Trying to lose weight? Keep it off? Confusing advice is abundant and one aspect of this confusion centers on recommendations to weigh-in: should you weigh yourself daily? weekly? monthly? or not at all? While I’m certainly not the first to comment on this issue, I hope to provide a fresh perspective that examines self-weighing in the context of complex systems.
Self-weighing, as I’ve discussed previously, is an example of feedback that tracks an outcome, the result of eating and physical activity behaviours. Distinguishing between outcome-based feedback (e.g. body weight) versus input-based feedback such as behaviours (e.g. calorie counting, logging physical activity) is important – the time frame over which measurable change occurs in an outcome may be significantly different compared to the time frame in which changes in an input behaviour can be observed.
A 2007 paper by Dr. Meghan Butryn and colleagues published in Obesity investigated the relationship between the frequency of self-weighing and successful weight loss maintenance.(1) Subjects were recruited from the National Weight Control Registry and asked to complete a self-weighing frequency assessment at the time they enrolled in the registry, as well as one year later. Although the researchers did not find a significant difference between the frequency of body weight measurement at baseline and the amount of weight regained at one year follow-up, weight regain was associated with a change in self-weighing frequency over the follow-up year. Subjects who indicated they weighed themselves less frequently at follow-up than at baseline reported significantly greater weight gain compared to subjects who reported either no change or an increase in the frequency of self-weighing.(1)
The authors explain the results by suggesting that “consistent and more intensive self-weighing may allow individuals to catch weight gains before they escalate and make behavior changes to prevent additional weight gain“.(1) I find this conclusion illogical, as it is not physiologically possible for daily fluctuations in body weight to exactly match daily variations in food consumption and physical activity. While the human body is not excepted from following the rules of thermodynamics, it takes time for the body to adapt (e.g. gain weight) in response to changes in caloric intake or energy expenditure. A one pound weight gain as measured by a scale may not be a reflection of true weight. It is very unlikely that subjects are catching potential weight gains early, as wearing different clothing, hydration status, and constipation, among other factors, can all easily influence body weight by more than a pound.
The frequency at which body weight is monitored cannot change the physical feedback delay in the body’s energy balance system. A longer time frame is necessary for accurate assessment of a meaningful trend in body weight. Then why is daily weighing associated with greater success at maintaining weight loss? Daily weighing may allow an individual to be more attuned to fluctuations in body weight. This behaviour may help them recognize the normal variability in their weight and that factors other than calories in and calories out contribute to this variability. Margart J. Wheatley suggests that creating multiple feedback loops helps connect different parts of a system to the whole.(2) This allows a shift in perspective, enabling the problem to be viewed differently. Realization of how body weight fluctuates over time may allow individuals to focus on their behaviours rather than the outcomes.
While this study by Butryn et al. supports measuring body weight daily for improved success in weight loss maintenance,(1) the results from this study should not be extrapolated to all weight loss scenarios. For example, in female adolescents, frequent weighing was found to be associated with unhealthy weight control behaviors and an increased frequency of binge eating.(3) This study and others also cannot answer whether daily weighing contributes to success in weight-loss maintenance or if it is the other way around; does successful weight-loss maintenance prompt daily weigh-ins?
So what is the optimal frequency to measure body weight? To successfully maintain weight loss, the evidence supports stepping on the scale daily.(1) This feedback connects the individual to the bigger picture, however it does not shorten the time-delay in receiving feedback about changes in body weight. Feedback loops created by monitoring behaviours such as counting steps taken or calories consumed have shorter delays. Consequently, these methods of self-monitoring may allow an individual to make more meaningful adjustments to their behaviour and set functional goals associated with behaviour change and weight loss.
For further reading on the subject of self-weighing, weight loss and weight loss maintenance, I highly recommend Dr. Yoni Freedhoff’s review of “A Self-Regulation Program for Maintenance of Weight Loss” by Wing et al. He also provides excellent advice on how to use a scale. His series of posts on scales and self-weighing can be found here. And if you like his blog, be sure to vote for him at the 2011 Best Health Blogs Awards.
1. Butryn, M., Phelan, S., Hill, J., & Wing, R. (2007). Consistent Self-monitoring of Weight: A Key Component of Successful Weight Loss Maintenance** Obesity, 15 (12), 3091-3096 DOI: 10.1038/oby.2007.368
2. The Servant -Leader: From Hero to Host – An Interview With Margaret Wheatley. (2002) http://www.margaretwheatley.com/articles/herotohost.html
3. Neumark-Sztainer D., van den Berg P., Hannan P.J., & Story, M. (2006) Self-weighing in adolescents: helpful or harmful? Longitudinal associations with body weight changes and disordered eating. J Adolesc Health. 39(6):811-8 PMID: 17116510