Are Smaller Families Driving the Obesity Epidemic?
Readers may be aware of the “Resource Dilution Hypothesis”, which postulates that there is a dilution of familial resources available to children in large families, and a concentration of such resources in small ones. This “dilution” effect could not only affect material factors (including food, participation in organized sports, higher education, etc.) but also emotional factors (including parents undivided attention, time, interaction, etc.). While the importance of this “dilution” effect remains hotly debated, at face value, it sounds plausible. Indeed, there is no doubt that in most Western countries (with increasing standard of living), recent decades have seen a substantial reduction in the number of offspring per family, resulting in a significant increase in first and second-borns as part of the overall population. Now, a large longitudinal study by José Derraik and colleagues, published in the Journal of Epidemiology and Community Health, reports that first-born women (in Sweden) tend to be significantly heavier (and slightly taller) than second-born women, leading the authors to suggest that decreasing family size may have something to do with the increase in obesity seen over time in that country. Indeed, based on this study involving 13,406 pairs of sisters who were either first-born or second-born (n=26 812), the first-born were about 2.4% heavier than their second-born sisters with a 30-40% greater chance of having overweight or obesity. While this difference may seem rather subtle, at a population level, over generations, such effects can well result in substantial shifts in the population BMI, as a greater proportion of people are first-born. (if every family had 5 children, 20% of kids would be a first-born, If every family has 2 children, 50% of kids would be a first-born, if every family had only 1 kid, 100% of kids would be a first-born) As interesting as this idea may seem, there are several issues with this type of analysis, which may well be confounded by all kinds of issues and can hardly prove causality. Nevertheless, a similar finding has been reported in male first-borns and the hypothesis certainly has significant face value. Paradoxically, however, although overall family sizes have decreased, people in lower socioeconomic strata, who tend to have more kids, also tend to have the highest obesity rates. The obvious explanation for this would perhaps also implicate the “resource dilution hypothesis”, as more kids means less money for food, resulting in more (cheaper) caloric-dense processed foods and greater food insecurity. Accordingly, I would predict that there may well… Read More »
Durability of Diabetes Remission After Bariatric Surgery
There is no doubt that for the vast majority of patients with type 2 diabetes, bariatric (or, as some surgeons prefer to call it, “metabolic”) surgery, can lead to marked improvement and even remission of diabetes. A paper published in The Lancet by Geltrude Mingrone and colleagues, shows that even five years following surgery, about 50% of patients who had a biliopancreatic diversion (a rather uncommon and somewhat drastic form of bariatric surgery) and about 40% of patients who had a roux-n-y gastric bypass will still be in remission. No doubt (as the study shows), such results are unthinkable with conventional treatments. Although numbers are small, the fact that 25% of the non-surgical patients in this study experienced major complications from their diabetes, compared to none in the surgical groups, suggests that this is not simply glucose cosmetics but rather, that the metabolic benefits of surgery do turn into tangible benefits. So what does this mean for the diabetes epidemic – not much, I’m afraid. Not because surgery is not effective – it surely is. Unfortunately, however, surgery is not scalable the way medical treatments are. Even if we magically saw a three-fold increase in bariatric surgery (to worldwide about 1 million surgeries a year), this would hardly make a noticeable dent in the prevalence (or for that matter complications) of over 400 million people living with diabetes. Even a five or ten-fold increase in metabolic surgery would hardly be noticeable at a global level. Bariatric surgery (as most surgeries), is simply not a scalable procedure for a disease that affects 15% or more of the population. Thus, aside from helping the lucky few, who do somehow manage to get surgery, the real lesson here is that we urgently need to understand exactly why surgery works (it is not just weight loss, although this does contribute to the benefit). There are many things that happen after surgery – changes in hormonal responses to food intake (e.g. higher levels of GLP-1), changes in gut microbiota, changes in bile acid metabolism). We need to understand these factors and find non-surgical ways to mimic these changes in a manner that allows scalability to millions of people around the world. This does not mean we need to stop doing surgery – rather, the more patients can benefit from this treatment now, the better (for them). But let us not kid ourselves that surgery will one… Read More »
Obesity Down Under
Following a rather relaxed August, which included meeting my new grand daughter and turning my attention to jazz guitar, I spent the last week in Australia speaking at the Australian Diabetes and Diabetes Educator conference in Adelaide and visiting colleagues at the Melbourne Baker Institute and Sydney University’s Charles Perkins Centre. Clearly, Australia has an obesity problem that easily rivals that of most “western” countries, with no real solutions in sight (as in most “western” countries). As virtually everywhere else, much government talk (and millions of dollars) focusses on prevention, while access to obesity management within the healthcare system (public or private) remains as sparse and unfunded as everywhere else. Whilst other countries are gradually grappling with the idea that obesity, once established, must be considered a chronic disease (and thus requires the same approach to management as any other chronic disease), it appears that government and professional agencies in Australia are particularly resistant to accepting this reality. This is especially surprising, as some of the best and strongest evidence for the chronicity of obesity and the complex biological responses that occur to defend against weight loss and virtually guarantee weight regain (including studies published in the New England Journal of Medicine and the Lancet), come from my colleague Joe Proietto’s group Down Under. I guess the fact that even the best science rarely translates into effective policies is not just a problem in Canada. @DrSharma Sydney, Australia
Why Treating Severe Obesity Has The Highest Potential For Health Cost Savings
As the latest HQCA report on obesity in Alberta released this week, the substantial population burden of overweight and obesity (now affecting 6 in 10 Albertans) is a significant driver of health care costs in the province. In the US, this increased health care cost for adult obesity is estimated at around $3,508 per individual with a BMI greater than 30 for a total of well over US$ 300 billion per year. However, as highlighted in a recent article by John Cawley and colleagues in PharmacoEconomics, health care costs are not equally distributed across all people living with increased body weight – rather, obesity related health care costs rise exponentially with increasing BMI levels (i.e. at the extremes of BMI). Thus, the greatest health care savings for individual patients can be expected in those living with severe obesity. To illustrate this, the researchers used data from the US Medical Expenditure Panel Survey from 2000-2010 (n=41,435), to calculate the potential annual savings in health care costs (in US $ in the US health care system), for various reductions in body weight in individuals with BMI levels ranging from 30 kg/m2 to 45 kg/m2. Thus, for e.g. the annual cost savings with a 5% reduction in body weight for someone with a BMI of 30 kg/m2 amounted to a mere $69 per year. This figure, however, increased exponentially for people with higher BMIs, increasing to $528, $2,137, and $10,030 in an individual with a BMI of 35, 40, and 45 kg/m2, respectively (these figures were somewhat higher, when the individual also has diabetes). Thus, while treating obesity to achieve a 5% reduction in body weight in someone with a BMI of 30 kg/m2 may never be “cost-effective”, the same amount of weight loss in someone with more extreme obesity, would likely pay for itself or even lead to significant savings. Because the impact of obesity on mental and physical health, life-expectancy and quality of life is also greatest at higher levels of BMI, one could also make a strong ethical argument for singling out these individuals for priority treatment in the health care system. Obviously, as readers should be aware, BMI is at best a crude measure for health – a more precise assessment would have used more sophisticated staging systems like the Edmonton Obesity Staging System to calculate individual risk and benefits. However, we should remember that at a population level BMI does… Read More »
Obesity In UK Show Dogs
As readers may be well aware, the obesity epidemic is by no means limited to humans – our pets are also affected (as, incidentally, are zoo animals). A paper by Such and German, published in Veterinary Record, shows that a significant proportion of show dogs in the UK would be considered to have overweight or obesity. The researchers did internet searches to identify 40 pictures per breed of 14 obese-prone dog breeds and 14 matched non-obese-probe breeds that had appeared at a major national UK show (Crufts). Of 1120 photographs initially identified, 960 were suitable for assessing body condition using a previously validated method, with all unsuitable images being from longhaired breeds. None of the dogs (0%) were underweight, 708 (74%) were in ideal condition and 252 (26%) were overweight with pugs, basset hounds and Labrador retrievers were most likely to be in the latter category. In contrast, standard poodles, Rhodesian ridgebacks, Hungarian vizslas and Dobermanns were least likely to be overweight. In the discussion, the authors wonder whether or not breed standards should be redefined to be consistent with a dog in optimal body condition (read – body weight). As someone, who could not really care less about breed standards and pedigrees (having shown dogs at dog shows myself as a kid), I find this paper of interest, as it reflects our thinking about appearances, that is by no means limited to animals. The mental health and physical benefits of owning a dog are well-documented – whether they meet show standards or not, is probably not what determines their usefulness as (wo)man’s best friend. @DrSharma Edmonton, AB
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