by Jack Norris, Registered Dietitian
Contents
- EPIC-Oxford (2016)
- EPIC-Oxford (2003)
- Adventist Health Study-2 (2013)
- Appendix A: NSP and AOAC Fiber
- Bibliography
EPIC-Oxford (2016)
EPIC-Oxford is a cohort study of “generally health-conscious” British residents, and it follows large numbers of vegetarians (Sobiecki, 2016). This assessment was conducted in 2010.
- The nutrient intakes are based on food frequency questionnaires (FFQ). FFQs are more useful for judging relative nutrient intakes between groups than for measuring absolute amounts of nutrients for comparison to dietary recommendations.
- FFQ don’t include all the foods vegans typically eat, and in the case of EPIC-Oxford, it’s likely they don’t accurately reflect typical portion sizes either. This could explain why a much higher percentage of vegans reported implausibly low calorie intakes (43% of vegan men and 33% of vegan women, compared with 33% of meat-eating men and 19% of meat-eating women).
- Nutrients amounts are estimated from nutrient database tables rather than directly measuring the nutrient content of the food. Direct measurements are very expensive.
- Nutrients from fortified foods—such as vitamin B12 fortified foods—are rarely accounted for, nor are supplements.
Given all these potential problems, the studies should mainly be used to spot glaring problems or trends.
The table below notes the most interesting findings from this current report.
| Men | Women | |||||
|---|---|---|---|---|---|---|
| Meat | LOV | Vegan | Meat | LOV | Vegan | |
| Number | 3,798 | 1,516 | 269 | 14,446 | 5,157 | 534 |
| Calories | 2,251 | 2,183 | 2,123 | 2,040 | 1,932 | 1,871 |
| Fat (%) | 31 | 30 | 30 | 31 | 30 | 31 |
| Saturated Fat (%) | 10 | 10 | 7 | 10 | 9 | 7 |
| Carbohydrate (%) | 48 | 52 | 54 | 48 | 53 | 54 |
| Protein (%) | 17 | 14 | 13 | 17 | 14 | 13 |
| Protein (g/kg) | 1.1 | 1.0 | 0.9 | 1.3 | 1.1 | 1.0 |
| Calcium (mg) | 1,120 | 1,153 | 862 | 1,078 | 1,099 | 839 |
| Zinc (mg) | 11 | 11 | 9 | 10 | 10 | 8 |
| Iron (mg) | 17 | 18 | 20 | 16 | 16 | 18 |
| Men & Women | ||||||
| Vitamin A (RAE) | 1,042 | 701 | 623 | |||
Calcium intakes for vegans were significantly higher than the previous EPIC-Oxford report from 2003 (see below).
Vitamin A and zinc are a little low based on these data. The DRI for vitamin A is 900 RAE for men and 700 RAE for women. The RDA for zinc is 11 mg for men and 8 mg for women. I also prefer to see vegan protein intakes higher than the .9 g/kg of body weight (for men). But given that the overall food intake reported for vegans was low, intakes of these nutrients were probably a bit higher than reported. Still, these are nutrients I consider to be important for vegans, and if you don’t know much about them, please check out the VeganHealth.org articles, Vitamin A and Zinc.
The EPIC-Oxford report includes information on supplement intake, indicating that 50% of vegans were supplementing with vitamin B12.
EPIC-Oxford (2003)
Table 2 below shows the nutrient intakes of participants in EPIC-Oxford (Davey, 2003). Notes on this data:
- Did not include supplements, but did include fortified foods.
- Vitamin A is listed as measured in micrograms of retinol, rather than retinol activity equivalents (RAE). Plant foods do not contain retinol, yet vegans are listed as having an intake of retinol. But that intake seems very low compared to what would be expected if carotenoids were included. So, it is unclear how the vitamin A amount was determined.
Adventist Health Study-2 (2013)
Table 2 below also shows nutrient intakes from Adventist Health Study-2 (AHS-2) (Rizzo, 2013). Notes on this data:
- Data includes fortified foods and supplements. No separate analysis was provided without supplements.
These nutrient intakes were based on food frequency questionnaires (FFQs), the least accurate way to measure nutrient intakes. FFQs ask how often someone eats a long list of foods. Two better ways to measure nutrient intakes are to ask participants to keep a food diary, or to analyze duplicate portions in a laboratory. EPIC-Oxford plans to report nutrient intakes using food diaries in a sample of the population. The authors reported that:
Seven-day food diaries were completed by 31,000 participants, and these will provide further information on energy intake. Preliminary analysis of a sample of 150 food diaries indicates that the FFQ does underestimate energy intake, and therefore most nutrient intakes, among vegans (unpublished data).
| EPICA | AHS-2B | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Men | Women | Men & Women | |||||||||||
| Non-Veg | Pesco | Lacto-Ovo | Vegan | Non-Veg | Pesco | Lacto-Ovo | Vegan | Non-Veg | Semi | Pesco | Lacto-Ovo | Vegan | |
| Number | 6,951 | 1,500 | 3,748 | 770 | 22,962 | 6,931 | 12,347 | 13,432 | 33,634 | 4,042 | 6,583 | 21,799 | 5,694 |
| Calories | 2,186 | 2,119 | 2,090 | 1,907 | 1,910 | 1,845 | 1,810 | 1,660 | 1,773 | 1,609 | 1,815 | 1,803 | 1,791 |
| Carb (g) | 256 | 264 | 268 | 262 | 231 | 236 | 239 | 233 | 267 | 281 | 285 | 285 | 309 |
| Carb % | 47 | 50 | 51 | 55 | 48 | 51 | 53 | 56 | 53 | 56 | 57 | 57 | 62 |
| Protein (g) | 87 | 74 | 68 | 62 | 83 | 69 | 62 | 56 | 75 | 71 | 73 | 71 | 71 |
| Protein % | 16 | 14 | 13 | 13 | 17 | 15 | 14 | 14 | 15 | 14 | 15 | 12 | 14 |
| Fat (g) | 78 | 74 | 73 | 60 | 68 | 64 | 62 | 52 | 77 | 74 | 72 | 73 | 65 |
| Fat % | 32 | 31 | 31 | 28 | 32 | 31 | 30 | 28 | 35 | 33 | 33 | 33 | 29 |
| Sat Fat (g) | 26 | 22 | 22 | 11 | 22 | 19 | 19 | 10 | 19 | 17 | 15 | 16 | 11 |
| Sat Fat % | 11 | 9 | 9 | 5 | 10 | 9 | 9 | 5 | 9 | 8 | 7 | 7 | 5 |
| Fiber (g) | 19 | 22 | 23 | 28 | 19 | 22 | 22 | 26 | 30 | 35 | 37 | 37 | 46 |
| n3 (g) | – | – | – | – | – | – | – | – | 2.1 | 2.0 | 2.2 | 2.0 | 1.8 |
| Vit A – retinol (mcg) | 740 | 337 | 306 | 74 | 654 | 308 | 277 | 77 | – | – | – | – | – |
| beta-carotene (mcg) | – | – | – | – | – | – | – | – | 5,525 | 5,861 | 7,417 | 6,303 | 8,474 |
| Vit B1 – thiamin (mg) | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | – | – | – | – | – |
| Vit B2 – riboflavin (mg) | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | – | – | – | – | – |
| Vit B3 – niacin (mg) | 25 | 22 | 21 | 24 | 23 | 20 | 18 | 21 | – | – | – | – | – |
| Vit B6 (mg) | 2.3 | 2.1 | 2.0 | 2.2 | 2.2 | 2.0 | 1.9 | 2.1 | 3.1 | 3.4 | 3.5 | 3.3 | 3.2 |
| Vit B12 (mcg) | 7.3 | 5.0 | 2.6 | 0.4 | 7.0 | 4.9 | 2.5 | 0.5 | 7.1 | 8.3 | 8.5 | 8.0 | 6.3 |
| Folate (mcg) | 329 | 358 | 367 | 431 | 321 | 346 | 350 | 412 | 672 | 731 | 766 | 729 | 723 |
| Vit C (mg) | 119 | 130 | 123 | 155 | 138 | 147 | 147 | 169 | 250 | 273 | 308 | 271 | 293 |
| Vit D (mcg) | 3.4 | 2.9 | 1.6 | 0.9 | 3.3 | 2.8 | 1.5 | 0.9 | 6.1 | 5.5 | 5.8 | 4.6 | 2.4 |
| Vit E (mg) | 11.8 | 13.0 | 13.7 | 16.1 | 10.7 | 11.4 | 11.6 | 14.0 | 20.0 | 26.1 | 26.9 | 24.7 | 18.5 |
| Calcium (mg) | 1,057 | 1,081 | 1,087 | 610 | 989 | 1,021 | 1,012 | 582 | 1,072 | 1,195 | 1,125 | 1,145 | 933 |
| Iron (mg) | 13.4 | 14.0 | 13.9 | 15.3 | 12.6 | 12.8 | 12.6 | 14.1 | 20.0 | 21.7 | 22.4 | 22.1 | 22.2 |
| Magnesium (mg) | 366 | 396 | 396 | 440 | 341 | 358 | 352 | 391 | 448 | 492 | 519 | 514 | 591 |
| Phosphorus (mg) | – | – | – | – | – | – | – | – | 1,359 | 1,360 | 1,366 | 1,348 | 1,370 |
| Potassium (mg) | 3,965 | 3,940 | 4,029 | 3,937 | 3,839 | 3,759 | 3,956 | 3,817 | 3,487 | 3,627 | 3,853 | 3,667 | 4,120 |
| Sodium (mg) | – | – | – | – | – | – | – | – | 3,272 | 3,346 | 3,101 | 3,432 | 3,066 |
| Zinc (mg) | 9.8 | 8.6 | 8.4 | 7.9 | 9.2 | 7.9 | 7.7 | 7.2 | 11.9 | 11.6 | 11.5 | 11.5 | 11.3 |
| Numbers listed are the average for EPIC-Oxford and the median for AHS-2. A. Davey, 2003 B. Rizzo, 2013 |
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Appendix A: NSP and AOAC Fiber
EPIC-Oxford measured fiber as non-starch polysaccharides (NSP) and found vegan intake to average 28.9 g/day (Sobiecki, 2016). In contrast, the Adventist Health Study-2 found vegan intake to average 46.7 g/day (Rizzo, 2013). The Adventist Health Study-2 used the Nutrition Data System for Research (NDSR) 2008 database for measuring fiber in foods, which, as of 2020, listed total dietary fiber as including unavailable carbohydrates (cellulose, hemicellulose, pectins, gums, and mucilages) and lignin (NDSR, 2020).
The NDSR defines fiber similarly to the Association of Official Analytical Chemists (AOAC), the definition normally used in the United States, and includes cellulose, hemicellulose, lignin, gums, modified cellulose, mucilages, oligosaccharides, pectins, and associated minor substances such as waxes, cutin, and suberin (DeVries, 1999).
The Institute of Food Science & Technology (2007) compared the fiber content of 8 foods using both the NSP and the AOAC methods; the AOAC method measured 26% more fiber than the NSP method. The UK Women’s Cohort Study compared the fiber content of different diets using both the NSP and the AOAC methods; the AOAC method measured 53% higher than the NSP method (Threapleton, 2013). Using the AOAC method in EPIC-Oxford would, therefore, show average vegan fiber intake to be closer to 36.4 to 44.3 g/day.
See the Fiber spreadsheet in the Vegan Fracture Studies for the calculations.
Bibliography
Davey GK, Spencer EA, Appleby PN, Allen NE, Knox KH, Key TJ. EPIC-Oxford: lifestyle characteristics and nutrient intakes in a cohort of 33 883 meat-eaters and 31 546 non meat-eaters in the UK. Public Health Nutr. 2003 May;6(3):259-69.
DeVries JW, Prosky L, Li B, Cho S. A historical perspective on defining dietary fiber. Cereal Foods World. 1999 May;44(5):367-369. (PDF)
Institute of Food Science & Technology (IFST). Dietary Fibre. Information Statement. April, 2007. (PDF)
NDSR Nutrients, Nutrient Ratios, and Other Food Components. Nutrition Coordinating Center. University of Minnesota. 2020 version. Accessed January 30, 2021.
Rizzo NS, Jaceldo-Siegl K, Sabate J, Fraser GE. Nutrient profiles of vegetarian and nonvegetarian dietary patterns. J Acad Nutr Diet. 2013 Dec;113(12):1610-9.
Sobiecki JG, Appleby PN, Bradbury KE, Key TJ. High compliance with dietary recommendations in a cohort of meat eaters, fish eaters, vegetarians, and vegans: results from the European Prospective Investigation into Cancer and Nutrition-Oxford study. Nutr Res. 2016 May;36(5):464-77.
Threapleton DE, Greenwood DC, Burley VJ, Aldwairji M, Cade JE. Dietary fibre and cardiovascular disease mortality in the UK Women’s Cohort Study. Eur J Epidemiol. 2013 Apr;28(4):335-46.