Weekend Lifestyle and Body WeightTuesday, September 2, 2008
While I spent the long labour day weekend hiking to the top of Bear’s Hump Mountain in Waterton Lakes National Park and visiting the Head-Smashed-in Buffalo Jump and the Frank Slide Interpretive Centres in Southern Alberta, some of you may have been preparing to send your kids back to school or even getting ready for school yourself.
So now that the weekend is over, some of you may be wondering how weekend lifestyle patterns affect body weight.
This question was recently addressed in a randomised controlled trial comparing 1 year of caloric restriction (CR) with 1 year of daily exercise (EX) in 48 health adults aged 50-60 with BMIs between 23.5 and 29.9 (OBESITY). In this study, by Susan Racette and colleagues from the Washington University, St. Louis, Missouri, USA, participants were asked to measure body weight on 7 consecutive mornings for a total of 165 weeks at baseline and 437 weeks during the intervention.
At baseline, participants consistently gained weight on weekend days (around 0.06 kg/day), but not on weekdays. This was attributable to higher dietary intake on Saturdays and lower physical activity on Sundays relative to weekdays. During the interventions, both CR and EX participants were in negative energy balance on weekdays but on weekends, CR participants stopped losing weight, and EX participants actually gained weight (around 0.08 kg/day) due to higher dietary intakes on weekends.
The authors conclude that alterations in lifestyle behaviours on weekends contribute to weight gain or cessation of weight loss on weekends.
Not only do these results provide an explanation for the relatively slow rates of weight loss observed in many studies but they also highlight the importance of watching calories on the weekend (simply exercising is not enough!).
What do these data mean for long-term weight management?
Probably not much – remind your patients that weight maintenance, especially the prevention of weight regain, is a lifelong task – getting it right 5 days out of 7 is probably not so bad.
Don’t let the Monday reading on the scale spoil their mood – they’ve got till Friday to get ready for the weekend.
Or even better – tell them to only weigh themselves on Wednesdays, when they are hopefully back on track. It’s only when weight is up on two or more consecutive wednesdays that they need to really refocus their efforts.