Arya M. Sharma, MD

Continuing my posts on the recent articles on obesity and mental health published in the January issue of the Canadian Journal of Psychiatry, I now turn my attention to a paper by Valerie Taylor and colleagues on the many links between mental health issues and obesity.

Whilst in the previous post I have focussed on the relationship between psychiatric medications and weight gain, a problem that is common knowledge to the mental health community, this article highlights many of the lesser known links between mental health problems and excess weight. These include interesting neurobiological, psychological, and sociological factors, that are now increasingly understood.

For e.g.

“‘Atypical’ depression, a type of major depressive disorder characterized by an increase in the need for sleep and food, may actually characterize the most ‘typical’ presentation of major depression For the majority of people with depression, therefore, a diagnosis of major depression is synonymous with a phenotype that increases vulnerability towards weight problems.”

In fact,

“The neurobiology of depression [also] confers increased risk of obesity. The most common biological perturbation associated with depression is an increase in cortisol. This increase, and the hypothalamic pituitary adrenal axis abnormalities that accompany it, is similar to changes seen in Cushing syndrome, an endocrinological illness caused by an increase in cortisol that is characterized phenotypically by excessive visceral weight gain. While levels of cortisol found in major depression disorders are much lower than that of Cushings, the biological impact of excess cortisol is similar; a predisposition towards increased deposition of centrally located adipose tissue.”

In addition mood disorders often affect sleeping behaviour, which in turn affects important regulators of appetite and metabolism like ghrelin, leptin, adiponectin, and other hormones. Moreover, chronic inflammation may play a role in both major depression and obesity.

In the case of schizophrenia, primary negative symptoms like amotivation, which can be observed even in the earliest stages of the illness, may lead to reduced physical capacity and altered self-perception. Hypodopaminergic activity may in part explain increased propensity for substance use, especially cannabis, which can promote hyperphagia.

There is an increasingly recognized association between obesity and attention deficit disorder, and it may well be that impulsivity may play an important role in overeating.

Also,

“Poor planning and an inability to delay reward, processes largely mediated by the pre-frontal cortex, may lead individuals with ADHD to over-consume highly palatable, fattening foods. A related hypothesis is that individuals with low intrinsic dopamine activity in brain areas mediating reward may attempt to compensate by using various reinforcing behaviors including increased food consumption. This has been termed the “reward deficiency syndrome” and has been described separately in ADHD and in obesity suggesting that ADHD and obesity may thus reflect different manifestations of a single biological change related to low dopamine activity in prefrontal attentional areas and brain reward pathways.”

The paper also discussed findings showing that ADHD is associated with more media consumption, less participation in physical activity and organized sports.

Finally, the paper examines the literature on the relationship between obesity and childhood adverse events like sexual, mental, physical abuse and emotional neglect, which can have important impacts on the hypothalamic-pituitary-adrenal axis as well as on sex hormones that may promote fat accumulation.

“The use of food as a coping strategy or a “self-soothing behavior” is seen in both trauma patients and in those with mood disorders, and it may be related to the use of food to modulate neurotransmitters involved in affect control. Most work in this area has focused on serotonin and dopamine, both of which play a critical role in both eating behavior and mood regulation. It may be that the ability of certain foods to temporarily boost mood can create a behavioral cycle where food is consumed to control feelings of sadness.”

As readers of these posts may be well aware,

“The relationship between trauma and weight is especially evident during weight loss treatment programs and in bariatric surgery programs, a past history of trauma can be a harbinger of post-operative problems. Food and weight gain in response to abuse may be related to a desire to become “bigger” to be able to defend against an abuser, it may have been a way to change appearance when an individual inaccurately felt they were somehow provoking the abuse or it may have become a surrogate comfort mechanism when appropriate supports failed.”

Thus, clinicians (and patients) must be aware of the complex relationship between obesity and mental health issues that go well beyond just the issue of weight gain with psychiatric medications (which of course further compound these issues).

All the more reason, why all health professionals called upon to manage obesity should be well versed in recognizing and helping patients address mental health problems.

AMS
Edmonton, Alberta

Yesterday, on the first day of the 1st Caribbean Obesity Forum, I presented various talks on obesity - its economic implications, its assessment and the need for firmly anchoring obesity treatment in primary care.

Interestingly, several family doctors in the audience raised the interesting issue that here on Barbados (as probably on other islands) many patients are actually quite happy with their weights.

One family physician noted in his presentation the case of an overweight woman, who presented in his practice with diabetes. A few weeks after starting her on metformin, she came back considerably distressed about the fact, that she had now lost a few kilos. He noted that despite explaining out that her diabetes was now under control and her blood pressure had improved, she remained unconvinced about the benefits of being on this treatment. To her, losing weight equated directly with being unhealthy and ‘less sexy’ to her husband.

This topic came up several times during the day, where the issue of how to address obesity related health problems in a culture, where excess weight is considered both physically attractive and a sign of good health - never mind that the Caribbean (as pointed out by other speakers) now has some of the highest diabetes rates in world - I have heard Jamaica referred to as the world capital of foot amputations.

The notion of obesity as a sign of good health of course is not that surprising - especially in countries where malnutrition, infectious diseases, gut parasites, and other ‘wasting’ conditions, are endemic. Being skinny is a sure sign of sickness and weight loss is most alarming.

One discussant reminded me of the African practice of fattening rooms, where brides-to-be would be sequestered and overfed in order to be their ‘best weight’ on their wedding day - the exact opposite of Western societies, where brides wanting to lose weight provide healthy profits for the weight-loss industry.

Obviously, in such a setting, the very idea that excess weight may adversely affect pregnancy outcomes, is clearly a hard sell - as noted by the colleague speaking on the issue of epigenetic programming in utero.

In the discussions, I did point out that while we certainly did not have an issue with women not wanting to lose weight (in fact our challenge is perhaps the opposite - convincing many women that the few extra pounds they would so desperately like to shave off their butts and thighs may actually protect them from diabetes and other health problems), we do have a problem with men trivialising or denying the problem.

These learnings are nevertheless important to me, especially when practicing in a country like Canada, where we see patients with a wide range of ethnic and cultural backgrounds.

As clinicians, let us be aware that when some of our patients appear unconcerned about their weight-realated health problems, they may not simply be unmotivated to consider obesity treatments - they (and their family and friends) may actively oppose and resist them.

AMS
Bridgetown, Barbados

I often joke that the easiest way to gain 25 lbs is to lose 20!

Unfortunately, this may not be much of a joke, as there is mounting evidence that intentional weight loss may indeed be an important driver of long-term weigh gain.

New evidence in support of this hypothesis comes from a Finnish twin study by Kirsi Pietiläinen and colleagues from the University of Helsinki, published in the latest issue of the International Journal of Obesity.

Subjects included 4129 individual twins from the population-based FinnTwin16 study (90% of twins born in Finland 1975–1979). Weight and height were obtained from longitudinal surveys at 16, 17, 18 and 25 years and examined in relationship to the number of lifetime intentional weight loss (IWL) episodes of more than 5 kg at 25 years.

A single IWL episode increased the risk of becoming overweight by age 25 almost three-fold in women and two-fold in men. In fact, women who reported two or more IWL episodes had an even higher (5-fold increased) risk of becoming overweight at age 25.

In monozygous twin pairs discordant for IWL, co-twins with at least one IWL were 0.4 BMI units heavier at 25 years than their non-dieting co-twins despite no differences in baseline BMI levels.

Similarly, in dizygous pairs, co-twins with IWLs gained progressively more weight than non-dieting co-twins (BMI difference 1.7 units at 16 years and 2.2 units at 25 years).

These findings not only confirm previous studies that dieters may be more prone to future weight gain but also provide evidence that, this obesogenic effect of dieting is apparently independent of genetic factors.

All the more reason to warn against the widespread obsession with ‘cosmetic’ weight loss - as I have said before, all weight loss attempts should be medically indicated and anyone attempting to lose weight needs to be warned that they may in fact be increasing their long term risk of becoming (even more) overweight or obese.

On the other hand, in cases where weight loss is indeed medically indicated, considerable effort and long-term follow up will be required to prevent relapse - not only is weight loss not a ‘cure’ for obesity but, in many cases, losing weight can actually make the problem worse!

Imagine if all diet and weight loss products and programs had to come with a  clear ‘warning’ that use of these products or programs may increase the risk of obesity!

Clearly something for the weight-loss industry and the many self-appointed weight-loss ‘gurus’ to chew on.

AMS
Edmonton, Alberta

Regular readers of these pages will be well aware of the many studies that now show a close association between less sleep and weight gain.

In fact, a now often shown slide clearly documents, how steadily decreasing hours of sleep remarkably parallels the steady increase in obesity rates over the past decades.

In addition, substantial data from animal experiments clearly documents how sleep deprivation has profound obesogenic effects on appetite and metabolism.

So does getting more sleep protect against obesity or even help with weight loss?

This question was now addressed by Jean-Phillipe Chaput (CON Bootcamper) and colleagues at the University of Ottawa in a paper just published in the International Journal of Obesity.

The researchers analysed data from a 6-year longitudinal, observational study in adults aged 18-64 years.

Short-duration sleepers (<6 h per day; n=43) at baseline were divided into two groups: (i) those who increased their sleep duration to a ‘healthy’ length of 7-8 h per day at year 6 (mean increase: 1.52 h per day; n=23); and (ii) those who maintained their short sleep duration habits (mean change: -0.11 h per day; n=20).

While both groups had similar baseline characteristics, short-duration sleepers who maintained their short sleep duration experienced a greater increase in body mass index (BMI) (difference: 1.1) and fat mass (difference: 2.4 kg) over the 6-year follow-up period than short-duration sleepers who increased their sleep duration, even after adjustment for relevant covariates.

In contrast, there was no significant difference in adiposity measures between short-duration sleepers who increased their sleep duration and a control group of individuals who reported sleeping 7-8 h per day at both baseline and year 6 (n=173).

As the authors point out, this is the first longitudinal data suggesting that increasing sleep duration in individuals with short sleep duration is associated with a reduced risk of weight gain.

Clearly, it would perhaps now be time for a controlled trial of sleep intervention in short-sleepers with weight problems.

While it is unlikely that simply getting more sleep will lead to weight loss - remember, prevention of weight gain is the first sign of success.

I wonder if my readers notice any relationship between lack of sleep and their own propensity for weight gain.

AMS
Edmonton, Alberta

Chaput JP, Després JP, Bouchard C, & Tremblay A (2011). Longer sleep duration associates with lower adiposity gain in adult short sleepers. International journal of obesity (2005) PMID: 21654631

Gestational diabetes and excessive gestational weight gain have significant implications for the health of both mother and child.

Anne-Sophie Morisset and colleagues from Laval University, Quebec City, Canada, now examined the relationship between weight gain early in pregnancy and the risk for gestational diabetes, in a paper just published in the Journal of Womens Health.

The researchers examined data from medical records of women who delivered between January and December 2007 at the Laval University Medical Centre, which included 294 women (55 cases of gestational diabetes and 239 controls).

Weight gain in the first trimester was significantly higher in patients who developed gestational diabetes than in controls (3.4 vs. 1.9  kg), whereas whereas weight gain in the third trimester was significantly lower in diabetes patients compared to controls (4.1 vs. 6.3 kg).

Both prepregnancy BMI and first trimester weight gain were significant and independent predictors of diabetes suggesting that both preconception weight as well as weight gain during the first trimester may warrant greater clinical attention.

This is particularly important given the discussions and concerns about the fetal development theory of epigenetic program, which many today believe to be one of the key drivers of childhood obesity.

AMS
Edmonton, Alberta

Morisset AS, Tchernof A, Dubé MC, Veillette J, Weisnagel SJ, & Robitaille J (2011). Weight Gain Measures in Women with Gestational Diabetes Mellitus. Journal of women’s health (2002) PMID: 21332414