“Prove all things, hold fast to that which is good”– 1 Thessolonians 5: 21
This will be a brief commentary on the absurdities upon which many popular diet programs are based. The claims on the surface sound great. These claims sell books. The claims are parroted by coworkers and family members. The claims however are rich in rhetoric and low in evidence in most cases. A little common sense applied to their shallow logic reveals the absurd nature of many popular diet program claims.
Most people realize that something is broken with the standard American diet (abbreviated “SAD” in the literature, how fitting!). Americans struggle with obesity and obesity related illnesses. According to the CDC, nearly 40% of Americans in the U.S. are obese (CDC.gov, 2018). Obesity contributes to development of illnesses such as diabetes, heart disease, premature deaths, certain cancers and as such, also places tremendous burdens on the health care system.
With most people agreeing there is a problem, there is no shortage of persons ready to cash-in with homegrown solutions. Some far out theory, some sexy marketing, appearances on daytime T.V. programs and there you have it, the next big thing until the next, next big thing, comes along. Meanwhile, America’s obesity problem continues to worsen.
For an evidence-based diet supported heavily by scientific literature, see my post exploring the evidence on plant-based diets. The evidence clearly favors a plant-based diet for most of us living in the first-world modern era. Those advocating for plant-based diets frequently are equally prone, however, to making their case based on rhetoric as opposed to science.
Without further ado, here are some of the bizarre yet common appeals made for diets:
The meat and animal protein enthusiast: “Eat this way, because its how our paleolithic hunter-gatherer ancestors ate. ”
Oh, ok, makes sense. For most of human history, humans ate a certain way, and so therefore, we should eat that way as well. Sounds good, except for our modern lifestyle has essentially nothing in common with our ancestors. (Contradicting paleo diet claims, true modern hunter-gatherers living traditional hunter-gatherer lifestyles actually eat a diet that is 72% plant based, with only 14% of their diet consisting of protein!! (Brouns, 2018). They also have the lowest level of chronic illness of any population studied to date (Brouns, 2018)).
Should we eat like our ancestors? Are you exposed constantly to the elements, such as either continuous intense heat free of air conditioning (summer or the tropics) or sleep in cold, drafty homes or tents heated by poorly conducting fireplaces or less? Do you hike over great distances, then kill your food and process it by hand ALL THE TIME? Rain, shine, fall, winter, spring, summer? Are you exposed repeatedly to days with no food at all? Do you pack up your belongings, tear down camp, carry everything then set up camp somewhere else as you follow migratory patterns?
Truth is, we actually do not know much about how often our ancestors feasted or experienced famine (Berbesque, Marlowe, Shaw, & Thompson, 2014). Instead, all kinds of assumptions are made. Berbesque et al. (2014) notes that modern hunter-gatherer societies do not necessarily reflect the experience of ancient humanity as many of them have been pushed to more resource-poor territories by stronger, wealthier societies in recent history.
Jared Diamond has lived with modern hunter-gatherer tribes and describes his experiences inside his books. In the book, The World Until Yesterday (2014), (available here):
he notes that indigenous people find it amusing and even off-putting regarding how frequently modern first world humans eat within a day. In his book he describes how after everyone ate breakfast, the tribe was surprised when westerners not much later decided it was time to eat lunch. They were somewhat amused. When supper rolled around they were just plain annoyed with these constantly-eating visitors! (Diamond, 2014).
Diamond (2014) describes a day where they hiked an entire day through highlands forest and mountains and had no food, including when they established camp that night. Instead of being angry at him, the New Guineans treated the situation like just another day. Certainly, such fasting or long periods of time even within a single day between meals (intermittent fasting) has been linked to health benefits such as lower diabetes rates and potentially lower cancer rates (Anton et al., 2018).
In other words: You are not your ancestor, you are not a hunter-gatherer. And unless society totally collapses, be thankful you do not have to live like them. If you want their diet to produce the same effects for you (what are those effects anyway?–life expectancy certainly is not longer in these societies as noted by Diamond, 2014), you might as well match their activity levels, fasting frequencies, heat and cold exposures…or maybe you could just see what works for actual modern day people according to the science.
The Vegan Enthusiast: “Humans are not ‘evolved’ or designed to eat meat“–or “it is unnatural for us as a species to eat meat”:
There is actually a lot of science supporting plant-based diets for modern day people living modern day lifestyles. I might suggest the evidence I came across largely supports SOME very small amounts of animal products (see my evidence at a glance post on plant-based diets and also edible insects). As noted above, the healthiest population of humans studied in terms of low levels of chronic illness were a mostly plant-based hunter-gather society (Brouns, 2018). With science on the side of plant-based enthusiasts, there is no need to appeal to bizarre or historically inaccurate claims.
For example, similar to the paleolithic hunter-gatherer arguments, arguments are made by plant-based diet enthusiasts that we evolved from essentially plant-eating species and therefore, meat consumption is new and unnatural for our bodies. In a podcast I listened too, a vegan enthusiast noted that no human child would reach out and try to eat a live chicken, but would try to eat a brightly colored plant item like a fruit or berry–thus proving that eating meat is not inherent in our nature.
However, if indeed meat consumption was so unnatural, it seems strange to me that ancient humans frequently wiped out entire local bird and animal populations shortly after settling into new lands through heavy hunting and consumption–and of course habitat destruction (Diamond, 2005). Further, when settling new areas or lands, people frequently brought along animals such as pigs and chickens and other animals with the express purpose of raising them for food. This happened literally all over the world (Diamond, 2005). For such an unnatural process, meat consumption seems to be pretty universal in archaeological and anthropological research.
As noted above: just because meat consumption is relatively universal among ancestral human groups does not mean it is optimal nowadays. For example, just one serving of meat per week was correlated with an increased risk of diabetes (Vang, Singh, Lee, Haddad, & Brinegar, 2008 as cited in Olfert, & Wattick, 2018). Meat consumption has also has been associated with increased cardiovascular risk (Harland & Gartland, 2016). However, intermittent fasting patterns where 12 or more hours routinely pass between meals have been shown to reduce such risk factors (Anton et al., 2018).
As such, it appears under modern conditions plant-based diets improve health outcomes, but it is unclear under pre-modern circumstances that meat was ALWAYS bad for people. In fact, many modern chronic diseases are absent in indigenous populations despite their eating meat (Brouns, 2018; Diamond, 2014). There again, however, indigenous populations are exposed to longer and frequent fasting periods, far greater physical demands, and continuous exposure to the elements. If you are reading this post, chances are, these conditions do not apply to you.
“Diets” as Opposed to Lifestyle Changes
Many people successfully stick to vegetarian diets or plant-based diets their entire life or after switching, for the remainder of their life. Indeed, many people in the original research sites for the world’s healthiest populations ate very little meat or animal products their entire lives. According to a meta-analysis combining 12 research studies, nearly 70% of people that change their lifestyle to a plant-based lifestyle stay with the change over time (Turner-McGrievy, Mandes, & Crimarco, 2017).
Even when people “cheat” on their vegetarian or vegan diet lifestyle, their weight loss remains significantly greater than their meat eating peers over time, and their fruit and vegetable intake remains substantially higher (Turner-McGrievy, Mandes, & Crimarco, 2017).
Keto diets and low carb diets on the other hand provide short term weight loss and improved insulin sensitivity (as do plant based diets) but are difficult to adhere to with time (Brouns, 2018). Unlike plant-based diets, long term safety and health impacts of keto diets are unknown (Brouns, 2018). In fact, there is research showing that low carbohydrate diets and keto diets are low in fiber, micronutrients, and can lead to vascular inflammation, elevated homocysteine, vascular stiffness, organ damage and cancer risk increases!!!!! (Brouns, 2018).
Food/ Diet/ Health “Mediums”
Some diet trends are so bizarre they barely deserve comment. Sciencebasedmedicine.org does a nice take-down of this disappointing and delusional profiteering trend. But hey, celebs like it, so it must be real, right?
So what is right?
Instead of appealing to mythical proto-humans that ate pure plant-based diets or to ancient ancestor hunter-gatherer societies for which no real applicable research exists for modern-day humans, why not replicate what already has been shown to work now, among modern humans? Bluezones.com sought to do just that (no I am not an affiliate–though after examining the research, the science on health and diet seems right in line with the premises of their organization). Why do people in Okinawa, Japan, or Seventh Day Adventists in California, or those in Ikaria, Greece seem to live longer on average and age with less ailments than say, most Americans?
Realistically, we are not going to hunt and gather all year long without any regard of the elements. Nor are we going to traverse miles of wild terrain again regardless of the elements establishing camps as a way of life. We are not going to live in poorly heated, extremely drafty homes that run closer to outdoor temperature levels in the winter time. Most of us are going to have more than one meal per day. You will not find most of us going routinely a day or two with no food.
So our conditions are different than in the past. Why not see what actually works now, as demonstrated already by current, modern populations with lifestyles and diets that are a little more realistic/ feasible/ adaptable for the average, working modern person? What a radical, (absurd?) idea!!!
Keto? Just Say No!: A look at what the research shows for those that follow Keto/ Keto-related diets
Plant-based Diets: Fears & Answers: A research-packed post to address fears, myths, and biases people have concerning plant-based diets, providing answers to many of the common misconceptions
Evidence at a Glance: Plant-Based Diet Benefits: A quick overview of the research-backed benefits provided by plant-based diets
Anton, S. D., Moehl, K., Donahoo, W. T., Marosi, K., Lee, S. A., Mainous, A. G., 3rd, … Mattson, M. P. (2018). Flipping the Metabolic Switch: Understanding and Applying the Health Benefits of Fasting. Obesity (Silver Spring, Md.), 26(2), 254–268. doi:10.1002/oby.22065
Berbesque, J. C., Marlowe, F. W., Shaw, P., & Thompson, P. (2014). Hunter-gatherers have less famine than agriculturalists. Biology letters, 10(1), 20130853. doi:10.1098/rsbl.2013.0853
Brouns, F. (2018). Overweight and diabetes prevention: is a low-carbohydrate-high-fat diet recommendable? European Journal of Nutrition, 57(4), 1301–1312. https://doi-org.lopesalum.idm.oclc.org/10.1007/s00394-018-1636-y
CDC.gov. (2018). Adult obesity facts. Retrieved from https://www.cdc.gov/obesity/data/adult.html
Diamond, J. (2005). Collapse: How Societies Choose to Succeed or Fail. New York, NY: Viking Press
Diamond, J. (2014). The World Until Yesterday. New York, NY: Viking Press
Harland, J., & Garton, L. (2016). An update of the evidence relating to plantbased diets and cardiovascular disease, type 2 diabetes and overweight. Nutrition Bulletin, 41(4), 323–338. https://doi-org.lopesalum.idm.oclc.org/10.1111/nbu.12235
Olfert, M. D., & Wattick, R. A. (2018). Vegetarian Diets and the Risk of Diabetes. Current diabetes reports, 18(11), 101. doi:10.1007/s11892-018-1070-9
Turner-McGrievy, G., Mandes, T., & Crimarco, A. (2017). A plant-based diet for overweight and obesity prevention and treatment. Journal of geriatric cardiology : JGC, 14(5), 369–374. doi:10.11909/j.issn.1671-5411.2017.05.002