Review of Academic Journal Series

Lancet. 2006 Aug 19;368(9536):666-78.

Association of bodyweight with total mortality and with cardiovascular events in coronary artery disease: a systematic review of cohort studies.

Romero-Corral A, Montori VM, Somers VK, Korinek J, Thomas RJ, Allison TG, Mookadam F, Lopez-Jimenez F.

Division of Cardiovascular Diseases, Mayo Clinic College of Medicine, Mayo Foundation, Rochester, MN 55905, USA.

These authors took 40 studies, with a total of 250,152 patients followed an average of approximately 3.8 years.  They specifically looked at the estimated risks of coronary artery disease (CAD) to see if there were associations between obesity, total mortality and cardiovascular events.  They were able to classify the risk estimates across five bodyweight groups: low, normal (used as the reference bodyweight group), overweight, obese and severely obese. 

What they found, across over 250,000 people is that patients with the lowest body mass index (BMI) (below 20) had an increased relative risk for total mortality (dying for other reasons) and cardiovascular mortality.  OF NOTE, patients classified as overweight (BMI 25-29.9) has the lowest risk for total mortality and cardiovascular mortality, COMPARED to those people with a normal BMI!  Furthermore, the authors reported that obese patients (BMI 30-35) had no increased risk for total mortality or cardiovascular mortality, and the severely obese group (a BMI over 35) did not have any increase in total mortality, but they did show increased risk of cardiovascular mortality.

Even these authors acknowledge the inconsistencies with other reported results in the field of obesity-related research, and question the efficacy of using BMI as an indicator of health.  Specifically, they suggest that using BMI makes it difficult to differential between body fat and lean mass, which would give researchers a better indication of overall health, and estimated risks of mortality.

What does this mean for us?  Take caution when reading reports that “overweight” or “obese” individuals are at higher risk for cardiovascular disease.  Because of the recent trend for researchers to use the archaic BMI standard, instead of more precise calculations of body fat and lean body mass, more and more Americans are being classed as overweight/obese – and the research does NOT support the classifications.

Are you overweight?  Do you need to lose weight? There are options to help you and you don’t have be alone with it.  BUT make the choice yourself.