Hood 2019 Nutr Diabetes

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Publications in the MiPMap
Hood K, Ashcraft J, Watts K, Hong S, Choi W, Heymsfield SB, Gautam RK, Thomas D (2019) Allometric scaling of weight to height and resulting body mass index thresholds in two Asian populations. Nutr Diabetes 9:2. doi: 10.1038/s41387-018-0068-3.

» PMID: 30683839 Open Access

Hood K, Ashcraft J, Watts K, Hong S, Choi W, Heymsfield SB, Gautam RK, Thomas D (2019) Nutr Diabetes

Abstract: BACKGROUND: Body mass index (BMI) represents a normalization of weight to height and is used to classify adiposity. While the capacity of BMI as an adiposity index has been experimentally validated in Caucasians, but there has been little testing Asian populations.

METHODS: To determine whether weight scales to height squared in Asian Indians across the general population and in Asian Indian tribes an allometric analysis on the power law model, W =αHβ, where W is weight (kg) and H is height (m) was performed on cross-sectional weight and height data from India (N = 43,880) collected through the Anthropological Survey of India. The database contained males 18-84 years of age spanning 161 districts of 14 states and including 33 different tribes (N = 5,549). Models were developed that were unadjusted and adjusted for tribe membership. The Korean National Health and Nutrition Examination Survey (KNHANES) was used to compare to height-weight data from the Anthropological Survey of India and to calculate BMI thresholds for obesity status using a receiver operating characteristic.

RESULTS: The unadjusted power was β = 2.08 (s = 0.02). The power for the general population (non-tribal) was β = 2.11 (s = 0.02). Powers when adjusted for tribe ranged from 1.87 to 2.35 with 24 of the 33 tribes resulting in statistically significant (p < 0.05) differences in powers from the general population. The coefficients of the adjusted terms ranged from -0.22 to 0.26 and therefore the scaling exponent does not deviate far from 2. Thresholds for BMI classification of overweight in the KNHANES database were BMI = 21 kg/m2 (AUC = 0.89) for males 18 kg/m2 (AUC = 0.97) for females. Obesity classification was calculated as BMI = 26 kg/m2 (AUC = 0.81) and 23 kg/m2 (AUC = 0.83) for females.

CONCLUSIONS: Our study confirms that weight scales to height squared in Asian Indian males even after adjusting for tribe membership. We also demonstrate that optimal BMI thresholds are lower in a Korean population in comparison to currently used BMI thresholds. These results support the application of BMI in Asian populations with potentially lower thresholds.

Bioblast editor: Gnaiger E

Healthy reference population     Body mass excess         BFE         BME cutoffs         BMI         H         M         VO2max         mitObesity drugs

From BMI to BME

Work in progress by Gnaiger E 2020-02-10 linked to a preprint in preparation on BME and mitObesity.
Figure 1: Body mass as a function of height. The full lines show the allometric relation of the healthy reference population with body mass M° (BME°=0.0; green), at a body mass excess of BME=0.2 (M0.2=1.2M°; orange), and at BME=-0.1 (M-0.1=0.9M°; blue). Symbols are from Table 1 of Hood et al (2019) with the years of measurement in parentheses. Healthy and active adult males (15–54 years) were studied in 34 tribal populations from 14 of the 29 states of India (N=5549) and nontribal populations in each state (N=38331) from 1965 to 1970 and from 2005 to 2006. The dashed line connects the average of 5089 women and 3849 men of South Korea collected from 2007–2009 (KNHANES IV) and 2010–2012 (KNHANES V).
Hood et al (2019) suggest that their study 'confirms that weight scales to height squared'. Do their and many similar studies qualify for more than the trivial statement: 'Without reference to a rational (mechanistic, physiolgocial, evolutionary, ..) hypothesis, the relationship observed between body mass and height in this particular database does not provide evidence for or against a specific exponent in the allometric body mass/height power function'. The assumption that body mass scales to height squared in various present-day populations has no rational foundation (this challenges the corresponding working hypotesis). It is important, therefore, to define the fundamental hypothesis, upon which a judgment of the power function with an exponent of two carries heuristic relevance. A 'fundamental' hypothesis cannot be gauged on mere convention and historical track record (think of the religious and scientific believes in the heliocentric world-view). An allometric power function can be calculated from any data collected recently on any population of the world. So what? There is a solidly documented global trend towards increased overweight and obesity (##). Importantly, however, there is strong evidence that different socio-economic subgroups of a population (women versus men, children versus adults, large versus small, affluent versus poor) are affected differently by the general trend towards obesity. Consequently, the allometric height exponent A (A=2 in the BMI paradigm) observed in any current study reveals interesting information on the differential trends towards obesity, without any relevance on the general anthropomorphic concept of the BMI.
Figure 2: Body mass (a), and body mass index, BMI (b) as a function of height. Data from the Indian Academy of Pediatrics Growth Charts Committee 2015 Indian Pediatr, Hood et al (2019), and Bosy-Westphal et al (2009). South Korean women have a lower BMI than men, but are more displaced from the BME=0.2 cutoff line. (c) BMI as a function of body mass excess, BME. At any constant height, the BMI increases linearly with BME (grey lines), but at constant BME the BMI increases as a function of height, from 15 kg·m-2 at 1.2 m/x to 20 kg·m-2 at 1.7 m/x.

The relevant questions and directions of research are: (1) Define the allometric healthy reference population (HRP). WHO standars provide an invaluable resource. (2) Forge WHO standards and additional historical resources into basline parameters. These need to be validated across:
  1. Evolutionary background: the bias of different heights in the adult population is fundamentally explained by the BME-concept.
  2. Gender or sex: BME cutoff points are valid equally in women and men, in contrast to an unresolved debate on sex-specific BMI cutoff points, particularly in Asian populations.

Publications: BME and height

» Height of humans
Bosy-Westphal 2009 Br J NutrBosy-Westphal A, Plachta-Danielzik S, Dörhöfer RP, Müller MJ (2009) Short stature and obesity: positive association in adults but inverse association in children and adolescents. Br J Nutr 102:453-61.
De Onis 2007 Bull World Health Organizationde Onis M, Onyango AW, Borghi E, Siyam A, Nishida C, Siekmann J (2007) Development of a WHO growth reference for school-aged children and adolescents. Bull World Health Organization 85:660-7.
Gnaiger 2019 MiP2019
Erich Gnaiger
OXPHOS capacity in human muscle tissue and body mass excess – the MitoEAGLE mission towards an integrative database (Version 6; 2020-01-12).
Hood 2019 Nutr DiabetesHood K, Ashcraft J, Watts K, Hong S, Choi W, Heymsfield SB, Gautam RK, Thomas D (2019) Allometric scaling of weight to height and resulting body mass index thresholds in two Asian populations. Nutr Diabetes 9:2. doi: 10.1038/s41387-018-0068-3.
Indian Academy of Pediatrics Growth Charts Committee 2015 Indian PediatrIndian Academy of Pediatrics Growth Charts Committee, Khadilkar V, Yadav S, Agrawal KK, Tamboli S, Banerjee M, Cherian A, Goyal JP, Khadilkar A, Kumaravel V, Mohan V, Narayanappa D, Ray I, Yewale V (2015) Revised IAP growth charts for height, weight and body mass index for 5- to 18-year-old Indian children. Indian Pediatr 52:47-55.
Zucker 1962 Committee on Biological Handbooks, Fed Amer Soc Exp BiolZucker TF (1962) Regression of standing and sitting weights on body weight: man. In: Growth including reproduction and morphological development. Altman PL, Dittmer DS, eds: Committee on Biological Handbooks, Fed Amer Soc Exp Biol:336-7.

MitoPedia: BME and mitObesity

» Body mass excess and mitObesity | BME and mitObesity news | Summary |

BME cutoff pointsBME cutoffObesity is defined as a disease associated with an excess of body fat with respect to a healthy reference condition. Cutoff points for body mass excess, BME cutoff points, define the critical values for underweight (-0.1 and -0.2), overweight (0.2), and various degrees of obesity (0.4, 0.6, 0.8, and above). BME cutoffs are calibrated by crossover-points of BME with established BMI cutoffs.
Body fat excessBFEIn the healthy reference population (HRP), there is zero body fat excess, BFE, and the fraction of excess body fat in the HRP is expressed - by definition - relative to the reference body mass, M°, at any given height. Importantly, body fat excess, BFE, and body mass excess, BME, are linearly related, which is not the case for the body mass index, BMI.
Body massm [kg]; M [kg·x-1]The body mass, M, is the mass (kilogram [kg]) of an individual (object) [x] and is expressed in units [kg/x]. Whereas the body weight changes as a function of gravitational force (you are weightless at zero gravity; your floating weight in water is different from your weight in air), your mass is independent of gravitational force, and it is the same in air and water.
Body mass excessBMEThe body mass excess, BME, is an index of obesity and as such BME is a lifestyle metric. The BME is a measure of the extent to which your actual body mass, M [kg/x], deviates from M° [kg/x], which is the reference body mass [kg] per individual [x] without excess body fat in the healthy reference population, HRP. A balanced BME is BME° = 0.0 with a band width of -0.1 towards underweight and +0.2 towards overweight. The BME is linearly related to the body fat excess.
Body mass indexBMIThe body mass index, BMI, is the ratio of body mass to height squared (BMI=M·H-2), recommended by the WHO as a general indicator of underweight (BMI<18.5 kg·m-2), overweight (BMI>25 kg·m-2) and obesity (BMI>30 kg·m-2). Keys et al (1972; see 2014) emphasized that 'the prime criterion must be the relative independence of the index from height'. It is exactly the dependence of the BMI on height - from children to adults, women to men, Caucasians to Asians -, which requires adjustments of BMI-cutoff points. This deficiency is resolved by the body mass excess relative to the healthy reference population.
ComorbidityComorbidities are common in obesogenic lifestyle-induced early aging. These are preventable, non-communicable diseases with strong associations to obesity. In many studies, cause and effect in the sequence of onset of comorbidities remain elusive. Chronic degenerative diseases are commonly obesity-induced. The search for the link between obesity and the etiology of diverse preventable diseases lead to the hypothesis, that mitochondrial dysfunction is the common mechanism, summarized in the term 'mitObesity'.
Healthy reference populationHRPA healthy reference population, HRP, establishes the baseline for the relation between body mass and height in healthy people of zero underweight or overweight, providing a reference for evaluation of deviations towards underweight or overweight and obesity. The WHO Child Growth Standards (WHO-CGS) on height and body mass refer to healthy girls and boys from Brazil, Ghana, India, Norway, Oman and the USA. The Committee on Biological Handbooks compiled data on height and body mass of healthy males from infancy to old age (USA), published before emergence of the fast-food and soft-drink epidemic. Four allometric phases are distinguished with distinct allometric exponents. At heights above 1.26 m/x the allometric exponent is 2.9, equal in women and men, and significantly different from the exponent of 2.0 implicated in the body mass index, BMI [kg/m2].
Height of humansh [m]; H [m·x-1]The height of humans, h, is given in SI units in meters [m]. Humans are countable objects, and the symbol and unit of the number of objects is N [x]. The average height of N objects is, H = h/N [m/x], where h is the heights of all N objects measured on top of each other. Therefore, the height per human has the unit [m·x-1] (compare body mass [kg·x-1]). Without further identifyer, H is considered as the standing height of a human, measured without shoes, hair ornaments and heavy outer garments.
Lengthl [m]Length l is an SI base quantity with SI base unit meter m. Quantities derived from length are area A [m2] and volume V [m3]. Length is an extensive quantity, increasing additively with the number of objects. The term 'height' h is used for length in cases of vertical position (see height of humans). Length of height per object, LUX [m·x-1] is length per unit-entity UX, in contrast to lentgth of a system, which may contain one or many entities, such as the length of a pipeline assembled from a number NX of individual pipes. Length is a quantity linked to direct sensory, practical experience, as reflected in terms related to length: long/short (height: tall/small). Terms such as 'long/short distance' are then used by analogy in the context of the more abstract quantity time (long/short duration).
MitObesity drugsBioactive mitObesity compounds are drugs and nutraceuticals with more or less reproducible beneficial effects in the treatment of diverse preventable degenerative diseases implicated in comorbidities linked to obesity, characterized by common mechanisms of action targeting mitochondria.
ObesityObesity is a disease resulting from excessive accumulation of body fat. In common obesity (non-syndromic obesity) excessive body fat is due to an obesogenic lifestyle with lack of physical exercise ('couch') and caloric surplus of food consumption ('potato'), causing several comorbidities which are characterized as preventable non-communicable diseases. Persistent body fat excess associated with deficits of physical activity induces a weight-lifting effect on increasing muscle mass with decreasing mitochondrial capacity. Body fat excess, therefore, correlates with body mass excess up to a critical stage of obesogenic lifestyle-induced sarcopenia, when loss of muscle mass results in further deterioration of physical performance particularly at older age.
VO2maxVO2max; VO2max/MMaximum oxygen consumption, VO2max, is and index of cardiorespiratory fitness, measured by spiroergometry on human and animal organisms capable of controlled physical exercise performance on a treadmill or cycle ergometer. VO2max is the maximum respiration of an organism, expressed as the volume of O2 at STPD consumed per unit of time per individual object [mL.min-1.x-1]. If normalized per body mass of the individual object, M [kg.x-1], mass specific maximum oxygen consumption, VO2max/M, is expressed in units [mL.min-1.kg-1].

Labels: MiParea: Gender, Developmental biology, Exercise physiology;nutrition;life style  Pathology: Obesity 

Organism: Human 

Preparation: Intact organism 

BMI, BME, Height