It is undeniable that the quality and composition of your diet is one of the most important parts of your daily lifestyle routine, making the most significant contribution to your expression of health or disease.  However, with the confusing excess of misleading, erroneous information on diet/nutrition that continues to be promoted, it is essential to clarify and define optimal nutrition as a dietary plan that gives you the greatest opportunity to be well, to prevent/reverse chronic degenerative disease, to sustain the healthiest weight and body fat, and promote your best performance and function at any age. Simply put, optimal nutrition should promote optimal health.

While diet and nutrition are intimately connected, they are not the same thing, and it is important to appreciate and understand the fundamental difference and relationship of these concepts. Diet refers specifically to what you decide to put into your mouth and eat on a regular basis. Nutrition, on the other hand, is not just about what you consume; it also embraces the bigger picture of digestibility and nutrient availability. It involves not only what you eat, but also all the relationships and reactions that your body has with those things.  This includes considerations of how you digest your food, how you absorb the available nutrients, how you circulate those nutrients within the bloodstream. 

It also includes how these nutrients are incorporated into the cells of the body to nurture all of the body’s tissues, organs, and systems and to promote new growth and life of the entire living ecosystem we call the human body. All of these factors come under the umbrella of nutrition, affecting the bioavailability of nutrients to promote life and health. Any aspect of your life and lifestyle choices that enhances or compromises any of these factors will influence the quality of your nutrition. For example, restorative sleep and exercise promote better digestion, circulation, and absorption that enhance the quality of nutrition. By contrast, unresolved chronic stress or sleep deficiency can compromise effective nutrition. 

For any diet or eating plan to promote overall health and reduce dangerous excesses of weight and body fat, it must satisfy some very specific needs and meet some basic requirements. All animals in nature, including humans, have evolved anatomically and physiologically in ways  that make them best suited to eat in a certain place in the food chain. While humans have eaten everything under the sun throughout our history, our evolutionary biology connected to other non-human primates (chimps, gorilla and bonobos), the anatomy of our jaws , teeth, length of our digestive tract, size of our liver, nature of our digestive enzymes, etc. strongly suggest that we are select herbivore/frugivores, fairing best on a diversity of fruits, and vegetables. These considerations must be respected in any determination of optimal nutrition, to clearly emphasize what food is in our best interest.   

Optimal nutrition is provided by a dietary plan that has the lowest calorie density, the highest nutrient density, and the elimination of risky excesses associated with animal based foods, and processed/ultra-processed foods. These important dietary requirements are only provided by a high fiber, low fat, whole-food, plant-exclusive diet without added salt, extracted, isolated plant oils, and refined sugar (SOS-free). That means a diet devoid of all meat, dairy products, and processed junk food, and loaded with raw and cooked organic, unrefined, unprocessed plant foods. 

As pointed out by nutrition scientist, Dr. Barbara Rolls, in her classic book Volumetrics, the calorie content of the cornucopia of fruits and non-starchy vegetables—the variety of leafy greens, leafy herbs, cucumbers, celery, peppers, etc.—is the lowest of all foods in the approximate range of 100-400 calories per pound. These foods have a high fiber and water content (non-caloric components accounting for a significant amount of their weight) and can be eaten freely and plentifully to support healthy weight loss and weight control, with the added benefit that their fiber and water content provide a stabilizing sense of fullness and satiety.  Starchy vegetables, such as potatoes and yams, whole grains and cereals, and legumes (including beans, peas, and lentils), are in the range of 300-780 calories per pound and also promote the calorie-density levels, nutritional values, and satiety essential for the long-term maintenance of health and low body fat. (1)

Furthermore, the American Cancer Institute and the World Cancer Research Fund have suggested that a diet containing foods with an average calorie density of approximately 600 calories or less per pound is ideal for reducing cancer risk and promoting long-term weight regulation. Therefore, fruits, vegetables, and cooked starches  should comprise 90-95% of everything you eat. The remaining part of your diet should include regular intake of nuts/seeds that are remarkably beneficial . Nuts, seeds, and avocados, provide significant essential nutrients and health benefits. However, because of their high fat and calorie density, I recommend a limited consumption of these foods, usually no more than one to two ounces of nuts or a few slices of avocado in any day, as part of an optimal nutrition and weight regulating diet. 

Another significant feature of the whole food plant-exclusive, SOS-free diet is that plant foods with the lowest calorie density also have the greatest nutrient density (nutrient availability), or the greatest nutrient to calorie ratio. So when you eat this way you are getting the best nutritional return for your calorie investment; the biggest bang for your buck.  A diet that is primarily fruits and vegetables provides the necessary/greatest amount of macronutrients (proteins, fats, carbohydrates), and micronutrients (vitamins, minerals, phytonutrients, and antioxidants), for the least number of calories. For the most part, micronutrients are found in their greatest concentrations in plant-based foods. In addition to vitamins and minerals, plant foods contain a wide variety of specific phytonutrients, antioxidants, and anti-aging factors: isothiocyanates in broccoli, cabbage and Brussels sprouts; isoflavones in soybeans; curcuminoids in turmeric; tannins in berries in pomegranates, walnuts, and almonds; fisetin in strawberries, onions and grapes; and quercetin in apples, onions, parsley, and dark berries.

This Whole plant food approach approach has been justified and emphasized by some of the most extensive epidemiological studies that have been ongoing for decades, including the Adventist 2-health study and EPIC-Oxford. (2)(3) Data from these studies strongly suggest that eating whole plant food significantly reduces risky metabolic markers, improves aberrant body functions, and  decreases chronic degenerative disease, including the significant decreases in blood pressure, LDL-cholesterol, blood sugar/Type 2 diabetes, heart disease, and cancer

However, Americans are typically eating a diet that is 60-70% processed/ultra-processed  food, more than 30% animal products, and less than 5% whole fruits and veggies. This dietary plan contains risky excesses of artificial additives, salt, fat, refined sugar, and other nutrient excesses, as well as glaring  deficiencies of key nutrients including fiber which is essential to nourish the trillions of microbes of your microbiome that promotes optimal function of your immune system, digestive system, cholesterol metabolism, hormone balance, and the brain. 

These dietary aberrations promote hyper-acidity (metabolic acidosis), chronic inflammation, and oxidative stress that are the foundation of all chronic disease. The increased  consumption of cooked animal and processed foods provide a dangerous increase in a number of chemical agents (including heterocyclic amines, saturated and trans fats, oxysterols/oxidized cholesterol, advanced glycation end-products (AGE), heme iron, N-glycolylneuraminic acid (NeuG5c), trimethylamine N-oxide (TMAO), methionine, and arachidonic acid) that contribute to chronic inflammation, systemic toxicity, damage to blood vessels in the heart and brain, oxidative stress in the mitochondria and vital organs, premature aging,  high blood pressure, increased visceral fat, heart disease and a variety of cancers. (4)(5)(6)(7)

Optimal nutrition can only be defined and provided by a whole food plant-exclusive diet without added salt, extracted oils and refined sugar, and the total exclusion of all processed/ultra-processed foods. Food should be chewed thoroughly, eaten slowly, and consumed primarily in whole-food form to respect the matrix and architecture of the cornucopia of nutrients, and the unique synergies/interactions, that only whole food can provide.  

References

1. Rolls, B. Volumetrics. William Morrow Paperbacks, 2000.

2. Orlich MJ, et al. Vegetarian dietary patterns and mortality in Adventist Health Study 2. JAMA Int Med. 2013 Jul 8;173(13):1230-1238.

3. Key TJ, et al. Plant-based diets and long-term health: findings from the EPIC-Oxford study. Proc Nutr Soc. 2022 May;81(2):190-198.

4. Yanigisawa R, et al. The impacts of cholesterol, oxysterols and cholesterol dietary compounds on the immune system. Int J Mol Sci. 2022 Oct 13;23(20):12236.

5. Mengchao J, et al. The role of intestinal microbiota in cardiovascular disease. J Cell Mol Med.  2019 Feb 3;23(4):2343-2350. 

6. Bastide NM, et al. Heme iron from meat and risk of colorectal cancer: a meta-analysisand a review of the mechanisms involved. Cancer Prev Res. (Phila) 2011 Feb;4(2): 117-84.