For a number of reasons, I’m not a fan of the BMI. But my argument hasn’t been that a higher BMI is a neutral or positive measure; it’s that the BMI is really fuzzy math and adds little value compared to height and weight (which is what the BMI is after all — a measure of height and weight). But I get that researchers like it as a shorthand for studying overweight and obesity.
Over the last week, a couple of studies have been published highlighting higher mortality risk with a higher BMI. The first study showed that people with a higher BMI had a higher risk of mortality even if they didn’t show the traditional risk factors associated with metabolic syndrome.
The second study shows that women with a higher BMI have a poorer prognosis and higher risk of death due to breast cancer.
Yesterday, Peter at Obesity Panacea posted an interview with one of the researchers from the first study. The entire interview is well worth a read, but this particularly caught my attention in light of what I’d read in the second study.
From the breast cancer study (emphasis mine):
After 30 years of follow-up (from 1977 through 2006), the researchers found that women with higher BMIs were older and had more advanced disease at diagnosis compared with those who had a BMI within the normal range. The risk of distant metastases increased the higher the BMI.
From Obesity Panacea (emphasis mine):
[In] our study, 80% of the deaths in the metabolically-healthy obese were due to cancer and ‘other’ causes. Other causes are likely traumatic injuries, which highlights an important point. Obese individuals are less likely to survive a trauma as compared to normal weight individuals despite similar injuries. This is related to longer transport times due to their higher body weight, and difficulty assessing and treating the injuries due to their increased size. Further, they are less likely to see their physicians regularly, which may be in part why cancer is generally diagnosed in obese individuals at later stages.
In other words, both of these recent studies imply that some of the mortality risk from BMI may be due to people getting treatment later in their disease. This suggests that people are avoiding getting treatment and/or their doctors not screening them early enough.
In Stigma and Discrimination in Weight Management and Obesity, Brownell and Puhl report (emphasis mine; see original for cites):
Negative attitudes in physicians may lead obese persons to avoid seeking health care. In one study, 290 women and more than 1300 physicians anonymously responded to questionnaires about the influence of obesity on the frequency of pelvic examination. Among women, reluctance to undergo pelvic exams increased with weight, and very overweight women were significantly less likely to report receiving annual pelvic exams.
Among physicians, 17% reported reluctance to provide pelvic exams to very obese women, and 83% indicated reluctance to provide a pelvic exam if the patient herself was hesitant. Given that overweight women may hesitate to obtain exams and that physicians are reluctant to perform exams on obese or reluctant women, many overweight women may not receive necessary preventive care.
Two other studies also documented delays in seeking medical care by obese women. One study found a significant relation between body mass index (BMI) and appointment cancellation. More than 12% of women indicated they delayed or canceled physician appointments because of weight concerns. In addition, 32% of women with BMI over 27 and 55% of women with BMI over 35 delayed or canceled visits because they knew they would be weighed. The most common reason for delaying appointments was embarrassment about weight.
Wow. This concept of stigma and discrimination isn’t new news, but to see it reflected in these recent studies is disturbing on a number of levels. Mostly because both obesity and stigma/discrimination are wicked problems. Neither has an obvious or easy solution.
Update, 1/21. CNN has more: The surprising reason why being overweight isn’t healthy.