Q: What do you eat on a daily basis?
A: I generally eat two meals a day. I like to precede my first meal of the day with my main physical activity if possible, and I follow the physical activity with a large meal of sweet fruit, bananas being a fairly common choice. Sometimes I may get as much as 2/3rds of my daily calories from this meal. In the evening I will start dinner with either an acid or sub acid fruit of choice, depending on the season, such as fresh-squeezed orange juice or grapes, and then follow with a large salad, averaging two large heads of lettuce (most commonly romaine) a day, but this could vary depending on food availability and the season. The salad may be as simple as chopped tomatoes and squished grapes on top for a low fat salad, or it could be blended avocado/orange juice/ tomato dressing on a day where I include overt fats. Depending on one's caloric needs, it's not only possible but easy and enjoyable to get the necessary calories in these two meals.
A: Vitamin B12 is unique in that it is the only water soluble vitamin of which the body has the ability to store, and it is not necessary to replenish the vitamin via ingestion and absorption on a daily basis and possibly not even on a yearly basis. The body stores most of its B12 in the liver. According to the upper limit of the United States Government's Recommended Daily Allowance (which for Vit. B12 is 2-4µg/day)1 for B12 and the body’s lower limit on B12 storage ability, one could store enough vitamin B12 for nearly two years and that’s under the assumption that absolutely no B12 was consumed and absorbed during that time. However, this timetable is overly conservative. Slightly less than the minimum RDA amount for B12 is secreted in bile into the small intestine from the liver on a daily basis and this B12 is reabsorbed in the small intestine and returned to the liver in the cycle known as “enterohepatic circulation.” Of the stored vitamin, 99.9% of it is reused on a daily basis.2 Thus, it may be possible for an individual with initial adequate B12 stores to go for years or even decades without the consumption of B12 and not exhibit any deficiency of the micronutrient while maintaining optimal health. However, those consuming a plant based diet of which organic plants have been fertilized with manure are likely to consume B12 as the B12-producing bacteria in other animals end up in their feces and then in the plant soil (one of the most common methods of ingesting B12 is through "contamination").3 Thus, sometimes not over-obsessing about cleaning all the dirt off your organically-grown lettuce before you eat it might be a healthy practice. It is also a well known fact that most of the B12 deficiencies witnessed in developed countries are not the result of inadequate intake of the nutrient but rather problems of absorption.4
The quick answer - enjoy your food.
Q: Is fruit too high in sugar and too low in fiber?
A: The claim is often made that there's too much sugar in domesticated fruits compared to most wild fruits. However, humans are known to require a “high quality” diet (higher quality foods are foods that have more available energy and less indigestible material), even higher quality than a chimpanzee. A comparison of the human and chimpanzee guts demonstrates that, on average, about 2/3rds of the human gut is comprised of the small intestine, while the large intestine makes up only 1/5th of the total GI tract. In comparison, the chimpanzee exhibits almost the complete opposite (its small intestine comprises 1/4th of its gut and its large intestine comprises about half of it).5,6 The primary role of the small intestine is nutrient absorption and it’s estimated that the human intestine has the ability to absorb up to 5,400 grams of glucose and 4,800 grams of fructose per day7 (eating 3000 Calories/day the low-fat raw vegan may consume around 730g of carbohydrates, not including water, and of that about 370g of sugar). In contrast, the large intestine is responsible for packing fiber into feces, and the size of the large intestine sets the upper limit on the amount of fiber an organism can handle.
What the data demonstrates is that, compared with chimpanzees, human require a greater ratio of digestible to indigestible material in their food, and given that the biology of both humans and chimpanzees is designed in a such away that the energy generating processes in both animals is fueled by sugars, the natural answer would be that humans need a greater proportion of sugar to fiber in their diet than do chimpanzees. Thus, it may be argued that domesticated fruits are best suited for humans while many of the fibrous wild fruits are best left to the other apes.
Acknowledging the above claims, It’s not uncommon for an individual following a low fat raw vegan program to consume two to three times the United States government-established Adequate Intake for fiber in a given day on a diet exclusively comprised of domesticated fruits and vegetables.
Q: What is the "Anomaly Species Hypothesis"?
A: The Anomaly Species Hypothesis was formulated from what appeared to be a clash between the nutrition and biological sciences with human evolutionary theory. Said differently, the hypothesis revolves around a discord between Homo sapiens sapiens' metabolic and anatomical adaptations. Our metabolic adaptations have us rooted in consuming sugar to produce the necessary energy in the body, as evidenced by the processes carried out in the cell cytoplasm (glycolysis) and Mitochondria (oxidative phosphorylation).
However, when [what became] the human and chimpanzee lineages split, over time the [pre]-humans took advantage of the changing (drier) climate and began to move into the ever expanding savannas, while the [pre]-chimpanzees remained in the forests. As a result, the populations in the chimp lineage began to decline while the human lineage populations began to increase. Savanna life warranted a different diet and this began with late Australopithecine species variations consuming raw, rough, plant material, including raw roots.
This continued until Homo erectus, where it is believed that cooking made a larger expanse of roots available for consumption, year round, eliminating a period of scarcity and turning what used to be fallback food (roots/tubers/corms/rhizomes) into a "higher quality" food by cooking it. As a result of this stable source of calories, the soon to be humans (still about 2 million years shy of today) were able to grow expensive organs such as increased brain size, but at the expense of other organs (the human's entire GI tract is much smaller than the chimpanzee's and its proportions have changed to allow for greater nutrient absorption and less handling of indigestible material).
While our anatomy (not only the GI tract, but also including tooth and jaw structure) changed fairly drastically over the past 2 million years (anatomy can evolve in a population fairly rapidly), our metabolic needs remained the same. In an analogy, our car still required gasoline but the engine was different. We still required carbohydrates (sugars) for fuel but our gastrointestinal tract had changed form. This leaves us with two options - consuming what might be considered suboptimal food (cooked roots) to meet our sugar needs and conform to our anatomical restrictions, or consuming metabolically rooted food in an altered form (fruits with greater sugar content and less fiber).
Q: What is the "Anomaly Species Hypothesis"?
A: The Anomaly Species Hypothesis was formulated from what appeared to be a clash between the nutrition and biological sciences with human evolutionary theory. Said differently, the hypothesis revolves around a discord between Homo sapiens sapiens' metabolic and anatomical adaptations. Our metabolic adaptations have us rooted in consuming sugar to produce the necessary energy in the body, as evidenced by the processes carried out in the cell cytoplasm (glycolysis) and Mitochondria (oxidative phosphorylation).
However, when [what became] the human and chimpanzee lineages split, over time the [pre]-humans took advantage of the changing (drier) climate and began to move into the ever expanding savannas, while the [pre]-chimpanzees remained in the forests. As a result, the populations in the chimp lineage began to decline while the human lineage populations began to increase. Savanna life warranted a different diet and this began with late Australopithecine species variations consuming raw, rough, plant material, including raw roots.
This continued until Homo erectus, where it is believed that cooking made a larger expanse of roots available for consumption, year round, eliminating a period of scarcity and turning what used to be fallback food (roots/tubers/corms/rhizomes) into a "higher quality" food by cooking it. As a result of this stable source of calories, the soon to be humans (still about 2 million years shy of today) were able to grow expensive organs such as increased brain size, but at the expense of other organs (the human's entire GI tract is much smaller than the chimpanzee's and its proportions have changed to allow for greater nutrient absorption and less handling of indigestible material).
While our anatomy (not only the GI tract, but also including tooth and jaw structure) changed fairly drastically over the past 2 million years (anatomy can evolve in a population fairly rapidly), our metabolic needs remained the same. In an analogy, our car still required gasoline but the engine was different. We still required carbohydrates (sugars) for fuel but our gastrointestinal tract had changed form. This leaves us with two options - consuming what might be considered suboptimal food (cooked roots) to meet our sugar needs and conform to our anatomical restrictions, or consuming metabolically rooted food in an altered form (fruits with greater sugar content and less fiber).
Q: I live in a temperate climate, and I'm a bit concerned about my Vitamin D status during the winter. What should I do?
A: Vitamin D is the only vitamin that functions as a hormone in our body, and humans can obtain it in three different ways. It can be obtained in an inactive form from consuming animal foods (D3; this source of D3 is not recommended) and plants (D2), although there has been a lack of research as to the amount of Vitamin D in plants. The most well known way that Vitamin D can be obtained is through our synthesis of it, where a Vitamin D precursor is secreted by glands located in skin cells throughout all layers of the skin (It's often been said that a significant amount of the Vitamin D can be lost from washing your skin directly after sun exposure, but given the distribution of Vitamin D throughout the different layers of skin and given that some remains embedded in the cell membranes upon exposure to sunlight, it should not be of concern.) Ultra Violet B light is responsible for converting this Vitamin D precursor to the same inactive form that is obtained from animal foods. These inactive forms are activated by two reactions that occur in the liver and the kidneys. In temperate climates, the United States government's recommended intake for Vitamin D has been cited as being obtainable by daily exposure to sun for between 5 and 15 minutes during late morning and afternoon (or great equivalent periods less frequently). However, significantly less synthesis is possible during the winter.
Luckily, because Vitamin D is a fat-soluble vitamin, our bodies have the ability to store it. The blood is the largest storage site of Vitamin D, but the vitamin can only be stored in the blood for up to three weeks. However, Vitamin D may also be stored in the skin, muscle, and fatty tissue for longer, undefined periods of time. As a result, it's possible that one could safely go at least a month without Vitamin D consumption or synthesis and not experience any deficiencies or decline in health (this period may be even longer). Also, due to the lack of research on the amount of Vitamin D2 in plant foods, the degree of adequacy in the combination between plant food consumption and Vitamin D stores is unknown, and it could be greater than our current understanding proves it to be. In any case, one short vacation to a warm, sunny location during mid winter for a week would provide a further guarantee to carry adequate stores throughout the second half of the winter.
Vitamin D, as all vitamins are, is considered an "essential nutrient", the definition of which "is a nutrient required for normal body functioning that either cannot be synthesized by the body at all, or cannot be synthesized in amounts adequate for good health, and thus must be obtained from a dietary source." This leads to the question, can sunlight provide adequate amounts of Vitamin D, and if not, given the human-lineage's evolutionary record of consuming a plant-based diet, what does this mean for the Vitamin D content in plant foods? It's possible that there could be more Vitamin D in plant foods than we currently understand there to be, but it's also possible that Vitamin D could be inappropriately deemed a vitamin. The jury is still out.
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1. Food and Nutrition Board. 1998. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline. Washington, DC: National Academy Press. p.306-356.
2. Heyssel RM, Bozian RC, Darby WJ, Bell MC. 1966. Vitamin B12 Turnover in Man: The Assimulation of Vitamin B12 from Natural Foodstuff by Man and Estimates of Minimal Daily Dietary Requirements. Am J Clin Nutr 18:176-184.
3. Mozafar A. 1994. Enrichment of some B-vitamins in plants with application of organic fertilizers. Plant Soil 167:305-311.
4. Gropper SS, Smith JL, Groff JL. 2009. Advanced Nutrition And Human Metabolism, Fifth Edition. Belmont: Wadsworth. p.362.
5. Milton K. 1987. Primate diets and gut morphology: implications for hominid evolution. In: Food and Evolution: Toward a Theory of Human Diets, edited by M. Harris and E. B. Ross. Philadelphia, PA: Temple Univ. Press. p.93-108.
6. Milton K. 1986. Digestive physiology in primates. Am Physiol Soc 1:76-79.
7. Gropper SS, Smith JL, Groff JL. 2009. Advanced Nutrition And Human Metabolism, Fifth Edition. Belmont: Wadsworth. p.71.
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1. Food and Nutrition Board. 1998. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline. Washington, DC: National Academy Press. p.306-356.
2. Heyssel RM, Bozian RC, Darby WJ, Bell MC. 1966. Vitamin B12 Turnover in Man: The Assimulation of Vitamin B12 from Natural Foodstuff by Man and Estimates of Minimal Daily Dietary Requirements. Am J Clin Nutr 18:176-184.
3. Mozafar A. 1994. Enrichment of some B-vitamins in plants with application of organic fertilizers. Plant Soil 167:305-311.
4. Gropper SS, Smith JL, Groff JL. 2009. Advanced Nutrition And Human Metabolism, Fifth Edition. Belmont: Wadsworth. p.362.
5. Milton K. 1987. Primate diets and gut morphology: implications for hominid evolution. In: Food and Evolution: Toward a Theory of Human Diets, edited by M. Harris and E. B. Ross. Philadelphia, PA: Temple Univ. Press. p.93-108.
6. Milton K. 1986. Digestive physiology in primates. Am Physiol Soc 1:76-79.
7. Gropper SS, Smith JL, Groff JL. 2009. Advanced Nutrition And Human Metabolism, Fifth Edition. Belmont: Wadsworth. p.71.
