the Natural Condition

Being overweight is bad for your health, right? With all the talk of the American obesity epidemic and the consequent rise in diabetes and associated ailments, combined with the fact that cardiovascular disease is known to be the leading killer in America and is exacerbated by lack of exercise, most people assume that excess poundage will lead to a shortened life span. While the information I am about to divulge is not new, I would like to summarize the findings of a 2005 study that, very shockingly, discovered a decrease in the death rate for “overweight” persons.

In 2005, JAMA published an article by Flagel et al. of the National Center for Health Statistics (a division of the CDC) and the National Cancer Institute entitled “Excess Deaths Associated With Underweight, Overweight, and Obesity.” The authors sought to answer broad questions about the impact of weight (BMI) on mortality. They used 3 of the National Health and Nutrition Examination Surveys (NHANES), which comprise data on over 35,000 people dating as far back as 1971. They grouped patients into 4 categories of interest, with one control, all based on BMI. They used the national standards for BMI classification:

1. <18.5 : Underweight
2. 18.5 - <25 : Normal (control)
3. 25 - <30 : Overweight
4. 30 - <35 : Obese
5. ≥35 : Morbidly Obese

When performing their analyses, each group was controlled for known confounding factors to mortality, such as smoking. The table below outlines their findings for relative risk of death by age group and BMI. A RR<1 means that a population is at less of a risk for dying than the Normal-weight group, RR>1 means they do worse.

^{Relative risk of death by age group and BMI. Image courtesy of JAMA.}

What we see in this table is that both the Obese and Underweight cohorts have substantially higher relative risks than Normal-weight individuals, and more markedly so in younger age groups. The big, and unanticipated, anomaly is the Overweight cohort, which exhibited a relative risk <1 in every case. Flagel et al. then used these relative risks, in conjunction with US prevalence data on BMI, to yield estimations of excess deaths due to weight … or, for the Overweight category, lives saved.

^{Annual excess death estimates by cohort, paneled by BMI category. Image courtesy of JAMA.}

If that last line about ‘lives saved’ for being overweight chaffed you: it chaffed me, too, so let’s dig deeper. While I am not a statistician, I did read their Methods thoroughly, but still do not quite understand how they reached their estimates for excess death, which incorporate the relative risks. One seemingly important point about the relative risks for the Overweight group (above table) is that, while each estimate fell below 1, the 95% confidence intervals for every Overweight RR overlapped 1. Because a relative risk of 1 never fell outside of their confidence band for an alpha of .05 for any age group, how could they reach the conclusion that there is always a negative number of excess deaths (positive number of lives saved), “–86 094 deaths; 95% CI, –161 223 to –10 966″¹? They say that the uncertainty of the relative risk is propagated in the excess death estimate, but as I just outlined, the result does not seem coherent.

Their findings are, nonetheless, suggestive that having an ‘Overweight’ BMI may confer additional years of life, although “bias may also result from failure to control for unknown confounders that are associated with body weight and mortality,”¹ as the authors indicate. I should mention that nowhere in the paper do the authors esteem their finding of a decreased relative risk for ‘overweight’ BMIs. In a way, they elegantly dismiss that peculiar result, stating simply that “Overweight was not associated with excess mortality.”¹

In any case, the more important fact to glean from this discussion is that any large deviation from a normal BMI is associated with increased mortality. In response to the Flagel study, Thomas Hoerher, PhD wrote, “although mortality is an important measure of the burden of a disease, it is not the only one. Obesity also has significant impacts on morbidity, health care costs, and quality of life.”² Obesity is not healthy, and 112,000 excess death per year is a serious matter.

Footnotes/Further Reading:
(1) Excess Deaths Associated With Underweight, Overweight, and Obesity. JAMA. 2005.
(2) Controversies in Obesity Mortality: A Tale of Two Studies. RTI-UNC Center of Excellence in Health Promotion Economics. 2006.
(3) CDC Downscales Mortality Risk From Obesity, USA. MedicalNewsToday.com. 2005.

The situation: you are by yourself, and you begin to have severe chest pain, followed by acute vertigo. You are having a heart attack, and moments later you feel like you are about to faint. With a few seconds left before you lose consciousness, what do you do?

In truth, you should dial 911 on your cell phone. But after that… cough, deeply and forecefully, about once every 1 to 3 seconds. Long derailed as a hype product of the devious “world-wide web,” improvised ‘cough CPR’ may actually have some merit, according to some cardiovascular researchers. The idea of coughing to sustain arterial pressure and to induce blood flow first appeared in the Journal of the American Medical Association in 1976¹. Therein, the authors purported that coughing during ventricular fibrillation not only kept several patients conscious for up to 39 seconds after the onset of VF, but that coughing maintained arterial pressure at almost 140mmHg, compared to only 60mmHg for traditional chest compressions. That is, they indicated that ‘cough-CPR’ could have advantages over normal CPR.

And while the American Heart Association, formally and adamantly, does not endorse the maneuver², scientists continue to demonstrate that coughing during a heart attack can actually help blood circulate. The picture below shows the EKG … (Read the rest of this article »)

After spending a day fasting this past weekend, I’m interested in learning more about the idea of a ‘calorie-restricted’ diet. Basically, the idea is that by cutting back the amount of calories one ingests — say, by reducing by 1/3 — while remaining nutritionally nourished, the organism will optimize bodily resources, which can lead to a longer, healthier life.

Sound too good to be true? … it probably is. Although, from the little that I’ve read, this concept has been tested in several organisms, among which are the housefly drosophila, yeast, and, most promisingly, primates. With the exception of the housefly, studies have demonstrated that the organisms tend to lead healthier, and thus longer, lives, which makes a very appealing case. Biologically, it is reasonable to think that … (Read the rest of this article »)