Weight cycling is the repeated episodes manifesting intentional weight loss and subsequent unintentional weight gain. Whether the frequency and magnitude of weight cycling is associated with colorectal cancer risk independent of body mass index (BMI) remains unknown.
Two prospective cohort studies, Nurses\' Health Study I and Health Professionals Follow-up Study, followed 85,562 participants from 1992 to 2014. Participants completed a questionnaire regarding the frequency and magnitude of intentional weight loss in the past 4 years at the baseline. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazard model.
We identified 1626 colorectal cancer cases during up to 22 years of follow-up. In the pooled analysis of HPFS and NHS, compared to non-weight cycling, moderate weight cycling (≥3 times of intentional weight loss of ≥2.3-4.4 kg) was associated with a reduced risk of colorectal cancer after adjustment for confounders, including attained BMI after weight cycling (HR = 0.82, 95% CI 0.69, 0.97). However, no significant association was observed in mild weight cyclers and in severe weight cyclers.
Moderate weight cycling was associated with a lower risk of colorectal cancer independent of BMI. This finding needs further studies for replication and putative biological mechanisms.

OBJECTIVE: Weight cycling is common in populations. However, it is unclear whether frequency and magnitude of weight cycling is associated with kidney cancer risk, independent of body mass index (BMI).
METHODS: A prospective cohort study followed 85,562 participants from Health Professionals Follow-up Study and Nurses\' Health Study (1992-2014). At baseline, participants reported frequency and magnitude of intentional weight loss in the past 4 years. Cox proportional hazard model was used to estimate hazard ratios (HR) and 95% confidence intervals (CI). We also conducted a meta-analysis of all available observational studies including our two cohorts.
RESULTS: During 22 years of follow-up, we identified 441 kidney cancer cases. Compared with non-weight cyclers (no attempt of intentional weight loss), severe cyclers (≥ 3 times of intentional weight loss of ≥ 4.5 kg) were at increased kidney cancer risk after adjusting for BMI before weight cycling (pooled multivariable-adjusted HR, 1.78; 95% CI, 1.19, 2.66). Additional adjustment for attained BMI after weight cycling had minimal influence. There was a positive trend between weight cycling by frequency and magnitude and kidney cancer risk (P-trend = 0.01). Moreover, the observed positive association did not differ by subtypes of cyclers (e.g., adiposity status, weight-loss methods). In the meta-analysis, we found a strong positive association between weight cycling and kidney cancer risk (summary relative risk for weight cyclers vs. non-cyclers, 1.51; 95% CI, 1.16, 1.96; I2: 52.2%; 6 studies).
CONCLUSIONS: Frequent substantial weight cycling was associated with increased risk of kidney cancer, independent of BMI. Our study suggests that weight cycling may be an important risk factor for kidney cancer.

Based in narrative phenomenology, this article describes an example of how lived time, self and bodily engagement with the social world intertwine, and how our sense of self develops. We explore this through the life story of a woman who lost weight through surgery in the 1970 s and has fought against her own body, food and eating ever since. Our narrative analysis of interviews, reflective notes and email correspondence disentangled two storylines illuminating paradoxes within this long-term weight loss process. Thea\'s Medical Weight Narrative: From Severely Obese Child to Healthy Adult is her story in context of medicine and obesity treatment and expresses success and control. Thea\'s Story: The Narrative of Fighting Weight is the experiential story, including concrete examples and quotes, highlighting bodily struggles and the inescapable ambiguity of being and having one\'s body. The two storylines coexist and illuminate paradoxes within the weight loss surgery narrative, connected to meaningful life events and experiences, eating practices and relationships with important others. Surgery was experienced as lifesaving, yet the surgical transformation did not suffice, because it did not influence appetite or, desire for food in the long run. In the medical narrative of transforming the body by repair, a problematic relationship with food did not fit into the plot.

Body weight variability (BWV) is common in the general population and may act as a risk factor for obesity or diseases. The correct identification of these patterns may have prognostic or predictive value in clinical and research settings. With advancements in technology allowing for the frequent collection of body weight data from electronic smart scales, new opportunities to analyze and identify patterns in body weight data are available.
This study aims to compare multiple methods of data imputation and BWV calculation using linear and nonlinear approaches.
In total, 50 participants from an ongoing weight loss maintenance study (the NoHoW study) were selected to develop the procedure. We addressed the following aspects of data analysis: cleaning, imputation, detrending, and calculation of total and local BWV. To test imputation, missing data were simulated at random and using real patterns of missingness. A total of 10 imputation strategies were tested. Next, BWV was calculated using linear and nonlinear approaches, and the effects of missing data and data imputation on these estimates were investigated.
Body weight imputation using structural modeling with Kalman smoothing or an exponentially weighted moving average provided the best agreement with observed values (root mean square error range 0.62%-0.64%). Imputation performance decreased with missingness and was similar between random and nonrandom simulations. Errors in BWV estimations from missing simulated data sets were low (2%-7% with 80% missing data or a mean of 67, SD 40.1 available body weights) compared with that of imputation strategies where errors were significantly greater, varying by imputation method.
The decision to impute body weight data depends on the purpose of the analysis. Directions for the best performing imputation methods are provided. For the purpose of estimating BWV, data imputation should not be conducted. Linear and nonlinear methods of estimating BWV provide reasonably accurate estimates under high proportions (80%) of missing data.

OBJECTIVE: Weight cycling is defined as cyclical loss and gain of weight and recent studies suggest deleterious effects of weight cycling on cardiometabolic health. We aimed to analyze the risk for diabetes development in association with weight cycling over 4 years of follow-up.
METHODS: A retrospective study performed in 4,818 non-diabetic participants (mean age 43 years, 78.3% men) in a health screening program in whom serial health examinations were performed in 5 consecutive years from 2010 to 2014. Average successive variability of weight (ASVW) was defined by the amount of body weight change in absolute value between the successive years over 5 years summed and divided by four. The subjects were divided into two groups according to body mass index (BMI), normal weight (<23 kg/m2) and overweight (≥23 kg/m2).
RESULTS: Over 4 years, 3.2% developed diabetes. When the subjects were divided into 3 groups according to tertile groups of ASVW, those in the highest tertile showed significantly increased risk for diabetes development compared to those with the lowest tertile {odds ratio (OR) 1.860; 95% CI 1.130-3.063}. When similar analyses were performed according to the 4 groups divided by baseline body weight and ASVW over four years, those who were more than overweight at baseline with high ASVW showed significantly increased risk of diabetes development compared to those had normal weight and low ASVW (OR 2.266; 95% 1.123-4.572). When the subjects were divided into six group according to weight change and ASVW, those with increased weight over 4 years and high ASVW showed the highest risk for diabetes development among the groups compared to those with stable weight and low ASVW over four years (OR 3.660; 95% CI 1.402-9.553).
CONCLUSIONS: Those with high ASVW showed significantly increased risk for diabetes development over four years compared with those who had low ASVW. Weight cycling was significantly associated with increased risk for diabetes.

Evidence about the health effects of weight cycling is not consistent, with some studies suggesting it is harmful for health. Here we investigated whether weight cycling was associated with weight change and mental health outcomes in 10,428 participants in the mid-age cohort of The Australian Longitudinal Study of Women\'s Health (ALSWH) over 12years. In 1998 the women were asked how many times they had ever intentionally lost at least 5kg and how many times had they regained this amount. Women were categorised into four weight pattern groups: frequent weight cyclers (FWC, three or more weight cycles), low frequency weight cyclers (LFWC, one or two weight cycles), non-weight cyclers (NWC), and weight loss only (WL). We used generalised linear modelling to investigate relationships between weight pattern group, weight change and mental health outcomes. In 1998, 15% of the women were FWC, 24% LFWC, 46% NWC and 15% were WL. Weight change was similar across weight pattern groups in women with obesity, however healthy weight and overweight FWC gained more weight than women who did not weight cycle. We found no difference in overall mental health scores between groups, but both LFWC and FWC had higher odds of depressive symptoms (adjusted OR 1.5, 95%CI: 1.1 to 1.9 and 1.7, 95%CI: 1.1 to 2.4, respectively) than NWC. Our results suggest that, although weight cycling is not associated with greater weight gain in women with obesity, it may increase depressive symptoms.

Although weight cycling is a common phenomenon in treatment-seeking patients with obesity, its consequences on health outcomes have not yet been completely clarified. We therefore aimed to investigate the effect of one cycle of intentional weight loss and regain on energy expenditure, body composition, cardiovascular risk factors and psychosocial variables in patients with severe obesity.
Clinical and psychosocial variables were measured in 38 adult patients with severe obesity (body mass index (BMI): 43.5 ± 7.2 kg/m2 ) consecutively readmitted to rehabilitative residential treatment (T1) for severe obesity after a cycle of weight loss (16.7 ±7.7 kg) and regain (15.1 ±11.3 kg), and compared with those recorded at a prior admission (T0).
No significant differences were found between T0 and T1 values for weight, BMI, waist circumference, total body fat percentage, fat-free mass percentage, respiratory quotient, measured or predicted resting energy expenditure, metabolic adaptation, cardiovascular risk factors or psychosocial variables. However, younger patients (r = -0.38, P = 0.023) and those with higher historical weight (r = 0.43, P = 0.010) tended to regain more weight.
The absence of negative physical and psychological effects of weight cycling indicates that the risk of weight regain should not be a barrier to encouraging weight loss efforts in patients with severe obesity.

Background: A formula low-energy diet (LED) reduces weight effectively in obese patients with knee osteoarthritis, but the role of LED in long-term weight-loss maintenance is unclear.Objective: We aimed to determine the effect of intermittent LED compared with daily meal replacements on weight-loss maintenance and number of knee replacements over 3 y.Design: The design was a randomized trial with participants aged >50 y who had knee osteoarthritis and a body mass index [BMI (in kg/m2)] ≥30. Participants were recruited from the osteoarthritis outpatient clinic at Copenhagen University Hospital in Frederiksberg, Denmark; they had previously completed a 68-wk lifestyle intervention trial and achieved an average weight loss of 10.5 kg (10% of initial body weight). Participants were randomly assigned to either the intermittent treatment (IN) group with LED for 5 wk every 4 mo for 3 y or to daily meal replacements of 1-2 meals for 3 y [regular (RE) group]. Attention by dietitians and the amount of formula products were similar. Primary outcomes were changes in body weight and proportion of participants receiving knee replacements. Outcomes were analyzed on the intention-to-treat-population with the use of baseline-carried-forward imputation for missing data.Results: A total of 153 participants (means ± SDs: BMI: 33.3 ± 4.6; age: 63.8 ± 6.3 y; 83% women) were recruited between June and December 2009 and randomly assigned to the IN (n = 76) or RE (n = 77) group. A total of 53 and 56 participants, respectively, completed the trial. Weight increased by 0.68 and 1.75 kg in the IN and RE groups, respectively (mean difference: -1.06 kg; 95% CI: -2.75, 0.63 kg; P = 0.22). Alloplasty rates were low and did not differ (IN group: 8 of 76 participants; RE group: 12 of 77 participants; P = 0.35).Conclusions: After a mean 10% weight-loss and 1-y maintenance, additional use of daily meal replacements or intermittent LED resulted in weight-loss maintenance for 3 y. These results challenge the commonly held assumption that weight regain in the long term is inevitable. This trial was registered at clinicaltrials.gov as NCT00938808.

OBJECTIVE: This study aimed to investigate whether repeated lifestyle interventions lead to progressive weight loss or to weight cycling.
METHODS: A retrospective review chart study with follow-up on 2120 participants (mean±SD age 36±15 years; body weight 116±28 kg; fat 43±6%). All had participated in one to four 11-12 week lifestyle interventions (residential weight loss programme, mixed activities). Weight loss was promoted through a hypocaloric diet (-500 to -700 kcal/day) and daily physical activity (1-3 hours/day). Primary outcomes were weight loss and change in body composition (bioimpedance measurements) after the intervention periods and at follow-up.
RESULTS: A total of 2120, 526, 139 and 47 people participated in one to four interventions with mean±SEM times from start to follow-up of 1.3±0.1, 2.9±0.2, 4.2±0.3 and 5.2±0.4 years respectively. Overall 50, 41, 18 and 11% of the participants were lost to follow-up after one to four interventions, respectively. The cumulated weight loss at follow-up increased with the number of interventions from one to four: 12.2±0.1, 15.9±0.7, 16.1±1.2 and 18.5±2.0 kg ( p<0.001). The ratios between cumulated loss of fat and fat free mass after one to four interventions decreased with the number of interventions (2.4, 2.2, 2.1 and 1.4). Rates of weight loss during the interventions ranged from 0.70±0.06 to 1.06±0.01 kg/week and the maximum weight regain during the follow-up periods was 0.039±0.007 kg/week.
CONCLUSIONS: Repeated relatively short lifestyle interventions in a selected and motivated group can be an efficient method for weight loss maintenance with only limited body weight cycling in the interim periods. However, the relationship between loss of fat and fat free mass might change in an unfavourable direction.

OBJECTIVE: To explore the impact of body weight change following intentional weight loss on measures of physical performance in adults with diabetes.
METHODS: 450 individuals with type 2 diabetes (age: 59.0±6.9 years, BMI: 35.5±5.9 kg/m2) who participated in the Look AHEAD Movement and Memory Study and lost weight one year after being randomized to an intensive lifestyle intervention were assessed. Body weight was measured annually, and participants were categorized as continued losers/maintainers, regainers, or cyclers based on a ±5% annual change in weight. Objective measures of physical performance were measured at the year 8/9 visit.
RESULTS: Forty-four, 38 and 18% of participants were classified as regainers, cyclers, and continued losers/maintainers. In women, weight cycling and regain was associated with worse follow-up expanded physical performance battery score (1.46±0.07 and 1.48±0.07 vs. 1.63±0.07, both p≤0.02) and slower 20-meter walking speed (1.10±0.04 and 1.08±0.04 m/s vs. 1.17±0.04 m/s, both p<0.05) compared to continued or maintained weight loss. Male cyclers presented with weaker grip strength compared to regainers or continued losers/maintainers (30.12±2.21 kg versus 34.46±2.04 and 37.39±2.26 kg; both p<0.01).
CONCLUSIONS: Weight cycling and regain following intentional weight loss in older adults with diabetes was associated with worse physical function in women and grip strength in men.