A Pesco-Mediterranean Diet With Intermittent Fasting

JACC Review Topic of the Week

James H. O'Keefe, MD; Noel Torres-Acosta, MD; Evan L. O'Keefe, MD; Ibrahim M. Saeed, MD; Carl J. Lavie, MD; Sarah E. Smith, PHD; Emilio Ros, MD, PHD


J Am Coll Cardiol. 2020;76(12):1484-1493. 

In This Article

Abstract and Introduction


As opportunistic omnivores, humans are evolutionarily adapted to obtain calories and nutrients from both plant and animal food sources. Today, many people overconsume animal products, often-processed meats high in saturated fats and chemical additives. Alternatively, strict veganism can cause nutritional deficiencies and predispose to osteopenia, sarcopenia, and anemia. A logical compromise is a plant-rich diet with fish/seafood as principal sources of animal food. This paper reviews cumulative evidence regarding diet and health, incorporating data from landmark clinical trials of the Mediterranean diet and recommendations from recent authoritative guidelines, to support the hypothesis that a Pesco-Mediterranean diet is ideal for optimizing cardiovascular health. The foundation of this diet is vegetables, fruits, nuts, seeds, legumes, whole grains, and extra-virgin olive oil with fish/seafood and fermented dairy products. Beverages of choice are water, coffee, and tea. Time-restricted eating is recommended, whereby intermittent fasting is done for 12 to 16 h each day.


As Homo sapiens, we are evolutionarily adapted to obtain calories and nutrients from plant and animal sources; accordingly, humans are classified as opportunistic omnivores.[1,2] The chemistry and anatomy of our digestive tract testify to our omnivorous lineage. Indigestible fiber—found only in plants—is vital for gastrointestinal tract health; and like herbivores, we have sucrases in our gut enabling us to digest fruit. On the other hand, like carnivores, we have numerous proteases in our gut specifically designed to help digest animal protein.

Archeological and anthropological data show that pre-agricultural hunter-gatherer societies derived 14% to 50% of calories consumed from animal-based foods such as wild fish, seafood, wild birds, eggs, and game meats, which are typically low in saturated fats and rich in omega-3 fatty acids (ω-3FAs).[1,3] Still, plant-rich diets confer health benefits including reduced risk for cardiovascular disease (CVD). Vegans and vegetarians, compared with nonvegetarians, have lower body mass indexes with favorable levels of blood pressure and low-density lipoprotein cholesterol (LDL-C).[4,5] Lacto-ovo vegetarian diets (no animal-based food except eggs and dairy) generally show no adverse effects; however, veganism (no animal-based food) can result in deficiencies of important nutrients such as vitamin B12, high-quality proteins, iron, zinc, ω-3FA, vitamin D, and calcium.[4] Moreover, plant-based diets comprised of sweets, refined grains, fries, chips, and other processed foods correlate with worse CVD outcomes, whereas vegetarian diets emphasizing fresh produce, nuts, legumes, whole grains, tea, and coffee associate with improved outcomes.[6]

Dietary sources of vitamins B12 and D are almost solely animal products. Without adequate supplementation, deficiency of these nutrients can cause neurocognitive deficits, anemia, and immunodeficiency.[7] Studies suggest that prolonged strict veganism increases the risk for bone fractures and sarcopenia, and depressive symptoms increase with the number of food groups excluded.[4,8,9] Attaining optimal health while following a vegan diet requires ongoing attention to detail and a sophisticated understanding of supplementation.

In contrast, many people in modern Western cultures overconsume meat, particularly highly processed meat from animals raised in inhumane conditions, fed unnatural foods, and often treated with hormones and antibiotics.[1] This predisposes to a wide range of chronic illnesses prevalent in our society including CVD, diabetes, and cancers of the gastrointestinal tract.[4,10] Thus, although many individuals will benefit from a reduction in the consumption of meat, especially processed meat,[11] modest amounts of wholesome animal-based foods such as fish and fermented dairy products continue to play an essential role in the ideal diet.[3,4]

In this review, we propose the Pesco-Mediterranean diet as a solution to this "omnivore's dilemma" about what to eat. Scientific evidence will be presented to support the Pesco-Mediterranean diet, which is modeled on the traditional eating patterns of Mediterranean populations. It is a plant-rich diet with seafood as the predominant source of animal protein. Intermittent fasting is also recommended, because it was an inherent feature of these traditional cultures and it promotes health.