As one author put it:
Though commonly considered a state of “overnutrition”, obesity has increasingly been recognized as a risk factor for several nutrient deficiencies, including lower levels of antioxidants and certain fat-soluble vitamins.Ironically, this fact went undiscovered until fat people who had had a gastric bypass started having severe nutritional deficits afterwards. To further track the problem (and to try to blame something other than the surgery for these deficits), bariatric surgeons began documenting the nutritional status of weight loss surgery (WLS) candidates before the surgery.
What they discovered was that many people of size actually have significant nutrient deficits, even before surgery.
Let's be clear ─ the surgery indeed does make these deficits far worse, but many are not starting on an equal playing field before surgery even has an effect.
The $64,000 question is WHY many people of size have nutritional deficits.
There are three main possibilities bandied about in the research to explain these deficits:
- Nutrutional deficits are caused by years of junk food, unbalanced intake, and not enough fruits and vegetables
- Nutritional deficits are the cumulative effect of years of dieting and limited intake common among many fat people
- Nutritional deficits more common in people of size because they may not absorb nutrients as efficiently as others
Of course, the weight loss surgery studies usually blame junk food and a poor diet for the nutritional deficits among "obese" people. Here's what one author (Xanthakos 2009) wrote about it:
The presence of nutritional deficiencies in overweight and obesity may seem paradoxical in light of excess caloric intake, but several micronutrient deficiencies appear to be higher in prevalence in overweight and obese adults and children. Causes are multifactorial and include decreased consumption of fruits and vegetables, increased intake of high-calorie, but nutritionally poor-quality foods, and increased adiposity, which may influence the storage and availability of some nutrients.Weight loss surgeons like this Too-Much-Junk-Food explanation because it gives them an easy out by blaming the victim for the problem.
And certainly there could be some truth to this possibility for some fat people.....some fat folk really do have poor nutrition, are binge eaters, and/or mostly eat junk/highly processed food, and that could certainly depress their nutritional reserves.
However, this explanation is simply too facile and convenient. Yes, some fat people have terrible habits and this can have effects on their nutritional reserves ─ but some have normal habits and yet still have nutritional deficits.
I hope the researchers look further than these "easy out" conclusions. They need to dig a little deeper with the research and stop making assumptions about how "all fat people" eat and live.
Years of Dieting?
The second possibility ─ nutritional deficits are caused by years of dieting and limited calories ─ certainly seems logical. Even the healthiest "lifestyle change" diets have difficulty providing sufficient amounts of nutrients if the caloric intake drops too far. Given that many fat folk have been on 1200 calorie (and less) diets, are our bodies able to extract enough nutrients from that amount of calories?
And what about those of us who have been on Very Low Calorie Diets (VLCDs); how much does that steal from our nutrient stores?
[Most of my dieting years were spent on moderate, "healthy" diets, usually 1200-1500 calories, with balanced intake of all the nutrient groups. However, my last big dieting attempt involved a medically-supervised VLCD of about 500 calories per day. I spent six months on that stupid VLCD; what do you think that did to my nutrient stores?]
Inadequate Nutrient Absorption?
To me the most intriguing possibility is that perhaps fat people simply do not absorb nutrients from their food as efficiently as others. Unfortunately, this is the possibility with the least amount of research, just tantalizing mentions of this possibility in studies that I've read, but without providing documentation or proof that this does indeed occur.
Certainly it is thought by some doctors that adipose stores can sequester fat-soluble vitamins (like vitamin D) and that this is why fat people tend to have very low Vitamin D levels.
But I've also seen some passing references in research of the possibility that fat people's gut and/or intestinal flora do not absorb certain nutrients (like folate) properly. Some have speculated that this may be why we have lower levels of folate (and thus more birth defects) than thinner people, despite research showing no difference in folate intakes between groups.
I think this is an incredibly intriguing thought, and one that intuitively seems quite possible to me. Now we just need research to actually really examine this question thoroughly, instead of making passing referece to the possibility without really documenting what study has been done on it.
It is clear that many "obese" people, rather than being overnourished, are actually undernourished instead. They often have nutrient deficits of varying degrees of severity.
Nobody quite knows why this is; there is lots of speculation in the research about it, with many assumptions about how fat people "must" be eating (with little actual proof of these assumptions). It may be bad habits, it may be deficits from years of dieting, or it may be decreased ability to absorb nutrients from food. Perhaps it is a synergistic combination of some or all of these ─ or perhaps it is something else entirely.
What's needed is further study ─ study not just documenting the existence of nutrient deficits, but seeking the causes of these deficits, without making assumptions along the way.
Compare the "obese" people with significant nutrient deficits to those without significant nutrient deficits, for example, and see if that comes up with any meaningful clues about nutrient intake, hormonal interference, or other issues. Or compare the efficacy of nutrient absorption in the guts of average-sized people and the guts of "obese" people and see if there are any differences.
There are many ways to start investigating this finding further; it's time to create some more meaningful research on the topic, research that might actually lead to some breakthroughs in fixing the problem.
The ironic and maddening thing to me is that the undernourished status of so many fat people would have gone largely undiscovered had it not been for weight loss surgery (WLS). This is important knowledge to have, but how terrible that it comes at such a price.
Not that I hate people who have had WLS or anything; it's their body and they get to choose what they do with it. If they make an educated choice for it, who am I to begrudge them that? I understand what drives them to that choice; I have several dear friends who have had WLS, and while I don't agree with all their reasons, I wish them well.
But my gripe with research and publicity about WLS is that its long-term benefits are being oversold by selective reporting, complications are being hidden and minimized, and long-term risks are really greatly underemphasized.
There are a lot of people out there who are sick from side effects of WLS, and that story is conveniently not making the news. Only the stories of people in the "honeymoon" period of the first few years after WLS are being reported, not the nightmare stories of those who develop long-term problems from the procedure. That's not fair and balanced reporting.
And how frustrating it is that doctors only start to notice and care about the nourishment status of very fat people in order to explain away the complications associated with their risky weight-loss interventions.
Why was this undernourishment only discovered when doctors were trying to explain away the severity of nutrient deficits in fat people who had had WLS? Why didn't doctors notice, test for, or care about these nutrient deficits in fat people before? Why was it only important when it affected their bottom line?
In addition, it's important to remind health professionals that nutrient deficits in people who have had WLS are made far worse by the surgeries, even among many who are fully "compliant" with their vitamins. The fact that many have nutrient deficits before the surgery certainly adds to the problem, but surgeries that worsen their intestinal tracts' abilities to absorb nutrients definitely worsen the problem to levels far beyond what it was in the first place. Don't blame it all on pre-surgery status or lack of vitamin compliance; the surgery definitely is part of the problem.
It's time for doctors and researchers to stop stereotyping and blaming, and it's time for them to start examining WHY people of size tend to have higher rates of nutrient deficits, what causes these deficits, and how they can be treated effectively.
Aasheim ET, Hofsø D, Hjelmesaeth J, Birkeland KI, Bøhmer T. Vitamin status in morbidly obese patients: a cross-sectional study. Am J Clin Nutr. 2008 Feb;87(2):362-9. PMID: 18258626
Study from Norway that prospectively examined 110 consecutive "morbidly obese" patients and 58 healthy controls not taking multivitamin supplements. The fat patients had "significantly lower concentrations of vitamin B-6, vitamin C, 25-hydroxyvitamin D, and lipid-standardized vitamin E than did the healthy controls...The status of these vitamins was inadequate in a substantial proportion of the patients (11-38%)."Carlin AM, Rao DS, Meslemani AM, Genaw JA, Parikh NJ, Levy S, Bhan A, Talpos GB. Prevalence of vitamin D depletion among morbidly obese patients seeking gastric bypass surgery. Surg Obes Relat Dis. 2006 Mar-Apr;2(2):98-103. PMID: 16925330
Prospectively studied vitamin D levels before surgery in 279 "morbidly obese" patients in Michigan seeking gastric bypass surgery. Vitamin D depletion, defined as serum 25-hydroxyvitamin D level less than or= 20 ng/mL, was found in 166 patients (60%)...Vitamin D depletion was significantly more prevalent in the African-American patients than in the white patients (91% vs 48%; P less than .001)...Before gastric bypass surgery, a majority of morbidly obese patients have vitamin D depletion and secondary hyperparathyroidism. Studies evaluating the effects of gastric bypass on vitamin D metabolism must consider preoperative vitamin D nutritional status.Xanthakos SA. Nutritional deficiencies in obesity and after bariatric surgery. Pediatr Clin North Am. 2009 Oct;56(5):1105-21. PMID: 19931066
"The presence of nutritional deficiencies in overweight and obesity may seem paradoxical in light of excess caloric intake, but several micronutrient deficiencies appear to be higher in prevalence in overweight and obese adults and children. Causes are multifactorial and include decreased consumption of fruits and vegetables, increased intake of high-calorie, but nutritionally poor-quality foods, and increased adiposity, which may influence the storage and availability of some nutrients. As the obesity epidemic continues unabated and the popularity of bariatric surgery rises for severely obese adults and adolescents, medical practitioners must be aware of pre-existing nutritional deficiencies in overweight and obese patients and appropriately recognize and treat common and rare nutritional deficiencies that may arise or worsen following bariatric surgery. This article reviews current knowledge of nutritional deficits in obese and overweight individuals and those that commonly present after bariatric surgery and summarizes current recommendations for screening and supplementation."Ammor N, Berthoud L, Gerber A, Giusti V. [Nutritional deficiencies in candidates for bariatric surgery] Rev Med Suisse. 2009 Mar 25;5(196):676-9. PMID: 19462611
[Article in French]
"98% of patients who have undergone a gastric bypass for treating severe obesity develop multiple micronutrient deficits. However, prior to surgery, it isn't rare to find nutrient deficiencies. Indeed, the dietary intakes of surgery candidates are often unbalanced, lacking in variety especially in high vitamin and mineral nutrients. We present the preliminary results concerning the qualitative and quantitative analysis in a group of patients waiting for a gastric bypass. The recommended daily amounts in vitamin B9, vitamin D and iron are insufficient in the majority of the patients. The correction of nutritional intakes is advisable, even before the surgery, in order to reduce the risks of developing biological deficiencies."Kaidar-Person O, Rosenthal RJ. Malnutrition in morbidly obese patients: fact or fiction? Minerva Chir. 2009 Jun;64(3):297-302. PMID: 19536055
"Reports of nutritional deficiencies after Bariatric surgery have lead investigators to inquire about the preoperative nutritional status of morbidly obese patients. Interestingly, numerous reports demonstrated a pattern of low levels of various micronutrients among overweight and obese patients, even in comparison with normal weight population. In this article we reviewed the literature for micronutrient deficiencies in obese patients prior to weight reduction surgery."Kaidar-Person O, Person B, Szomstein S, Rosenthal RJ. Nutritional deficiencies in morbidly obese patients: a new form of malnutrition? Part A: vitamins. Obes Surg. 2008 Jul;18(7):870-6. PMID: 18465178 See also: Kaidar-Person O, Person B, Szomstein S, Rosenthal RJ. Nutritional deficiencies in morbidly obese patients: a new form of malnutrition? Part B: minerals. Obes Surg. 2008 Aug;18(8):1028-34. PMID: 18461424
"It is a common belief that clinical vitamin or mineral deficiencies are rare in Western countries because of the low cost and unlimited diversity of food supply. However, many people consume food that is either unhealthy or of poor nutritional value that lacks proteins, vitamins, minerals, and fiber. In this, article we reviewed the literature and highlighted the vitamin deficiencies in obese patients before bariatric surgery. Deficiency of dietary minerals is described in the accompanying manuscript. The prevalence of vitamin deficiencies in the morbidly obese population prior to bariatric surgery is higher and more significant than previously believed."Schweiger C, Weiss R, Berry E, Keidar A. Nutritional deficiencies in bariatric surgery candidates. Obes Surg. 2010 Feb;20(2):193-7. PMID: 19876694
"Preoperative blood tests of 114 patients (83 women and 31 men) were collected...The prevalence of pre-operative nutritional deficiencies were: 35% for iron, 24% for folic acid, 24% for ferritin, 3.6% for vitamin B12, 2% for phosphorous, and 0.9% for calcium, Hb and MCV level was low in 19%. High levels of PTH were found among 39% of the patients...Patients with BMI greater than or = 50 kg/m(2) were at greater risk for low folic acid (OR = 14.57, 95% CI:1.4-151.34). Patients with high income were less likely to have iron deficiency (OR = 0.19, 95% CI:0.038-0.971). A high prevalence of nutritional deficiencies was found amongst bariatric surgery candidates suffering from morbid obesity."