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How Do People With Obesity Spend Their Time?

time spiralWe live in a time where most of us complain about the lack of it. Thus, I often remind myself that our “fast-food culture” is more a time than a food problem.

Now a study by Viral Patel and colleagues, published in OBESITY, takes a detailed look at how US Americans spend their time according to different BMI categories.

The researchers analyse data from over 28,503 observations of individuals aged 22 to 70 from the American Time Use Survey, a continuous cross-sectional survey on time use in the USA.

In a statistical model that adjusted for various sociodemographic, geographic, and temporal characteristics, younger age; female sex; Asian race; higher levels of education; family income >$75 k; self-employment; and residence in the West or Northeast census regions were all associated with a lower BMI relative to reference categories whereas age 50 to 59 years; Black, Hispanic, or “other” race; and not being in the labor force were associated with a higher BMI.

That said, here are the differences in time use associated with higher BMI:

Although there were no substantial differences among BMI categories in time spent sleeping, overweight individuals experienced almost 20 fewer minutes of sleeplessness on weekends/holidays than individuals with normal weight. Furthermore, there was a U-shaped relationship between BMI and sleep duration such that BMI was lowest when sleep duration was approximately 8 h per day and increased as sleep duration became both shorter and longer. Less sleep on weekends and holidays (5 to 7 h) was also associated with higher BMI than 8 to 9 h or sleep.

There were also no major differences between BMI categories and the odds of participating in work or in the amount of time working. However, working 3-4 h on weekends/holidays was associated with the lowest BMI. Individuals with obesity were more likely to be working between 3:30 a.m. and 7:00 a.m. on weekdays than normal-BMI individuals, again perhaps cutting into restful sleep.

Individuals with obesity were less likely to participate in food and drink preparation than individuals with normal weight on weekdays but spent about the same amount of time eating or drinking as the reference category.

Interestingly, individuals with obesity were more likely than individuals with normal weight to participate in health-related self-care, and overweight individuals spent over 1 h more on weekdays than individuals with normal weight on health-related self-care and also spent an additional 15 min (almost double the time) on professional and personal care services.

While individuals with higher BMI were less likely to participate in sports, exercise, and recreation on weekdays and weekends/holidays compared with individuals with normal weight, those who did participate did not differ from individuals with normal weight in the amount of time spent participating. In contrast, overweight individuals were more likely to attend sports/recreation events during the week and spent an additional 47 min (almost 25% more) on this activity than individuals with normal weight.

Overall, there was a positive and generally linear association between time spent viewing television/movies and BMI, with individuals with obesity more likely to watch television almost all hours of the day during the week and weekends.

On weekends/holidays, individuals with obesity were more likely to participate in care for household children and household adults. It was also observed that individuals with obesity spent an additional 15 min on religious and spiritual activities on weekends/holidays, compared with normal-BMI individuals (who spent 116 min).

While these data are of interest and are largely consistent with the emerging data on the role of optimal sleep duration and the detrimental impact of sedentary activities like television viewing on body weight, we must remember that the data are cross-sectional in nature and cannot be interpreted to imply causality (as, unfortunately, the authors do throughout their discussion).

Also, no correction is made for increasing medical, mental, or functional limitations associated with increasing BMI levels, which may well substantially affect time use including sleep, work, participation in sports or work-related activities.

Thus, it is not exactly clear what lessons one can learn regarding possible interventions – it is one thing to describe behaviours – it is an entirely different thing to try and understand why those behaviours occur in the first place.

Thus, unfortunately, findings from these type of studies too often feed into the simplistic and stereotypical “obesity is a choice” narrative, which does little more than promote weight bias and discrimination.

@DrSharma
Edmonton, AB

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Severity Of Sleep Apnea Is Related To Distance From Sleep Centre

sharma-obesity-sleepapnea1Although sleep apnea is one of the most common and devastating complications of obesity, it remains woefully under-diagnosed and under-treated.

One factor accounting for this may well be the lack of timely access to sleep testing.

Now, a study by Hirsch Allen and colleagues from the University of British Columbia Hospital Sleep Clinic, published in the Annals of the American Thoracic Society, examined the relationship between severity of sleep apnea and travel times to the clinic in 1275 patients referred for suspected sleep apnea.

After controlling for a number of confounders including gender, age, obesity and education, travel time was a significant predictor of OSA severity with each 10 minute increase in travel time associated with an apnea-hypopnea-index increase of 1.4 events per hour.

The most likely explanation for these findings is probably related to the fact that the more severe the symptoms, the more likely patients are to travel longer distances to undergo a sleep study.

Thus, travel distance may well be a significant barrier for many patients accounting for a large proportion of undiagnosed sleep apnea – at least for milder forms.

Given the often vast distances in Canada one can only wonder about just how much sleep apnea goes under diagnosed because of this issue.

@DrSharma
Edmonton, AB

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Effect Of Sleep Deprivation And Meal Timing On Insulin Sensitivity

sharma-obesity-sleep-deprivationAs we continue learning more about the complexity of appetite and energy balance, sleep and circadian rhythm are emerging as important variables.

Now a study by Robert Eckel and colleagues, published in Current Biology, illustrates how sleep deprivation and timing of meals can markedly alter insulin sensitivity.

Studies were conducted in 16 healthy young adults (8w) with normal BMI. Following a week of 9-hr-per-night sleep schedules, subjects were studied in a crossover counterbalanced design with 9-hr-per-night adequate sleep (9-hr) and 5-hr-per-night short sleep duration (5-hr) conditions lasting 5 days each, to simulate a 5-day work week. Sleep was restricted by delaying bedtime and advancing wake time by 2 hr each.

Energy balanced diets continued during baseline, whereas food intake was ad libitum during scheduled wakefulness of 5- and 9-hr conditions.

Overall, the simulated 5-day work week  of 5-hr-per-night sleep together with an ad libitum diet resulted in a 20% decrease in oral and intravenous insulin sensitivity, which was compensated for by increased insulin secretion..

These changes persisted for up to 5 days after restoring 9-hr sleep opportunities.

The authors also showed that shifting circadian rhythm resulted in morning wakefulness and eating during the biological night, a factor that may promote weight gain over time.

 

These findings have important implications not just for shift workers but for all of us, who may not be getting adequate amounts of restorative sleep.
Paying more attention to sleep and its impact on appetite and metabolism may need to find its way into routine clinical practice.
@DrSharma
Vienna, Austria
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The Biology Of The Food Coma

sharma-obesity-sleep-deprivationFeeling ready for a nap after a meal is part of normal human physiology – but how exactly does this happen?

Now, Christophe Varin and colleagues from the Centre National de la Recherche Scientifique, Paris, France, in a paper published in the Journal of Neuroscience describe how glucose regulates key neurones in the brain to induce sleepiness.

Their studies in mice focussed on sleep-active neurons located in the ventrolateral preoptic nucleus (VLPO), critical in the induction and maintenance of slow-wave sleep (SWS).

Using both in vivo and ex vivo patch clamp studies, the researchers show that a rise in extracellular glucose concentration in the VLPO can promote sleep by increasing the activity of sleep-promoting VLPO neurons.

As the researchers note,

“The extracellular glucose concentration monitors the gating of KATP channels of sleep-promoting neurons, highlighting that these neurons can adapt their excitability according to the extracellular energy status… Glucose-induced excitation of sleep-promoting VLPO neurons should therefore be involved in the drowsiness that one feels after a high-sugar meal. This novel mechanism regulating the activity of VLPO neurons reinforces the fundamental and intimate link between sleep and metabolism.”

Apart from helping unravel the biology of a phenomenon that every parent of a young child is well aware of, this research raises a number of interesting clinical questions.

Does overconsumption of high-sugar foods necessitate counteracting these effects with caffeine? Is this why sugar-sweetened pop generally contains caffeine (to not put you to sleep)?

Does this also explain the practice of eating a bedtime snack to fight insomnia?

And what does this mean for people with poorly controlled diabetes: do they need to drink more coffee than people without diabetes to get through their day? (not something I’ve heard of).

Interesting stuff…

@DrSharma
Berlin, Germany

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Early Bird Registration For Canadian Obesity Summit Ends March 3rd

For all my Canadian readers (and any international readers planning to attend), here just a quick reminder that the deadline for early bird discount registration for the upcoming 4th Canadian Obesity Summit in Toronto, April 28 – May 2, ends March 3rd.

To anyone who has been at a previous Canadian Summit, attending is certainly a “no-brainer” – for anyone, who hasn’t been, check out these workshops that are only part of the 5-day scientific program – there are also countless plenary sessions and poster presentations – check out the full program here.

Workshops:

Public Engagement Workshop (By Invitation Only)

Pre-Summit Prep Course – Overview of Obesity Management ($50)

Achieving Patient‐Centeredness in Obesity Management within Primary Care Settings

Obesity in young people with physical disabilities

CON-SNP Leadership Workshop: Strengthening CON-SNP from the ground up (Invitation only)

Exploring the Interactions Between Physical Well-Being and Obesity

Healthy Food Retail: Local public‐private partnerships to improve availability of healthy food in retail settings

How Can I Prepare My Patient for Bariatric Surgery? Practical tips from orientation to operating room

Intergenerational Determinants of Obesity: From programming to parenting

Neighbourhood Walkability and its Relationship with Walking: Does measurement matter?

The EPODE Canadian Obesity Forum: Game Changer

Achieving and Maintaining Healthy Weight with Every Step

Adolescent Bariatric Surgery – Now or Later? Teen and provider perspectives

Preventive Care 2020: A workshop to design the ideal experience to engage patients with obesity in preventive healthcare

Promoting Healthy Maternal Weights in Pregnancy and Postpartum

Rewriting the Script on Weight Management: Interprofessional workshop

SciCom-muniCON: Science Communication-Sharing and exchanging knowledge from a variety of vantage points

The Canadian Task Force on Preventive Health Care’s guidelines on obesity prevention and management in adults and children in primary care

Paediatric Obesity Treatment Workshop (Invitation only)

Balanced View: Addressing weight bias and stigma in healthcare

Drugs, Drinking and Disordered Eating: Managing challenging cases in bariatric surgery

From Mindless to Mindful Waiting: Tools to help the bariatric patient succeed

Getting Down to Basics in Designing Effective Programs to Promote Health and Weight Loss

Improving Body Image in Our Patients: A key component of weight management

Meal Replacements in Obesity Management: A psychosocial and behavioural intervention and/or weight loss tool

Type 2 Diabetes in Children and Adolescents: A translational view

Weight Bias: What do we know and where can we go from here?

Energy Balance in the Weight- Reduced Obese Individual: A biological reality that favours weight regain

Innovative and Collaborative Models of Care for Obesity Treatment in the Early Years

Transition of Care in Obesity Management : Bridging the gap between pediatric and adult healthcare services

Neuromuscular Meeting workshop – Please note: Separate registration is required for this event at no charge

To register – click here.

@DrSharma
Edmonton, AB

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