Monitoring Weight Daily Can Combat Weight Gain

Most commercial weight-loss programs discourage clients from weighing themselves daily because many factors, including normal fluid fluctuations, can influence the numbers on the scale. For example, Weight Watchers suggests members weigh only once a week to monitor weight and to maintain weight loss.

The freshman year of college is a notorious time for weight gain, particularly among college women. Cornell researchers recently sought to show that freshmen women might be able to avoid this weight gain by weighing themselves daily and having regular feedback from a professional staff (Int J Obesity January 31, 2006).

Dr. D. A. Levitsky and colleagues from the Division of Nutritional Sciences at Cornell University designed two independent studies. In the first, the researchers used an algorithmic method called the tissue monitoring system (TMS) to estimate changes in body tissue mass from changes in daily body weight. The TMS algorithm is used to estimate changes in body tissue mass from changes in daily body weight. With this method, fluctuations in body weight, are averaged over 7 days, giving a more accurate estimate of change in the weight of total body tissue.

The study group included 34 female freshmen between 18 and 21 years of age. The women were randomly assigned to an experimental or control group. All women were told that the study was about freshman weight gain and were given basic nutritional advice to eat three meals a day and to avoid snacking.

Women in the experimental group were given an analog bathroom scale and were advised to weigh themselves each morning immediately after arising from bed and before voiding. They then e-mailed their daily weight to the researchers. At the end of seven days, the staff e-mailed back a chart showing the day-by-day weights. A control group was weighed at the beginning and end of the semester, but had no contact with the staff between the 2 weigh-ins.

At the end of 10 weeks, the control group had gained a mean of 3.1 kg., while the experimental group gained less than 1 kg.

A second study with feedback

In the second study, 41 female freshmen 18 years of age or older were recruited through on-campus posters and introductory classes. Mean body weight was 62.0 kg. Participants were assigned to either a control group (24) or an experimental group (17). The purpose of the second study was to see if teaching portion sizes would have an impact on weight gain.

Each member of the experimental group received an analog scale and was instructed to weigh herself immediately after arising from bed and before voiding, similar to the previous study. They then e-mailed their daily weight to the research staff, who then entered it into a Microsoft Excel spreadsheet. In this study, each student received a value for the number of calories they needed to decrease to maintain a constant weight. After several days of data, the current body mass was estimated. The difference between the initial body mass and the current body mass was recalculated every day using the last seven points. The calculated level was then sent to each participant in an e-mail each day, accompanied by the following message: “In order to maintain the weight of your first seven days, you should___(increase/decrease) your intake by_____calories.” The control group was not contacted again until the last week of the semester. At this point, 10 weeks after the initial meeting, participants were reweighed wearing light clothing and no shoes.

The untreated control group gained an average of 2.0± 0.65 kg, whereas the experimental group lost a mean of 0.82±0.56 kg. The difference in weight gain between the two groups was statistically significant.

The results of the second study echoed the findings of the original study: freshmen women gain a significant amount of weight during their first semester at college, and providing these freshmen with information about their weight has an impact upon weight gain. On the average, adults who were provided feedback about their weight with the TMS gained less weight during the semester. According to the authors, both methods used in the first and second experiment was equally helpful in preventing weight gain during the 10-week semester.

Does frequent weighing lead to eating disorders?

The authors also addressed the issue of daily weighing as a precursor to developing an eating disorder. They cited a recent review by the National Task Force on the Prevention and Treatment of Obesity, which concluded that concerns that dieting individuals might develop psychological dysfunction in overweight and obese adults are not generally supported by empirical studies, and that knowledge of one’s tissue weight (as opposed to scale weight) may actually help prevent an eating disorder.