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