The ultimate measure of body shape and size, lifestyle and eating pattern is the answer to the following question: Will it (the eating pattern, lifestyle or body makeup) impact my overall risk of mortality? Health problems like the numbered stack I’ve listed below might arise, and there are well-know relationships between diet, fat distribution patterns and specific disease entities, but is there a healthy overweight category? Can someone have a BMI of 28, exercise regularly and still be considered healthy with a low risk of mortality? Maybe. Or maybe not.
By implication, the categories of BMI don’t lend any apparent wiggle room. That is to say, the overweight category, BMI 25 to 29.9, might seem innocent (since many if not the majority of the population now falls into this category) but is there a basis for stating that being overweight is unhealthy to the point of increasing the chance of mortality? More concrete than that, if my BMI is 26 am I at any more risk of death than some0ne with a BMI of 24?
Taking the liberal skeptics approach, if not, then all this wrangling to call more than half of all Westerners overweight and by implication, unhealthy, is an exercise in futility. A persons diet, body habitus, fat distribution and lifestyle may increase the risk of certain disease processes, but if it doesn’t impact mortality is it worth pursuing? Risking an argument that invokes quality of life questions and the economics of health care, if I'm overweight and I have a mortality rate the same as someone not overweight, don't preach weight loss to me.
According to widely held beliefs, when comparing those at ideal BMI (18.5 to 24.9), to obese individuals (BMI greater than 30) the risk of chronic medical problems attributed to that increase in weight is rather large. What follows is a number of health problems associated with a BMI greater than 30:
1. Diabetes
2. Hypertension
3. Heart disease
4. Stroke
5. Cancer
6. Decreased life expectancy
7. Sleep apnea
However, lets examine the most recent mortality data.
In a study[i] published in the Journal of the American Medical Association on April 20th 2005, Katherine Flegal and others examined data from the National Health and Nutrition Survey (NHANES) to report on excess mortality due to overweight and obesity. NHANES is a cross-section of Americans who are periodically interviewed and examined by representatives from the National Center for Health Statistics. The authors took data from NHANES I (1971-1975), NHANES II (1976-1980) and NHANES III (1988-1994) examining mortality data from each of the three groups sampled.
The first noteworthy trend found by comparing all three NHANES data sets, is a growing percent of individuals in America (and probably most of Western society) with a BMI greater than 35. In NHANES I the percent of individuals with a BMI greater than 35 was just 4.4%, but by NHANES III that number had risen to 8.3%.
The shocker in this study wasn’t that the excess mortality due to obesity wasn’t statistically significant (except for a BMI greater than or equal to 35); the jolt was that in the overweight category (BMI from 25 to 29.9) the actual excess mortality was less than zero. An excess mortality less than zero is interpreted to mean that relative to a normal BMI (18.5 to 24.9), those individuals categorized as overweight had a lower relative risk of mortality than those individuals in the normal BMI category.
In other words, the proposed health impact of overweight might not be considered unhealthy. And extending that thought, it might offer a benefit. According to this study, the excess weight appears to offer a very low risk of mortality to those overweight individuals, and might, in the current environment, offer an advantage. While the findings of a lower rate of death in the overweight category is tantamount to blasphemy, the study’s lead author hails from the National Center for Health Statistics, Centers for Disease Control and Prevention. More Later.
[i] Flegal et al., Excess Deaths Associated With Underweight, Overweight, and Obesity JAMA, April 20th 2005, Volume 293, pages 1861-67.
By implication, the categories of BMI don’t lend any apparent wiggle room. That is to say, the overweight category, BMI 25 to 29.9, might seem innocent (since many if not the majority of the population now falls into this category) but is there a basis for stating that being overweight is unhealthy to the point of increasing the chance of mortality? More concrete than that, if my BMI is 26 am I at any more risk of death than some0ne with a BMI of 24?
Taking the liberal skeptics approach, if not, then all this wrangling to call more than half of all Westerners overweight and by implication, unhealthy, is an exercise in futility. A persons diet, body habitus, fat distribution and lifestyle may increase the risk of certain disease processes, but if it doesn’t impact mortality is it worth pursuing? Risking an argument that invokes quality of life questions and the economics of health care, if I'm overweight and I have a mortality rate the same as someone not overweight, don't preach weight loss to me.
According to widely held beliefs, when comparing those at ideal BMI (18.5 to 24.9), to obese individuals (BMI greater than 30) the risk of chronic medical problems attributed to that increase in weight is rather large. What follows is a number of health problems associated with a BMI greater than 30:
1. Diabetes
2. Hypertension
3. Heart disease
4. Stroke
5. Cancer
6. Decreased life expectancy
7. Sleep apnea
However, lets examine the most recent mortality data.
In a study[i] published in the Journal of the American Medical Association on April 20th 2005, Katherine Flegal and others examined data from the National Health and Nutrition Survey (NHANES) to report on excess mortality due to overweight and obesity. NHANES is a cross-section of Americans who are periodically interviewed and examined by representatives from the National Center for Health Statistics. The authors took data from NHANES I (1971-1975), NHANES II (1976-1980) and NHANES III (1988-1994) examining mortality data from each of the three groups sampled.
The first noteworthy trend found by comparing all three NHANES data sets, is a growing percent of individuals in America (and probably most of Western society) with a BMI greater than 35. In NHANES I the percent of individuals with a BMI greater than 35 was just 4.4%, but by NHANES III that number had risen to 8.3%.
The shocker in this study wasn’t that the excess mortality due to obesity wasn’t statistically significant (except for a BMI greater than or equal to 35); the jolt was that in the overweight category (BMI from 25 to 29.9) the actual excess mortality was less than zero. An excess mortality less than zero is interpreted to mean that relative to a normal BMI (18.5 to 24.9), those individuals categorized as overweight had a lower relative risk of mortality than those individuals in the normal BMI category.
In other words, the proposed health impact of overweight might not be considered unhealthy. And extending that thought, it might offer a benefit. According to this study, the excess weight appears to offer a very low risk of mortality to those overweight individuals, and might, in the current environment, offer an advantage. While the findings of a lower rate of death in the overweight category is tantamount to blasphemy, the study’s lead author hails from the National Center for Health Statistics, Centers for Disease Control and Prevention. More Later.
[i] Flegal et al., Excess Deaths Associated With Underweight, Overweight, and Obesity JAMA, April 20th 2005, Volume 293, pages 1861-67.
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