Sensitivity and Specificity issues regarding BMI thresholds By Steven B. Halls, MD FRCPC Many medical tests have issues with sensitivity and specificity. What do these words mean? Sensitivity: is the ability to correctly detect disease. Specificity: is the ability to avoid calling Normal things as disease.   A perfect medical test would have 100% sensitivity […]

Comments and Key points This is an article about anorexia BMI measurements. In addition to its main content about anorexia, it also included tables of data of German BMI measurements at various ages. The 10th percentile data from the German National Nutrition Survey (1985 to 1989) is shown in the chart below. My point for […]

How did data from Brazil and adolescents for BMI body mass index cutoffs for obesity and overweight happen? This study measured body fat percentages, using the Tanita body fat monitor scale, which uses foot-to-foot bioelectric impedence technique. The sample population is Brazilian adolescents. They used body fat percentages, 25% for boys, 30% for girls, as […]

Compare "Marginally Overweight" to CDC’s BMI=25 By Steven B. Halls, MD In an effort to maintain some compatibility between the halls.md v2 method and the standard CDC & WHO definition of "overweight", the halls.md v2 method has re-introduced the phrase "marginally overweight", to refer to BMI values around the magic number of 25 kg/m2. If […]

Comments about weight categories, body mass index, overweight and sexual frequency Very interesting. It turns out that women in the BMI range of 25 to 30 are having more sex than women with BMI <25.   BMI <25 "Normal" BMI 25-30 "Overweight" BMI >30 "Obese" Had any sex, ever? * 87.4% 92.5% 91.5% In past […]

Comments about the average body mass index changing with age in France, showing average BMI values This article documents the French population’s body mass index. France has a population with less obesity than America. A graph of BMI centiles is shown below: I show this graphic because it illustrates the curve shapes that occur in […]

Comments regarding child obesity definition with BMI Their data source was 1978-1980 in The Netherlands. Children’s percentiles of Body Mass Index showed this distribution. The authors believe this BMI data is useful, because it apparently dates back to a time when there was not much obesity in the Netherlands children’s population. As just pointed out, […]

Comments and Key points about this article on the range of body mass index values This article shows tables of data comparing American’s Body Mass Index (BMI) in 1976-80 versus 1988-94. The data is ‘late 70s’ compared to ‘late 80s’: Median BMI Men Women   1976-80 1988-94 1976-80 1988-94 Age 20 to 29 23.7 24.3 […]

Body Surface Area Calculation standard, continued… Back to BSA report page 3 of report by Thanh Vu, B.Sc. (pharm), ( click here to go to the Body Surface Area BSA calculator ) Calculating BSA in obese individuals is more controversial, with each center developing its own policy.  Robin O’Brien, the drug information pharmacist at the […]

Comments about their body mass index cut offs of BMI This article reported on the Danish population, and suggested suitable body mass index cut-offs thresholds to define Overweight and Obesity. (Actually, the article labelled these as “Moderate overweight” and “Extreme overweight”). Anyway, here are the thresholds suggested. Overweight Sensitivity Specificity Men 26.1 77.5% 84.7% 27.2 […]

Body Surface Area Standard formula for Calculating doses A report by Thanh Vu, B.Sc. (pharm),  Dept. of Pharmacy, Cross Cancer Institute. 1999. ( click here to go to the Body Surface Area BSA calculator ) Variation between individuals in response to chemotherapy can be of great clinical significance.  A successful chemotherapy program should produce a […]

Showing real data, the 85th and 95th percentiles of Body Mass Index at various ages This data from the NHANES I study ( 1971-1974) is now out-of-date, because more recent studies, NHANES II and NHANES III have been performed. However, this was the data that was originally suggested to establish "overweight" and "obesity" thresholds, at […]

Comments and Key points Frankly, this is a difficult study to read and understand. It’s results indicate that, for young adults in the United Kingdom (UK), at Age 18 – women are more overweight than men, but this reverses by Age 23 – when men are more overweight than women. But the numbers of of […]

Comments and Key points, about body mass index, of child obesity. This seems like a good article, and it does discuss child obesity and BMI, but upon closer inspection it was not helpful. It’s key limitation is that it only examined 7-year old children, not other ages. It defined "true obesity" as children with body […]

Standardization of Body Surface Area Calculations Back to BSA report page 4 of a report by Thanh Vu, B.Sc. (pharm),  ( click here to go to the Body Surface Area BSA calculator ) Other methods for dose calculations that do not rely on direct patient monitoring have been developed using Pharmacokinetic (PK) information.  The best […]

Child body mass index, and about the childrens BMI charts in this article This is a review of an article about child body mass index, which showed some rather useful charts, plotting the 85th percentile’s of children’s BMI, from six different nationalities. And in the chart below, the blue line (boys) and pink line (girls) […]

Womens BMI body mass index changes with age A chart showing the Body Mass Index of Women, changing with age. Quite interesting, really. I bet you haven’t seen this chart anywhere else! Notice the "median" BMI value, which is the 50th percentile Red line. Compare it to the CDC definition of "Overweight" at BMI of […]

References for Body Surface Area Back to BSA report page 5. A report by Thanh Vu, B.Sc. (pharm), ( click here to go to the Body Surface Area BSA calculator ) References Favier M., de CAzanove F, Saint-Martin F, Bressolle F,  Preventing medication errors in antineoplastic therapy.  American Journal of Hospital Pharmacy.   51:832-833, 1994. […]

Comments about body mass index in anorexia nervosa This article has lots of good data, showing the BMI levels of patients with anorexia nervosa, at diagnosis, and at long term follow-up throughout their adult lives. I’ve referenced this article because it has a chart showing the BMI percentiles of the German population, using data from […]

Comments about teens who self report height weight and body mass index An adolescent’s self-reported height and weight, is OK to use in calculating BMI and judging obesity. Their study found 96% of teens were correctly classified as obese or not obese, using the 95th percentile cutoff values of the CDC growth charts. Neither teens […]

Comments and Key points This article has data concerning the body fat percentages of non-European rural persons from several different regions of the world. Unfortunately, it’s quite difficult to learn anything really specific or definitive from their article. For example, the graph below shows % body fat versus Body mass index, but the lines are […]

My summary. Body mass index cut off points were established via these publications This article has the most comprehensive summary of body mass index thresholds, to define obesity and overweight. It is an excellent source of references. It is available for viewing as free full text at http://www.ajcn.org/cgi/content/full/72/5/1074. However, as you read this article, it […]

Comments on children and adult Body mass index BMI cutoffs of overweight and obesity, regarding age 18 This article says "the International Task Force workshop… defining overweight and obesity at childhood percentiles that correspond to the adult values… 25 and 30 kg/m2 respectively, correspond to the 80th and 95th percentiles of the National Center for […]

Body Mass Index screening in Children and adolescents, done in a scientific way. Fabulous article. Although it’s based in Australia, one of its conclusions is that the CDC overweight criteria for Americans, is also suitable for Australia. The article supports the CDC criteria for children, using the 85th percentile of BMI for defining "at risk […]

Comments about this study of the body mass index of children and centile charts I’ve included this article in my collection, because it shows charts of body mass index of children, comparing Scottish and French populations. The French data is older (1956-1979) whereas the Scottish data is newer ( 1989-1991), so the charts really show […]

Official confirmation. Age 18 BMI cutoffs of Body Mass Index were applied to all adults as overweight and obesity criteria. The full text of this article is available free at British Medical Journal online. The authors found 6 diverse nations having good data about body mass index in children. It averaged all their data to […]

Title of article: The WHO makes a reassessment of the appropriate body-mass index for Asian populations. Authors: Choo V. Journal: The Lancet, Jul 2002 20;360(9328):235 Abstract This is a short communication in the Lancet, without an abstract. Here is the major quote: "The range for acceptable, normal, or optimum body-mass index (BMI) for Asian populations […]

Title of article: Body mass index and child obesity: are we nearing a definition? Authors: Poskitt, EM Journal: Acta Paediatr, May 2000;89(5):507- 509 Abstract There is no published abstract for this article. (It is a commentary on another article in Acta Paediatrica.) I have therefore provided this short abstract: Several paragraphs discuss the need for […]