patients will be vitamin D deficient.

Here is what pretty much any textbook will tell you about vitamin D.  We get most of it from the sun.  It is called the sunshine vitamin for a reason and is barely even a vitamin in the usual sense.  The same UV radiation that gives you sunburns allows you to make vitamin D in your skin.  But any SPF greater than about 6 completely blocks vitamin D synthesis in the skin.  We only get the right UV from the sun between about 10AM and 3PM.  All latitudes north of about 35 degrees (think Atlanta, Georgia) is too far north to get sufficient vitamin D from our usual exposure to the sun.  Most Americans get almost no vitamin D from the sun in the winter both because the sun is too low and because we are so covered up.  Just imagine what this says about the vitamin D status of Canadians.  About 15 minutes in the full summer sun with bare arms and face will give most folks enough vitamin D for most of a week.  As a rule of thumb, if you aren’t worried about getting a sunburn, then you aren’t getting vitamin D.

Vitamin D deficiency is surprising common around the world, with about a billion people affected.  People who tend to stay out of the sun, people with darker skin, people north of Atlanta, and older people are all affected.  There is a threshold for sun exposure.  A sunbather on a sunny day in January in Boston could stay out all day and apart of the frost bite, would gain no vitamin D benefit. [1]  But, a White person exposing only arms and legs, thinks short and a tee, need only stand in the Texas sun for 15 minutes for all the vitamin D for a couple weeks.  A Black person would take about three times as long.

Now my dermatologist will counter that it would be so much easier and safer if we all just took a vitamin D supplement, and this is true.  So, the full recommendation is to slather every citizen every day all day with sunscreen and also take a vitamin pill every day.  How about this as an alternative?  Don’t worry about the sun for 3 seasons of the year if you live north of Atlanta.  In the summer, wear comfortable clothes and wait 15 minutes (if you are White and longer if you are Black) before putting on sunscreen in exposed areas. Easy to remember and will save you gallons of sunscreen.

The real issue here is the balance between the risks of melanoma, a very lethal skin cancer that is greatly enhanced by excess UV exposure, and the risks associated with vitamin D deficiency.  Yes, the risks of melanoma are real.  Recent data show that in the US there are about 106,000 cases annually with about 8,000 deaths.  This makes it the 12^th most lethal cancer in the country.  Compare this to lung cancer with 235,760 cases and 131,880 deaths.  In contrast to the effect of UV rays on melanoma, research has shown a strong possible role for vitamin D deficiency in breast cancer risk.  A recent meta-analysis combining 22 studies showed that women with vitamin D deficiency had 91% increased odds of having breast cancer.  Those that said they took supplements had a 3% decreased risk.  So much for supplements. [2]  In fairness, another similar study of supplements and breast cancer mortality showed a 14% reduction with vitamin D supplements. [3]  The same study showed no effect on overall mortality. Others have found roles for vitamin D in possibly preventing colon cancer[4], prostate cancer[5], and lung cancer.[6]  If vitamin D can reduce the risk of these four big killers by only a small fraction, this might easily balance the effect of UV on melanoma.  A recent meta-analysis of vitamin D clinical trials suggests that supplements may cause about a 20% reduction in overall cancer mortality. [7]

Now this may sound like I am an apostle of vitamin D.  Not so.  I have been around the field of Nutrition long enough to see things come in and out of vogue.  Vitamin D was hot when we nutritionists and many in the general public thought it would prevent or cure everything from lupus to hangnails.  That day has passed and a more sober view is setting in.  Notice that I did not make any claims for vitamin D and COVID or for immune function.  These are rather dubious claims.  Even the 20% cancer reduction that I quoted above has been challenged. [8]

So, should we slather and supplement or just delay slathering and only in the summer?  From the public health perspective, I think delaying in the summer is the better message because it has the added advantage of getting people outdoors where they can play, exercise, breath fresh air and lower risk of COVID. Some have suggested that insufficient sunlight is responsible for about 400,000 deaths per year in the United States. [9]  While I personally think this may be an overestimate, it is interesting to compare this to the 8000 known melanoma deaths per year and the slather and supplement regimen my dermatologist recommends to prevent them.

Looks like I may need to have a talk with my dermatologist.

References

1. Hollis, B.W., Circulating 25-Hydroxyvitamin D Levels Indicative of Vitamin D Sufficiency: Implications for Establishing a New Effective Dietary Intake Recommendation for Vitamin D. The Journal of Nutrition, 2005. 135(2): p. 317-322.

2. Hossain, S., et al., Vitamin D and breast cancer: A systematic review and meta-analysis of observational studies. Clin Nutr ESPEN, 2019. 30: p. 170-184.

3. Zhang, Y., et al., Association between vitamin D supplementation and mortality: systematic review and meta-analysis. Bmj, 2019. 366: p. l4673.

4. Mahendra, A., et al., Vitamin D and gastrointestinal cancer. J Lab Physicians, 2018. 10(1): p. 1-5.

5. Trump, D.L. and J.B. Aragon-Ching, Vitamin D in prostate cancer. Asian J Androl, 2018. 20(3): p. 244-252.

6. Wei, H., et al., Associations of the risk of lung cancer with serum 25-hydroxyvitamin D level and dietary vitamin D intake: A dose-response PRISMA meta-analysis. Medicine (Baltimore), 2018. 97(37): p. e12282.

7. Manson, J.E., S.S. Bassuk, and J.E. Buring, Principal results of the VITamin D and OmegA-3 TriaL (VITAL) and updated meta-analyses of relevant vitamin D trials. J Steroid Biochem Mol Biol, 2020. 198: p. 105522.

8. Manson, J.E., et al., Vitamin D Supplements and Prevention of Cancer and Cardiovascular Disease. N Engl J Med, 2019. 380(1): p. 33-44.

9. Alfredsson, L., et al., Insufficient Sun Exposure Has Become a Real Public Health Problem. Int J Environ Res Public Health, 2020. 17(14).

A Nutritionist’s Perspective

First, a quick preamble. This is the first in what I hope will be a series of posts on food and nutrition.  This essay was adopted and updated from a talk I gave three years ago on my campus at Appalachian State University in Boone, NC.  I had great help from my graduate student at the time, Drew Hilton, in preparing this material.

I want to talk about diets and some of the problems with undertaking one to lose weight.  To make this more interesting and applicable I have decided to discuss three popular diets and to draw lessons from them that can be applied to all diets.  The diets I have chosen are generally considered fad diets and are not generally recommended by dietitians.  That will heighten the lessons we can draw.  I will try to be objective about the pros and cons of these diets.

A word of caution here.  I am not a Registered Dietitian, nor do I pretend to be able to prescribe specific foods and diets to specific people.  I am an expert in the biochemistry of nutrition and metabolism, and I tend to see diets from that perspective.  So, let’s get started.

I have chosen three diets to draw lessons from, the paleo diet, the keto diet, and the gluten-free diet.  Many people would call these “fad diets” because they tend to be out of favor with nutritional experts and their popularity waxes and wanes, but they still remain popular with many people today.  We will address them one at a time.  My goals here are not to discredit every diet out there or completely discourage you from undertaking a diet if you need.  I hope to give some sensible advice riffing off these diets that many of my readers have already tried.First though, why are so many people dieting?  America has been in an obesity epidemic for about the last 70 years.  And we have seen the consequences in rising cases of diabetes and hypertension and many other chronic diseases.  People are constantly worried about their weight.  About 43% of teenage girls admit to being recently on a diet. Dieting is a $43 billion industry with videos, supplements, books, mail order foods, and medications for dieters. A search for “diet books” on Amazon brings up 60,000 hits.  Recent research showed that half of all diet advertisements had at least one false claim.  Here is one of my favorites.  And for all of that, only about 5% of dieters are successful in keeping the weight off.

The Paleo Diet

The paleo diet is a diet loosely based on what our paleolithic ancestors may have eaten.  It eliminates dairy, grains, sugar, legumes, processed oils, salt, alcohol, coffee, and most processed foods. There was growing interest in the 80s and 90s, but Loren Cordain’s book The Paleo Diet in 2002 established the diet as a national phenomenon. The rationale is that we are evolutionarily adapted best to a diet prior to the development of agriculture in the Neolithic age.  Hence, agriculturally developed foods such as grains, dairy and sugar are discouraged on this diet.  If we return to this diet we will avoid the modern degenerative diseases- heart disease, diabetes, and cancers.  Characteristics of an ideal paleo diet include higher protein, lower carbs, higher fiber, higher unsaturated fats, higher potassium, alkaline load, and higher vitamins, minerals, antioxidants, and phytochemicals.  Prohibited foods include cereal grains, legumes, dairy, refined sugar, potatoes, processed foods, refined vegetable oils, and salt.  Promoted foods include grass-fed /free-range meats, fruits and vegetables, fish/seafood, eggs, nuts/seeds, and healthful oils (olive, walnut, avocado, coconut, etc.).  Obviously, the paleo diet tends to cost more than the usual western diet.

Here are some of the errors that I see in the philosophy underpinning the paleo diet.  We have a rather rudimentary understanding of what paleolithic people ate, but what we know for sure is that by that time humans were all over the world and eating all kinds of foods.  There is no single paleolithic diet.  Another wrong assumption is that the human genome has not changed or evolved since then and since the advent of agriculture.  One simple counterexample is the advent of lactose tolerance in some folks, allowing for the common practice of drinking milk.  This probably came about in more than one place by a genetic mutation about 10,000 years ago.  Also erroneous is the simple assumption that the foods our ancestors ate are the same ones available in the supermarket.  What our ancestors might have called “corn” or “carrots” bear almost no resemblance to those products today.  A true paleo diet would be almost inedible to the modern consumer.  Finally, the paleo adherent gives no credit to the marvelously flexible human digestive physiology.  Consider all the diets that currently exist around the world that humans thrive on.  We are truly a wonderfully omnivorous and adaptive species that seems to be able to do rather well on almost any diet.  My apologies here to my dietitian friends who are cringing at the thought of all their well-crafted dietary recommendations being subverted.

All that said, I’m not suggesting that you will die a short terrible death on the paleo diet.  Let’s take a quick look at some scientific studies.  There aren’t many of these, but we can draw some conclusions.  In a study titled, “Long-term effects of a Palaeolithic-type diet in obese postmenopausal women: a 2-year randomized trial”, the researchers ran a trial in which they trained half of the subjects to prepare a paleo diet and half a healthy control diet.  They concluded that, “A Palaeolithic-type diet has greater beneficial effects vs a [control diet] regarding fat mass, abdominal obesity and triglyceride levels in obese postmenopausal women.”  In another more comprehensive study titled “Paleolithic nutrition for metabolic syndrome: systematic review and meta-analysis” the authors summarized the results from four studies, “The Paleolithic diet resulted in greater short-term improvements in metabolic syndrome components than did guideline-based control diets.”

So, these studies support the benefits of the paleo diet as a weight loss diet that improves our lab numbers.  While this is encouraging for paleo enthusiasts, it is not surprising.  Restrictive diets tend to result in weight loss.  Also, diets that can decrease hunger pains are also helpful.  We know that foods higher in protein and fats tend to be satiating, meaning the eater feels full longer.  This diet and the keto diet both are higher in protein and fat than the normal western diet.  If I suggested a diet to you that removed all grains that began with the letters W and S and all vegetables and fruits and began with C and G, you would lose weight, if only because you would spend half your day in the grocery store, trying to figure out what not to eat.  The question I would pose to purveyors of these diets is whether the success is in the story they tell or the restrictions they impose.

Secondly, almost any diet that results in weight loss almost invariably results in improved metabolic scores.  This often puzzles the critics.  How can a high fat diet result in lower blood cholesterol levels or lower blood pressure?  It happens because the high fat diet is more satiating and results in weight loss that results in healthier cholesterol and blood pressure. 

So, is the paleo diet safe?  Three thoughts.  Safe compared to what diet?  First of all, we know that the standard American diet, shared by many around the world, is not exactly the epitome of perfect nutrition.  For starters, it has too much sugar, not enough fiber, is low in some key minerals and has way too much salt.  So, compared to that diet, many diets are better.  But compared to a healthy vegetarian diet, I would vote for the veggies.  Two, at what weight?  One topic I am not addressing here is who should be on a diet and why.  It would be (and might be someday) a topic for a series of blogs.  Let me say simply that the risks associated with obesity go up with weight and the benefits of weight loss and being on any diet that works go up with weight.  For normal weight folks, I would take you back to the faulty assumptions and the numerous restrictions and ask you to consider a more enjoyable and healthier alternative.  Finally, consider the cost.  For the extra cost you are giving up beans, beer, and bread.

The Keto Diet

Having covered some of the common issues, these next two diets will go more quickly.  First is an issue with names.  The original ketogenic diet was a true medical diet that was quite extreme, with up to 90% of energy coming from fat and protein compared to the usual 50%.  It was used successfully to treat children with refractory epilepsy.  The so-called “Keto Diet” in modern use is nowhere near that in proportions.  Most keto diets are low-carbohydrate diets with about 20-30% compared to the usual 50-60% carbs.  The most famous of these diets is the Atkin’s Diet, named after the famous doctor who invented it.

These diets are very popular and much scientific research has been published on them.  One major study titled “Very-low-carbohydrate ketogenic diet v. low-fat diet for long-term weight loss: a meta-analysis of randomized controlled trials” summarized 13 clinical trials of 12 months or longer.  They found, “Overall, 37% dropout rate. Average 37% carbs, Keto diet had 0.91 kg greater weight loss, lower triglycerides, diastolic BP, and LDL and higher HDL.”  Several points to make here.  There is always a high dropout rate from weight loss studies.  Weight loss is hard and keeping people in the studies is hard.  Note the high carbs at 37%.  This is not all that restrictive.  Note the marginal benefit of 0.91 kg, about 2 lbs for the keto groups.  The benefits to triglycerides, blood pressure, LDL, and HDL, were equally small.

The physiology of the keto diet is intriguing and deserves some attention.  The basic idea is that if we can lower the incoming carbohydrates, then we can lower the blood glucose levels.  This will have specific benefits for people tending towards or in diabetes.  If the body gets low in blood glucose, which it absolutely needs to fuel the brain, then it has a backup system called ketogenesis.  In ketogenesis a group of metabolites call ketone-bodies can be produced from fats when sugars, like glucose, are in low supply.  Keto enthusiasts will emphasize at this point that burning up fat is what dieting is all about, so this state called ketosis and being fueled by ketone bodies is a good state to be in.  But the body still sees it as an emergency state, not the preferred state.  As an analogy, imagine working in a building where the fire alarm was sounding about half the time.

Is the keto diet safe?  Three concerns.  Based on the physiology I just described, certain folks should be concerned.  Folks who can run into super low blood glucose levels should beware of this diet.  That would include folks with diabetes who are on glucose controlling drugs such as insulin.  These ketone bodies, in high enough concentration can be acidic.  There is a small risk of ketoacidosis.  This takes us back to the original definition of the keto diet and the question of just how restrictive of carbs the diet is.  With moderate carbs at 30-40%, there is going to be little ketosis.  At low carbs of 10-20%, ketosis will be frequent.  When ketones are high and glucose is low, the brain says, “Hungry.”  This doesn’t sound all that pleasant.  So, what is the quality of life here, especially given the increased cost again, and the restrictive diet.  Remember, no doughnuts, drinks, or Doritos.  As stated before, any benefits we see from this diet are more than likely due to the restrictions that lead to modest weight loss that lead to healthier lab numbers.

Gluten-free diet

Gluten is a protein in 3 grains: wheat, barley, and rye.  It is also found in processed foods such as soy sauce, salad dressing, food starch, beer, etc..  The diet was first developed for people with celiac disease, an autoimmune disease that affects the intestine and slowly blocks absorption of nutrients.  Untreated leads to death from malnutrition.  Here is an interesting full disclosure for my readers.  I have celiac disease.  I have been diagnosed for about 12 years.  While there are inconveniences to be sure, it is one of the least troublesome autoimmune diseases to have.

The fad diet we know today largely developed in the early 21st century with books Grain Brain and Wheat Belly, condemning wheat and other grains as bad for health.  People started diagnosing themselves with “non-celiac gluten sensitivity” and popularizing gluten-free diets for many health benefits.  The medical profession has been puzzled by this new condition and has slowly recognized it.  Gluten-free products are now a $15 billion food industry.

There is now a cross-over between gluten-sensitivity and the FODMAP diet and Crohn’s disease and irritable bowel syndrome.  Common symptoms include abdominal pain, bloating, and gas.  This is a very complex topic.  Suffice it to say that Crohn’s and irritable bowel are both mystifying intestinal conditions that are difficult to treat and may be diet related and may be related to the carbohydrates in the diet.  Gluten may be mixed up in there somewhere.  Others have suggested gluten-free diets as possible cures for schizophrenia, fibromyalgia, and endometriosis.  These have been largely disproven.

Gluten-free diets have not been taken up as often as the other diets for weight-loss.  To the extent that they have and to the extent that studies have followed up, it appears that the results follow our previously established wisdom that restricting a diet for any reason often means less calories, which generally means weight loss and improved number.  But if you are restricting wheat, you must imagine a diet that restricts donuts, cakes, and most office treats.  Imagining losing weight on that diet is not too hard.

Please allow me just a minute to elaborate on the common errors found in the popular book Wheat Belly.  Many of the benefits of eliminating wheat are due to weight loss, not to some toxic properties of wheat.  The book has many testimonials, but few clinical trial results.  While the author will point to the dangers of various constituents of foods, none of the dangerous properties were unique to wheat starches or proteins.  The author claims that dramatic changes to the gluten content of wheat varieties has happened over time, especially since the Green Revolution of the 50s and 60s.  However, recent research has clearly shown that no changes in wheat composition has occurred.  The connections between a large number of diseases and wheat are completely unproven.

Here are some concerns that nutritionists have about gluten-free products currently on the market.  They tend to be lower in fiber than their glutenous alternatives.  They are not necessarily fortified with B vitamins and iron.  They often contain more salt, fat, and sugar.  They tend to be more than two times as expensive.

Overall Conclusions

We have seen some common threads through these three diets.  Let me summarize those for you here:

• Most fad diets won’t hurt in the short-term.
• Most diet benefits come from restrictions that lead to weight loss.
• Long-term adherence is hard and may not be as helpful as one would like.
• They are almost always more expensive.

If these three diets are not recommended in the long-term, what makes a good diet?  Here are some common-sense suggestions:

• One you can stay on for a lifetime
• That is balanced and minimally restrictive
• That lowers metabolic syndrome and other disease risk factors
• That moderates weight slowly

Best Diets Overall

Best Diet Advice from author Michael Pollan

My favorite food and nutrition author is actually not a nutritionist.  He is a journalist who has written several thoughtful books on the subject.  At the end of one of his books he give this advise for a good diet.

• Eat (whole) foods
• Not too much
• Mostly from plants