In the blog, The Latest Nutrition Trends: From A to Z, we briefly reviewed some of the common nutrition trends that we often hear of while working in healthcare. The benefits of eating a healthy diet, maintaining a healthy weight, and engaging in regular physical activity are fully supported by medical evidence and something I am sure we all encourage regularly. However, how our patients accomplish these goals can vary widely and as nurses we want to make sure we can “speak the same language” as our patients when discussing nutrition and become aware and knowledgeable about what is out there in respect to diet and nutritional trends. In this blog, we will review the Paleolithic Diet and the Whole30 program. An important definition to be aware of in discussing diet trends and programs, is the term “macronutrient.” Macronutrient refers to carbohydrates, fats and proteins, as opposed to micronutrients which refers to vitamins and minerals. Some diets may recommend a different macronutrient composition or ratio. Both the Paleolithic or Paleo diet (also called the caveman diet) and the Whole30 program recommend macronutrient intake ratios that diverge from what is recommended in the Dietary Guidelines for Americans (2015) which promotes the “adoption of healthy eating patterns characterized by higher consumption of fruits, vegetable, and whole grains and lower intake of calories, saturated fat, sodium, refined grains and added sugars” and has largely moved away from recommending specific macronutrient ratios on a daily basis.

Paleo Diet

The Paleolithic Diet or “Paleo Diet” is named in reference to the Paleolithic Era (2.5 million to 10,000 years ago) during which a hunter-gatherer approach was the primary means of nutrition. This era predates the agricultural revolution that brought traditional farming and the introduction of dairy, legumes, and grains into our diet. During this era, diabetes, heart disease and obesity were not prevalent. Those that support this diet postulate it provides a nutritional and macronutrient composition for which we were genetically and biologically programmed to tolerate and suggest that with the advent of farming, our diets evolved too quickly, and our “gut” did not adapted effectively to tolerate the modern diet.

Nutritional intake on the Paleo Diet consists primarily of meat (ideally lean, grass-fed), fish, most fruits, most vegetables, sweet potatoes, seeds, nuts (except peanuts which are actually legumes), ghee (clarified butter), healthy fats (avocado/olive oil), natural sugars (stevia, maple syrup, and honey are allowed), spices, and some seasonings. Foods that should be avoided on this diet are grains, legumes (beans, lentils, peanuts, peas), corn, white potatoes, cereals, dairy (except ghee), all processed foods, all refined sugars, artificial sugars, alcohol, and added salt.   

Although limited, there are studies evaluating the effects of the Paleolithic diet on chronic health conditions common in the United States (US). In a 2015 review of four randomized controlled trials comparing the effects of a Paleolithic Diet to a national dietary guideline-based diet on metabolic syndrome, Manheimer et al. found short-term improvements in metabolic syndrome measures, specifically waist circumference, triglycerides, blood pressure, HDL, and fasting blood glucose. Insulin resistance and metabolic syndrome are closely linked and are significant risk factors for diabetes and cardiovascular disease. The typical American diet can induce insulin resistance and inflammation (Gregor et al. 2011), therefore, in reducing insulin resistance and metabolic syndrome, at least short-term, it can be deduced that the paleolithic diet has positive effects on health.

So, what’s the bottom line? Although there are short-term benefits of the Paleolithic diet, studies on the long-term benefits for sustained weight loss and health risk reductions are limited. Furthermore, the restrictive nature of this diet places one at risk for low intake of calcium, vitamin D, thiamin, riboflavin and iron. The diet also lacks legumes and whole grains which have known health benefits. Another consideration is in those with diabetes on insulin, these patients could be at risk for hypoglycemia when sugar and carbohydrate intake is significantly reduced, therefore insulin adjustments should be made with healthcare provider involvement. Lastly, it can be difficult to maintain a restrictive diet long-term. 

Whole30

Another similar program, the Whole30 program, developed in 2009 by a nutritionist, has similar dietary intake recommendations as the Paleo Diet but the objective of initiating the diet is different. The objective of the Whole30 program is to “reset” the body by eliminating all potentially pro-inflammatory foods that could exacerbate chronic conditions. This is essentially an elimination diet. The founders suggest that many of the eliminated foods including dairy, sugars, grains and legumes are responsible for increased inflammation, gut disruption, hormone imbalances, psychological conditions, skin conditions, immune conditions, and allergies. The foods that are allowed on the Whole30 diet are meat (ideally lean, grass-fed), fish, most fruits, most vegetables, seeds, sweet potatoes, nuts (except peanuts which are actually legumes), coffee, ghee (clarified butter), vinegar, spices/seasonings, and minimal amounts of fruit juices as sweeteners. Also allowed in the program are iodized table salt and green beans, snow peas and sugar snap peas (which are the only legumes allowed). Foods that should be avoided on this program include refined sugar, artificial sugars, alcohol, processed foods, white potatoes, , grains, legumes (except those noted above), dairy (with the exception of ghee), MSG, all soy products, sulfites, carrageenan, baked goods, and “junk food.” Unlike the Paleo diet, natural sugars such as honey, maple syrup, agave, or stevia are not allowed.

The premise of this program is that by eliminating all potentially inflammatory foods, the body will be allowed to reset. After the 30-day period, one food or food group at a time is re-introduced for three days, if you still feel good, you would continue this food and re-introduce another category after three days; if then you develop a symptom, the recommendation is that the exacerbating food group be eliminated. Unfortunately, the guidelines for this diet suggest that if you go off the program and eat a food that should not be eaten in the initial 30 days, you should start over at day one. The disadvantages of this diet from a nutritional perspective are similar to the Paleolithic diet in the risk of low calcium and micronutrient intake. Furthermore, it may be very difficult to follow this program given it’s restrictive. In respect to scientific literature, there is not much at this time specific to the Whole30 program, it essentially falls in the low carbohydrate category. Research on low carbohydrate diets have shown short-term success in reducing weight and cardiovascular risk factors (Naude et al., 2014) but long-term studies are limited. While the Whole30 program does not promote weight loss, weight loss often results.   

In conclusion…

The biggest problem with “diets” or nutritional programs per se is that they are often thought of as short-term. Regardless of the intent – weight loss or improvement in health conditions – as healthcare professionals, it is best to promote healthy eating and lifestyle changes that are sustainable long-term and are achievable for our patients. Lastly, when we identify that a patient is following a particular nutritional program, it is of utmost importance to determine if the program they have chosen provides them with the necessary macro- and micronutrients our bodies require for optimal health.
 

References:
Gregor, M.F. & Hotamisligil, G.S. (2011). Inflammatory mechanisms in obesity. Annual Review of Immunology, 29(1), 415-445. doi: 10.1146/annurev-immunol-031210-101322

Johnson, J. (2019, May 9). What to know about the Whole30 diet. Medical News Today. Retrieved from https://www.medicalnewstoday.com/articles/325141.php

Manheimer, E.W., van Zuuren, E.J., Fedorowicz, Z., Pijl, H. (2015). Paleolithic nutrition for metabolic syndrome: systematic review and meta-analysis. The American Journal of Clinical Nutrition, 102(4), 922-32. doi: 10.3945/ajcn.115.113613

Naude, C. E., Schoonees, A., Senekal, M., Young, T., Garner, P., & Volmink, J. (2014). Low carbohydrate versus isoenergetic balanced diets for reducing weight and cardiovascular risk: A systematic review and meta-analysis. PLoS One, 9(7), e100652. doi: 10.1371/journal.pone.0100652

The Whole30 program. Retrieved from https://whole30.com/whole30-program-rules/

U.S. Department of Health and Human Services and U.S. Department of Agriculture, (2015). 2015–2020 Dietary Guidelines for Americans, 8^th Edition. Retrieved from http://health.gov/dietaryguidelines