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Overweight and obesity - sorting out the confusion
(June 2005)

The studies on overweight and obesity leave your head spinning. In this issue, we review, not very favorably, a New England Journal of Medicine report that says the overweight-obesity epidemic in the United States is so severe, it will stop the increase in life span that has been very steady in the United States for over 100 years, very possibly start an actual decline in life expectancy, and potentially save Social Security (presumably because lots of those fat people will die before age 65). Then, there are the conflicting figures from our prestigious Centers for Disease Control. The first alarmist figures indicated over 400,000 deaths were due to overweight and obesity each year. That was revised a few months later to 365,000 a year. Now, a really good analysis, primarily from the Centers for Disease Control, says that overweight (but not obesity) actually saves lives and the overall increased deaths from obesity is a paltry 25,814 a year. So, it's now a net death increase of about 26,000 compared to previous figures from the same august institution about 15 times that figure.

What does all this mean? How can we reconcile the startlingly different figures and conclusions? Who is right? What should the public do? In the first place, it all makes Healthful Life look good. We have consistently, for the last 15 years, said that the alarmist data were exaggerations and that they had not carefully adjusted for the overweight and obese people who control their major risk factors for heart attack and stroke (high blood pressure, high cholesterol level). We argued that, if that was done, then the risk from overweight and obesity itself is much, much smaller. We also noted the evidence for the dangers of overweight (body mass index 25 to 29.9) is not persuasive and that, for those over 65, there is no adequately documented risk even for mild obesity (Body Mass Index 30 or 31). Body mass index (BMI) is the weight in kilograms divided by the square of the height in meters; 20 to 24.9 is considered normal. But, heavily muscled or heavy boned people may have BMI values in the overweight or mild obesity levels and not really be overweight or obese.

We have argued that the increased risk from heart disease, stroke, and cancer is primarily seen in those who are at least 40 percent overweight (BMI 35 and over) who are moderately to severely obese.

The article in the Journal of the American Medical Association , April 20, 2005 is very solid, but will be debated for a long time. They looked only at the totality of all causes of death. For those who were very underweight (BMI less than 18.5), the likelihood of death was increased by 38 to 130 percent in different age groups and this was statistically significant in the 60 to 69 and over age 70 groups. For those overweight, but not obese (BMI 25 to 29.9), there was a 5 to 17 percent reduced risk of death that was not statistically significant in any age group. For those mildly obese (BMI 30 to 34.9), the risk of death was increased by 20 percent in ages 25 to 59, by 13 percent in ages 60 to 69 (neither statistically significant) and not at all over age 70. For people with at least moderate obesity (BMI 35 and above), those 25 to 59 and 60 to 69 years old had a statistically significant 83% and 63% increased risk of death, but those over age 70, even if moderately obese, had only a small and statistically insignificant increased risk.

The authors arrived at their 26,000 figure by adding the 82,000 projected increased deaths in the moderately or severely obese to the 30,000 estimated increased deaths in the mildly obese (ages 25 to 69) and then subtracting the 86,000 fewer deaths in the overweight group (BMI 25 to 29.9).

I do not think they should do that. The important figure is 82,000 extra deaths from moderate to severe obesity.

To me, the data should be interpreted as follows:

1.Overweight (as contrasted to obesity) does not increase overall death rates. Whether it actually offers very mild protection against death is unclear.

2.Mild obesity (BMI 30 to 34.9) certainly increases the risk of diabetes and may increase the risk of death to a very small extent in those ages 25 to 69, but not those over age 70.

3.Moderate to severe obesity is a real health problem increasing the risk of and death from diabetes, heart attack, stroke, and some cancers.

Remember, this study looked at death rates, not at specific causes of death and not at non-fatal consequences of overweight, mild obesity, and, particularly, moderate to severe obesity. Those would include non-fatal heart attacks, non-fatal strokes, gout, arthritis, diabetes. Until we have those data, studied by the same analytical techniques, we do not have the full story. However, there are other data that provide a lot of valuable information. A study of almost 20,000 Finnish men and women published in 2004 showed that obesity was related much more to disability and chronic illness than to deaths; they had a big increase in unhealthy years of life.

Overweight and mild obesity do result in greater risk factors for heart disease and stroke - an increase in blood cholesterol levels and in blood pressure, as well as an increase in blood glucose (sugar levels).

Should people be concerned about overweight or mild obesity? The answer is yes, but they should put it in perspective.

1.If you are overweight or mildly obese, you may feel sluggish and not like your appearance. Shedding a few pounds may improve your vigor, appearance, and attitude.

2.If you are overweight or mildly obese, it is easy to slip into moderate obesity - and that spells trouble.

3.Overweight and obesity are tied to the diabetes epidemic; 80 percent of adult onset diabetics are overweight or obese and the evidence is clear that weight reduction (often quite modest) and increased physical activity can prevent most of the diabetes.

4.It is imperative if you are overweight or obese to check your risk factors - blood pressure, cholesterol level, high-density lipoprotein cholesterol (HDL, good cholesterol) and low-density lipoprotein cholesterol (LDL, bad cholesterol) levels and do something about them by diet, exercise, and, if necessary, medications.

So, this is a marvelous article in the sense that it reverses the exaggeration and puts overweight and mild obesity in perspective. Hopefully, it will stop some assisted living places and nursing homes for people over age 70 from putting their clients/patients on rigid diets because of overweight or obesity, forgetting that, for many of their clients/patients, eating is the most enjoyable part of their age-restricted lives. But, overweight and mild obesity do contribute to some diseases, can cause disability and frailty in some, and can reduce the quality of life; and moderate to severe obesity makes the situation worse, causes some diseases, and increases death rates. So, all in all, normal weight is better than overweight or mild obesity, and much, much better than moderate to severe obesity.

Flegal, K.M., et al. Excess deaths, associated with underweight, overweight, and obesity. Journal of the American Medical Association, Vol 292 (April 20) Pgs 1861-1867. 2005.

Visscher, T.L.S, et al. Obesity and unhealthy life-years in adult Finns.  Archives of Internal Medicine. Vol 164. Pgs 1413-1428. 2004.