In a world of misinformation, Fitness Pudding is here to separate fact from fallacy, and science from fiction.
A client of mine stepped on the scale after a 12-week weight loss program, to find she had lost 6 lbs. She was ecstatic at her positive results, sharing a smile that would warm any heart. Later that day, another client from the same program stepped on the scale to discover she had also lost 6 lbs. Ecstatic right? No, she blasted off a few expletives, and wanted nothing more than to 'hulk smash' the scale to smithereens. With the varied responses to self-weighing, we might question whether it is good or bad. Also, does self-weighing even work to help lose weight?
Self-monitoring is a key feature of successful weight loss programs, and is consistently shown to be associated with weight loss.1 The aim of self-monitoring is to pay attention, on purpose, and evaluate a behavior as it relates to your goal(s), such as dietary and physical activity behavior – one big reason mobile fitness and dietary trackers are blowing up right now.
Self-weighing is a form of self-monitoring, allowing you to evaluate where you are, and what healthy behaviors should be adjusted. For example, past research has used a 'stop light' approach to maintaining a target weight. A target weight range is chosen, and if you are in that range, you have a 'green' light to keep eating healthfully and staying active. Keep doing what you are doing.
If you gain a few pounds out of your target range, you get a 'yellow' light, which triggers you to re-evaluate your behavior, and make subtle changes. If you get a bit too far out of your target range, you get a 'red' light, and more in-depth, healthy changes to behavior are needed. However, this type of monitoring system only works if you weigh often enough to see the small changes (yellow or red light), catching them before they turn into greater weight gain or unhealthy weight loss.
Assuming weight loss is needed, self-weighing frequency is commonly associated with lower body weight, moderate weight loss, less weight regain, and less weight gain.7,13,15 At the same time, decreasing self-weighing frequency is independently associated with weight gain.2 Self-weighing can also help promote other healthy, weight control behaviors, such as physical activity and dietary control.11,16
Weighing daily is commonly endorsed due to its relationship with greater weight loss, compared to those who weigh less than daily.7,9,11 A 90-day study with over 20,000 Lose It! app users found that each additional day of weighing (up to 90 days) was associated with an additional loss of .13 lbs.9 Also, a greater number of additional weight-control behaviors were adopted by those who weigh daily, compared to those who do not.11
Weighing once a week works well too. The National Weight Control Registry has found that 75% of those who have lost and maintained at least 30 lbs for 1 year or more, consistently weigh themselves at least once a week. Other research has found that participants classified as obese who weigh once weekly were 11 times more likely to lose at least 5% of their initial weight (gold-standard for weight loss and health) after 6 months.14
There is no direct evidence that weighing multiple times per day will be more beneficial than once a day or even once a week. Thus, at this time it appears that weighing daily or weekly are the best options, and more is not necessarily merrier.
There is concern that weighing too much might cause negative feelings, poor body image, and even eating disorders. At this time, research generally supports that regular self-weighing is associated with weight loss, but not with negative psychological outcomes (e.g. anxiety, depression) or eating disorders.6,12,15 However, there is evidence that self-weighing can promote adverse psychological and body image effects in some individuals, especially women and adolescents, but more evidence is needed in this area.5,8,10
In addition, not everyone in the research decides to weigh themselves. Those who do weigh daily or weekly seem to do better, but why do some people weigh less or avoid weighing entirely?
This question is a thrust of my own research, which has illustrated the negative feeling changes that can occur after common weight-related testing, differences in motivation types, and how we can cope in numerous ways. In general, we find that negative feelings are not all 'bad', as certain emotions, such as frustration, can help us change or try harder to achieve our goals. The key is to make sure we choose the right behaviors in response to this motivation – choosing healthy eating and physical activity versus a fad diet or disordered eating. On the other end of the spectrum, those who experience emotions like anxiety, depression, sadness and despondency, might not respond so positively to the self-weighing. It is these same emotions that make us want to avoid weighing in the first place! It is extremely helpful to know how you react when you weigh, both emotionally and behaviorally, which will help determine how helpful it might be for you.
Self-weighing once a day or once a week is commonly associated with weight loss and less weight gain, since it brings about awareness, and a chance to evaluate your healthy behaviors. Weighing more is not necessarily better, but being consistent is important. Research supports that weight loss takes place during periods of daily self-weighing, whereas breaks longer than one month pose a risk of weight gain.4 However, self-weighing might promote concerns of psychological distress, so those wanting to weigh too often might consider its usefulness in both weight control and psychological well-being.
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Dr. Faries has a Ph.D. in Behavioral Medicine and a Master of Science in Exercise Physiology, balanced with experience across the fitness industry, medicine, public health, research and extension.
His research explores why and how people initiate and maintain healthy behaviors, with focus on self-regulation success and failure. In other words, he seeks to better understand the common struggle with adopting healthy lifestyles, clarifying the reasons why we don’t “just do it.” Dr. Faries also holds unique expertise in medication adherence, when lifestyle is the medicine.
Dr. Faries also trains the next generation of ‘myth busters’ through medical and public health education, including his popular course, MythBusters: Health Edition.
Dr. Faries has served on the Board of Directors of the American College of Lifestyle Medicine, is founder of Lone Star Lifestyle Medicine for Texas, and is founder of FitnessPudding.com – a non-profit site dedicated to debunking common health and fitness myths.