BMI: Body Mass Index

     A totally arbitrary, pseudo-unit, called the BMI: Body Mass Index, apparently in use from at least the mid-1970's, has been developed in an attempt to quantify obesity.  It is an arbitrary measure of dubious validity calculated by dividing your weight by the square of your height and multiplying by a fudge factor to account for English vs. metric inputs.

     So, in the metric system, BMI = weight/(height)², with weight in kilograms and height in meters.  In the English system, the units of BMI are pounds per square foot, yet this is not a measure of pressure, as pounds per square foot would be in real science.

     Worse, other "authorities" use "arm span" instead of height for the linear distance, thus further confusing this meaningless calculation.

     There is an interesting BMI calculator that not only gives the BMI, but also compares it to the generally obese public, and reports percentile rank compared to others your own age.  E.g. at 5'9" and 125 pounds, my BMI is 18.5, and compared to others of my age (63 in 2003), my weight is in the <2 percentile (meaning that >98% of the people my height are heavier/fatter than I), yet there is some palpable fat around my waist.  In the vernacular, my frame/body structure would be called "wiry".

     Remember, these BMI values are calculated in reference to the grossly obese, sick, meat-eating public, so vegetarians/vegans would generally be in the more healthful lower percentiles.  Raw-fooders, the healthiest of all, would be ranked even lower than cooked vegetarians/vegans.

     And now for some research that proves the obvious: meat-eaters are fatter than vegetarians/vegans, something all the obese meatarians on all the diet newsgroups simply do not want to hear, as evidenced to their hostility to such information.

     Definitions of various weight classifications by the World Health Organization are:

     From the same reference:

     "In the most recently published United States data (1999 to 2000), which use the WHO criteria for overweight (BMI >/= 25 kg/m2) and obesity (>/= 30 kg/m2), 67% of men and 62% of women are overweight, and 27.5% of men and 34% of women are obese.  [Note: these figures are misleading, perhaps intentionally so, because the obese are counted twice: as obese and again as overweight.  Worse, these "definitions" are quite different than the ones listed in the "definition" table above, since in the table overweight is defined as 25 - 29.9, i.e. having an upper cutoff, while the contradictory definition BMI >/= 25 has no upper cutoff, so would include the obese, as well.  Thus, with various mathematically-conflicting "definitions" used for overweight and obese, there is no way to comprehend what is being stated. - ljf]

     Apparently playing into the current hysteria over genetic research, this article states: "Studies of populations, families, adoptions, and twins have established a strong genetic role in determining body weight.", totally ignoring the facts that populations, families, and twins tend to eat exactly the same cultural diets, and that cultural diets are the fundamental cause for overweight and obesity.  When individuals are intelligent and concerned enough with their own health and abandon animal-based cultural diets for plant-based diets, they lose excess bodyweight with no effort, thus negating any claims as genetics being the fundamental cause for excess bodyweight.  Strangely, the author states: "Dietary treatment of obesity has long been controversial."; perhaps the loss of income of the medical system by intelligent dietary reform would cause such controversy?

     Taking the medical industry's position as: "Caloric restriction and macronutrient changes have resulted in frustration for patients and health care providers alike and have supported a billion-dollar market in diet schemes." apparently ignores the substantial body of medical literature that supports plant-based diets as a simple technique to lose excess weight.

     Unfortunately, this article repeats the common myth: "Increasing energy expenditure through exercise has been a mainstay of obesity therapy. ", but I find this to be highly questionable.  I personally watched a housemate drop 150 pounds, half his starting weight, in a year and a half by dietary change alone, fruits and vegetables, with no exercise routine.

     The article concludes in ignorance: "Optimal therapy for obesity, however, remains elusive."

  OBJECTIVE:: Evaluation of dietary intakes and lifestyle factors of German vegans.
  DESIGN:: Cross-sectional study.
  SETTINGS:: Germany.
  SUBJECTS:: Subjects were recruited through journal advertisements. Of 868 volunteers, only 154 participated in all study segments (pre- and main questionnaire, two 9-day food frequency questionnaires, blood sampling) and fulfilled the following study criteria: vegan dietary intake at least 1 year prior to study start, minimum age of 18 y, no pregnancy or childbirth during the last 12 months.
  INTERVENTIONS:: No interventions.
  RESULTS:: All the 154 subjects had a comparatively low BMI (median 21.2 kg/m(2)), with an extremely low mean consumption of alcohol (0.77+/-3.14 g/day) and tobacco (96.8% were nonsmokers). Mean energy intake (total collective: 8.23+/-2.77 MJ) was higher in strict vegans than in moderate ones. Mean carbohydrate, fat, and protein intakes in proportion to energy (total collective: 57.1:29.7:11.6%) agreed with current recommendations. Recommended intakes for vitamins and minerals were attained through diet, except for calcium (median intake: 81.1% of recommendation), iodine (median: 40.6%), and cobalamin (median: 8.8%). For the male subgroup, the intake of a small amount of food of animal origin improved vitamin and mineral nutrient densities (except for zinc), whereas this was not the case for the female subgroup (except for calcium).
  CONCLUSION:: In order to reach favourable vitamin and mineral intakes, vegans should consider taking supplements containing riboflavin, cobalamin, calcium, and iodine. Intake of total energy and protein should also be improved.
  SPONSORSHIP:: EDEN Foundation, Bad Soden, Germany; Stoll VITA Foundation, Waldshut-Tiengen, GermanyEuropean Journal of Clinical Nutrition (2003) 57, 947-955. doi:10.1038/sj.ejcn.1601629

PMID: 12879089

  OBJECTIVE: To compare body mass index (BMI) in four diet groups (meat-eaters, fish-eaters, vegetarians and vegans) in the Oxford cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC-Oxford) and to investigate lifestyle and dietary factors associated with any observed differences.
  DESIGN: Cross-sectional analysis of self-reported dietary, anthropometric and lifestyle data.
  PARTICIPANTS: A total of 37875 healthy men and women aged 20-97 y participating in EPIC-Oxford.
  RESULTS: Age-adjusted mean BMI was significantly different between the four diet groups, being highest in the meat-eaters (24.41 kg/m(2) in men, 23.52 kg/m(2) in women) and lowest in the vegans (22.49 kg/m(2) in men, 21.98 kg/m(2) in women). Fish-eaters and vegetarians had similar, intermediate mean BMI. Differences in lifestyle factors including smoking, physical activity and education level accounted for less than 5% of the difference in mean age-adjusted BMI between meat-eaters and vegans, whereas differences in macronutrient intake accounted for about half of the difference. High protein (as percent energy) and low fibre intakes were the dietary factors most strongly and consistently associated with increasing BMI both between and within the diet groups.
  CONCLUSIONS: Fish-eaters, vegetarians and especially vegans had lower BMI than meat-eaters. Differences in macronutrient intakes accounted for about half the difference in mean BMI between vegans and meat-eaters. High protein and low fibre intakes were the factors most strongly associated with increasing BMI.

PMID: 12833118

  OBJECTIVE: To examine the association between a range of health and nutrition indicators and popular diets.
  DESIGN: The Continuing Survey of Food Intake by Individuals (CSFII) 1994-1996 data were used to examine the relationship between prototype popular diets and diet quality as measured by the healthy eating index (HEI), consumption patterns, and body mass index (BMI). The prototype diets included vegetarian (no meat, poultry, or fish on day of survey) and non-vegetarian. The nonvegetarian group was further subdivided into low carbohydrate (less than 30% of energy from carbohydrate), medium (30% to 55%), and high (greater than 55% of energy). Within the high carbohydrate group, participants were classified as having Pyramid or non-Pyramid eating patterns. The Pyramid group was defined as 30% or less of energy from fat and at least one serving from the five major food groups in the USDA Food Guide Pyramid. Finally, the non-Pyramid group was further subdivided into low fat (less than 15% of energy from fat) and moderate fat (15% to 30% of energy from fat). In addition, a review of the published scientific literature was conducted; all studies identified were included in the review.
  SUBJECTS: 10,014 adults, aged 19 years and older, from the 1994-1996 CSFII were included in the analyses of extant data. More than 200 individual studies were included in the review of the literature.
  RESULTS: Analyses of the CSFII indicate that diet quality as measured by HEI was highest for the high carbohydrate Pyramid group (82.9) and lowest for the low carbohydrate group (44.6). Energy intakes were low for the vegetarians (1,606 kcals) and high carbohydrate/low fat group (1360 kcals). BMIs were lowest for women in the vegetarian group (24.6) and the high carbohydrate/low fat group (24.4); for men, the lowest BMIs were observed for vegetarians (25.2) and the high carbohydrate Pyramid group (25.2). Review of the literature suggests that weight loss is independent of diet composition. Energy restriction is the key variable associated with weight reduction in the short term.
  CONCLUSIONS: Diets that are high in carbohydrate and low to moderate in fat tend to be lower in energy. The lowest energy intakes were observed for those on a vegetarian diet. The diet quality as measured by HEI was highest for the high carbohydrate groups and lowest for the low carbohydrate groups. The BMIs were significantly lower for men and women on the high carbohydrate diet; the highest BMIs were noted for those on a low carbohydrate diet.

PMID: 11320946

  The effect of a strict, low-salt, uncooked vegan diet rich in lactobacteria on symptoms in 18 fibromyalgia patients during and after a 3-month intervention period in an open, non-randomized controlled study was evaluated. As control 15 patients continued their omnivorous diet. The groups did not differ significantly from each other in the beginning of the study in any other parameters except in pain and urine sodium. The results revealed significant improvements in Visual analogue scale of pain (VAS) (p=0.005), joint stiffness (p=0.001), quality of sleep (p=0.0001), Health assessment questionnaire (HAQ) (p=0.031), General health questionnaire (GHQ) (p=0.021), and a rheumatologist's own questionnaire (p=0.038). The majority of patients were overweight to some extent at the beginning of the study and shifting to a vegan food caused a significant reduction in body mass index (BMI) (p=0.0001). Total serum cholesterol showed a statistically significant lowering (p=0.003). Urine sodium dropped to 1/3 of the beginning values (p=0.0001) indicating good diet compliance. It can be concluded that vegan diet had beneficial effects on fibromyalgia symptoms at least in the short run.

PMID: 11093597

  The vegetarians in Taiwan consume diets high in polyunsaturated fatty acids. To investigate whether this dietary pattern results in high susceptibility of LDL to oxidation, 109 long-term (8 +/- 5 y) male and female vegans and lactovegetarians (ages 31-45 y) from Taipei and females from Hualien and matched omnivores were recruited to have 24-h-recall dietary assessments and blood lipid analysis. Body mass index and blood pressure were significantly lower in all vegetarian groups than in the matched omnivore groups (P < 0.05). Vegetarians consumed less energy except in the males and less protein, fat and cholesterol (P < 0.05). The mean polyunsaturated/saturated fatty acid (P/S) ratio of 2.4 in vegetarian diet was about two times that in omnivore diet (P < 0. 001). The concentrations of plasma total- and LDL-cholesterol (LDL-C) but not HDL-cholesterol (HDL-C) were significantly lower (P < 0.001) and resulting HDL-C/LDL-C ratio was 38, 46 and 30% higher (P < 0.01) in Taipei female, male and Hualien female vegetarians, respectively, than in the matched omnivores. Plasma triglyceride concentration was significantly lower only in the Hualien women vegetarians (31%, P < 0.001) than in the matched omnivores. The lag time of conjugated diene formation in LDL oxidized in vitro induced by copper was longer in Taipei female (62%, P < 0.001), male (29%, P < 0.05) and Hualien female (38%, P < 0.01), and the production of thiobarbituric acid reactive substances (TBARS) in LDL after 2-4 h of oxidation was 22-32% less (P < 0.005) in Taipei male and Hualien female vegetarians than the matched omnivores. Lag time of LDL oxidation was negatively related to LDL arachidonic (r = -0.55, P = 0.0003) and eicosapentaenoic (r = -0.47, P = 0.003) acid contents. LDL-TBARS production was negatively related to LDL linoleic acid content (r = -0.36, P = 0.023), but positively related to LDL arachidonic (r = 0.56, P = 0.0002) and eicosapentaenoic (r = 0.45, P = 0.004) acids. No significant differences were found in dietary vitamins C and E intakes and plasma LDL alpha-tocopherol concentrations between vegetarians and omnivores. Our results suggest that vegetarian diets decrease the susceptibility of LDL to oxidation despite their higher dietary P/S ratio.

PMID: 10827215

  Dietary and nutritional status of individuals habitually consuming a vegan diet was evaluated by biochemical, hematologic, and immunologic measures in comparison with a nonvegetarian group. On the basis of 4-d dietary records, the intake of female and male vegans tended to be lower in fat, saturated fat, monounsaturated fat, and cholesterol and higher in dietary fiber than that of vegetarians. With computed food and supplement intakes, vegan diets provided significantly higher amounts of ascorbate, folate, magnesium, copper, and manganese in both female and male participants. The body mass index (BMI; in kg/m(2)) of the vegans was significantly lower than that of the nonvegetarians and 9 of the 25 vegans had a BMI <19. Serum ferritin concentrations were significantly lower in vegan men but iron and zinc status did not differ between the sexes. Mean serum vitamin B-12 and methylmalonic acid concentrations did not differ; however, 10 of the 25 vegans showed a vitamin B-12 deficit manifested by macrocytosis, circulating vitamin B-12 concentrations <150 pmol/L, or serum methylmalonic acid >376 nmol/L. Vegans had significantly lower leukocyte, lymphocyte, and platelet counts and lower concentrations of complement factor 3 and blood urea nitrogen but higher serum albumin concentrations. Vegans did not differ from nonvegetarians in functional immunocompetence assessed as mitogen stimulation or natural killer cell cytotoxic activity.

PMID: 10479236

  Compared with non-vegetarians, Western vegetarians have a lower mean BMI (by about 1 kg/m2), a lower mean plasma total cholesterol concentration (by about 0.5 mmol/l), and a lower mortality from IHD (by about 25%). They may also have a lower risk for some other diseases such as constipation, diverticular disease, gallstones and appendicitis. No differences in mortality from common cancers have been established. There is no evidence of adverse effects on mortality. Much more information is needed, particularly on other causes of death, other morbidity including osteoporosis, and long-term health in vegans. The evidence available suggests that widespread adoption of a vegetarian diet could prevent approximately 40,000 deaths from IHD in Britain each year.

PMID: 10466166

  Endogenous oestradiol is strongly associated with breast cancer risk but its determinants are poorly understood. To test the hypothesis that vegetarians have lower plasma oestradiol and higher sex hormone-binding globulin (SHBG) than meat-eaters we assayed samples from 640 premenopausal women (153 meat-eaters, 382 vegetarians, 105 vegans) and 457 post-menopausal women (223 meat-eaters, 196 vegetarians, 38 vegans). Vegetarians and vegans had lower mean body mass indices (BMI) and lower plasma cholesterol concentrations than meat-eaters, but there were no statistically significant differences between meat-eaters, vegetarians and vegans in pre- or post-menopausal plasma concentrations of oestradiol or SHBG. Before adjusting for BMI there were small differences in the direction expected, with the vegetarians and vegans having higher SHBG and lower oestradiol (more noticeable amongst post-menopausal women) than the meat-eaters. These small differences were essentially eliminated by adjusting for BMI. Thus this study implies that the relatively low BMI of vegetarians and vegans does cause small changes in SHBG and in post-menopausal oestradiol, but that the composition of vegetarian diets may not have any additional effects on these hormones.

PMID: 10424753

  OBJECTIVE: This study was undertaken to determine if African-American strict vegetarians (vegans) exhibit lower blood pressure (BP) and a more favorable serum lipid profile than their lacto-ovo vegetarian (LOV) counterparts, and if plasma ascorbic acid (AA) concentrations could explain any group differences in these cardiovascular disease (CVD) risk factors.
  METHODS: Habitual dietary intake, anthropometric characteristics, blood pressure, and blood lipids and ascorbic acid concentrations were determined in African-American study participants (male vegans, n = 14, age = 45.6 years; male LOV, n = 49, age = 49.8; female vegans, n = 31, age = 51.1, female LOV, n = 94, age = 52.1) recruited from Seventh-Day Adventist Churches in several cities in the northeastern United States.
  RESULTS: Body mass index (BMI) was significantly lower in the vegans (24.7 +/- 1.9 kg/m2) compared to LOV (26.4 +/- 0.45 kg/m2). There were no diet or gender differences in BP. Serum total cholesterol (3.75 +/- 0.12 vs. 4.51 +/- 0.10 mmol/L), LDL-cholesterol (2.06 +/- 0.13 vs. 2.65 +/- 0.09 mmol/l), and triglycerides (0.94 +/- 0.07 vs. 1.17 +/- 0.04 mmol/L) were significantly (p < 0.05) lower in vegans compared to LOV, but there were no dietary group differences in HDL-C. The ratio of total to HDL-cholesterol was significantly lower in vegans than in LOV (3.0 +/- 0.13 vs. 3.7 +/- 0.13). There were no dietary group differences in plasma AA concentrations. However, in the entire sample, plasma AA was inversely associated with BP (SBP: r = -0.46, p < 0.001, DBP: r = -0.32, p < 0.001), but unrelated to the serum lipid concentrations.
  CONCLUSION: African-American vegans exhibit a more favorable serum lipid profile than lacto-ovo-vegatarians and plasma AA is inversely related to BP in African-American vegetarians but does not explain any of the differences in CVD risk factors between vegans and lacto-ovo vegetarians.

PMID: 9791838

  OBJECTIVE: To examine the associations of diet and other lifestyle factors with body mass index (BMI) using data from the Oxford Vegetarian Study.
  SUBJECTS: 1914 male and 3378 female non-smokers aged 20-89 y at recruitment to the study.
  MEASUREMENTS: All subjects completed a diet/lifestyle questionnaire at recruitment giving details of their usual diet and other characteristics including height and weight, smoking and drinking habits, amount of exercise, occupation and reproductive history. Answers to the food frequency questionnaire were used to classify subjects as either meat eaters or non-meat eaters, and to estimate intakes of animal fat and dietary fibre. Subjects were further classified according to their alcohol consumption, exercise level, social class, past smoking habits and parity.
  RESULTS: Mean BMI was lower in non-meat eaters than in meat eaters in all age groups for both men and women. Overall age-adjusted mean BMIs in kg/m2 were 23.18 and 22.05 for male meat eaters and non-meat eaters respectively (P < 0.0001) and 22.32 and 21.32 for female meat eaters and non-meat eaters respectively (P < 0.0001). In addition to meat consumption, dietary fibre intake, animal fat intake, social class and past smoking were all independently associated with BMI in both men and women; alcohol consumption was independently associated with BMI in men, and parity was independently associated with BMI in women. After adjusting for these factors, the differences in mean BMI between meat eaters and non-meat eaters were reduced by 36% in men and 31% in women.
  CONCLUSIONS: Non-meat eaters are thinner than meat eaters. This may be partly due to a higher intake of dietary fibre, a lower intake of animal fat, and only in men a lower intake of alcohol.

PMID: 9622343

  In participants of a comprehensive residential three month yoga and mediation training programme living on a low fat lacto-vegetarian diet changes in cardiovascular risk factors and hormones were studied. Substantial risk factor reduction was found. Body mass index, total serum and LDL cholesterol, fibrinogen, and blood pressure were significantly reduced especially in those with elevated levels. Urinary excretion of adrenaline, noradrenaline, dopamine, aldosterone, as well as serum testosterone and luteinizing hormone levels were reduced, while cortisol excretion increased significantly.

PMID: 9401632

  In this paper, the shortterm influence of a lactovegetarian diet on selected laboratory parameters and motivation of patients in comparison to a conventional, fat-modified and cholesterol-lowered, omnivorous diet during a clinical rehabilitation treatment should be examined. During an average period of 24.2 days the total cholesterol and the LDL-cholesterol fell for a group of 151 patients who had volunteered to sustain a vegetarian diet for the duration of the clinical rehabilitation, significantly higher by a medium level of 31.1 mg/dl (12.5%) versus 16.9 mg/dl (7%) respectively 27.7 mg/dl (14.5%) versus 11.8 mg/dl (6.5%), as compared to a randomly selected control group of 151 patients. The reductions within the groups were also significant. All of the other laboratory parameters such as lipoprotein (a), fibrinogen, uric acid, triglycerides, and HDL-cholesterol did not exhibit any diet-related changes. The weight of the adipose patients could be reduced very significantly through a reduction diet consisting of lactovegetarian food by an average of 3.2 kg versus 1.6 kg (as in the case of the normal, omnivorous diet). All of the dependent values, i.e., circumference of abdomen and hip, and "body-mass-index" (BMI) showed the same highly significant differences. Even after 1 year approximately two-thirds of the patients of the vegetarian group chose the reduction of meat and meat-products in their diet, of which merely a small part, 5.3%, were faithful to the pure lactovegetarian food. Essentially, the favorable effects on the lipid values persisted. The positive effects on the lipid values, the weight, and the motivation of the group of patients with the lactovegetarian diet allow the general recommendation of this diet for heart patients in the course of their clinical rehabilitation.

PMID: 8767366

  OBJECTIVE: To compare nutrient intakes between vegetarians and nonvegetarians with similar health practices, and to assess relationships with eating behavior scores from the Three-Factor Eating Questionnaire.
  DESIGN: Survey.
  SETTING: Metropolitan area in western Canada.
  SUBJECTS: Subjects (n = 45) were participants in a study comparing subclinical menstrual disturbances between vegetarians and nonvegetarians. To be included, women had to be 20 to 40 years old, be weight stable with a body mass index (BMI; kg/m2) of 18 to 25, be a nonsmoker, exercise 7 hours a week or less, consume one alcoholic drink or less a day, and not be using oral contraceptives. Nonvegetarians (n = 22) ate red meat three times a week or more, and vegetarians (n = 23, 8 vegans and 15 lactovegetarians) had excluded all meat, fish, and poultry for 2 years or more.
  MAIN OUTCOME MEASURES: Nutrient intake assessed by three 3-day diet records; supplement use; body composition; and dietary restraint (conscious limitation of food intake), disinhibition, and hunger assessed by the Three-Factor Eating Questionnaire.
  STATISTICAL ANALYSES PERFORMED: Anthropometric variables, nutrient intakes, and eating behavior scores were compared between vegetarians and nonvegetarians using unpaired t tests, and among vegans, lactovegetarians, and nonvegetarians using one-way analysis of variance and Duncan's test. Supplement use was compared using chi 2 analysis. The Pearson correlation coefficient was used to evaluate relationships between variables.
  RESULTS: Diets of all women adhered closely to current nutrition recommendations. Vegetarians had lower protein and cholesterol intakes and higher percentage of energy as carbohydrate, ratio of polyunsaturated fat to saturated fat (P:S ratio), and fiber intake than nonvegetarians. Vegetarians had lower riboflavin, niacin, vitamin B-12, zinc, and sodium intakes and higher folate, vitamin C, and copper intakes. However, many differences were not apparent between the subgroup of lactovegetarians and nonvegetarians (their P:S ratios and carbohydrate, fiber, riboflavin, folate, vitamin C, and copper intakes were similar). In contrast, differences existed between the lactovegetarian and the vegan subgroups. Supplement use was similar between groups, except for greater vitamin C use by vegetarians. Vegetarians were leaner than nonvegetarians, had lower restraint scores, and had significant associations between restraint and BMI (r = .49; P < .05) and energy per kilogram body weight (r = -.60; P < .01).
  APPLICATIONS/CONCLUSIONS: Current nutrition recommendations can be attained by vegetarians and nonvegetarians alike, but nutrient intakes cannot be inferred from dietary pattern. In this study, the intakes of health-conscious nonvegetarians and lactovegetarians were more similar than the intakes of lactovegetarians and vegans. Vegans' calcium and vitamin B-12 intakes may need attention. Vegetarians' lower restraint scores suggest that they are not at increased risk for eating disorders.

PMID: 7852684