Thursday, August 17, 2006

The Cheetos Factor

Nutritional status
&
Weight
While on the surface it would appear that these two issues are inextricably linked, that is not necessarily the case. The average person, observing a gaunt, malnourished denizen of a poor third world country would accurately assume that person's nutritional status is extremely poor, going along with his "under-healthy" weight. But what about the obese person? Once again, the average person would assume that the obese patient is, while certainly not healthy, clearly not malnourished in any meaningful way.

Actually, that is not always true --- the morbidly obese patient in the United States has a very good chance of having demonstrable deficits in nutrition. This has been shown previously, but there is a good study published in the July issue of the Journal of Gastrointestinal Surgery that really illustrates this point nicely. The study, entitled Preoperative Nutritional Status of Patients Undergoing Roux-en-Y Gastric Bypass for Morbid Obesity, comes from the Dept. of Surgery at North Shore Univ. Hospital in New York. They retrospectively reviewed a series of preoperative nutritional markers in a consecutive series of 379 patients undergoing gastric bypass surgery for morbid obesity; these were not patients that were "a little" overweight, as the average BMI for the group was 51.8 ± 10.6.
Preoperative values of serum albumin, serum calcium, 25-OH vitamin D, serum iron, ferritin, hemoglobin, vitamin B12, and thiamine (vitamin B1) were examined and the prevalence of deficiencies noted. Values for serum albumin, serum calcium, serum iron, ferritin, and hemoglobin were available for all patients. Thiamine and 25-OH vitamin D levels were available for patients undergoing surgery after July 2003 (n = 141 and n = 144, respectively). Data were also stratified based upon age, gender, and race.
From the table in the results section, here are the percentages of patients with demonstrable deficiencies in the values tested; those that reached statistical significance are highlighted:
Albumin 1.1%
Calcium 3.2%
25-OH Vitamin D 68.1%
Iron 43.9%
Ferritin 8.4%
Hemoglobin 22%
Vitamin B12 0%
Thiamine (Vitamin B1) 29%
These patients do not suffer from protein-calorie malnutrition (as exemplified by normal albumin levels), but exhibit the effects of poor dietary habits. What is particularly striking to me is the fact that a large proportion of these patients were found to have significant deficits in Vitamin D and Thiamine stores, which can compound their risk for the development of postoperative neurological complications (Thiamine) and metabolic issues (Vit. D). The predominant focus in vitamin supplementation for these patients postoperatively has been to supplement with Vitamin B12 and iron, due to the known effects of this procedure on absorption of those important nutritional components. Most programs also recommend multivitamins and extra calcium as well. Given the risk for neurologic problems associated with thiamine deficiency, it would seem prudent to ensure proper thiamine supplementation.

For many non-clinicians, the question remains -- why do these people, who appear to be more than supplemented with nutrition, have such deficits? While there are many compounding etiologies, I like to call this the end result of the Cheetos Factor. Most truly morbidly obese patients not only consume large volumes of food, a significant proportion of that intake is lacking in basic nutritional requirements. Ever look at the nutrition label on a bag of Cheetos? It makes the idea of going into the backyard and eating weeds seem a bit healthier.

We can all eat in a healthier manner, and certainly I am no stranger to the inside of a Cheetos bag. It behooves clinicians, however, to not make assumptions about the nutritional status of morbidly obese patients. Just as we are well aware of the effects of obesity in causing diabetes, sleep apnea, heart disease, DJD, etc., we need to be very cognizant of the potential for nutritional deficits in these patients who outwardly appear to have no capacity for them.