Composition of two-week change in body weight under unrestricted free-living conditions

Validation of remote child weight and height measurements within a weight management trial

OBJECTIVE

The aim of this substudy within the Treatment Efforts Addressing Child Weight Management by Unifying Patients, Parents, and Providers (TEAM UP) pragmatic clinical trial was to compare the validity of anthropometric measurements collected remotely versus in person (≤7 days apart) among youth with obesity who were 6 to 15 years of age.

METHODS

Child (n = 37) weight and height were measured in person by a trained data assessor. These were compared with measurements taken remotely by the child's parent with live videoconferencing observation by a study data assessor. In-person and remote measurements were compared using Bland-Altman plots, Pearson correlations, and two one-sided paired t tests. A priori bounds of acceptability were set at ±0.68 kg to allow for typical weight fluctuations within the 7-day comparison period.

RESULTS

Measurements were highly correlated (height: r = 0.991, p < 0.0001; weight: r = 0.999; p = 0.03). For height, two one-sided t tests for upper, t(36) = 3.95, and lower, t(36) = -2.63, bounds (-1, 1) revealed an overall p = 0.006; absolute error was 3.5 cm. For weight, two one-sided t tests for upper, t(36) = 1.93, and lower, t(36) = -7.91, bounds (-0.68, 0.68) revealed an overall p = 0.03; absolute error was 1.7 kg.

CONCLUSIONS

The present findings support the utility and interpretation of remotely assessed weight management outcomes for both research and clinical purposes. These procedures may offer greater accessibility to evidence-based measurement.

Validation of remote anthropometric measurements in a rural randomized pediatric clinical trial in primary care settings

Rural children are more at risk for childhood obesity but may have difficulty participating in pediatric weight management clinical trials if in-person visits are required. Remote assessment of height and weight observed via videoconferencing may provide a solution by improving the accuracy of self-reported data. This study aims to validate a low-cost, scalable video-assisted protocol for remote height and weight measurements in children and caregivers. Families were provided with low-cost digital scales and tape measures and a standardized protocol for remote measurements. Thirty-three caregiver and child (6-11 years old) dyads completed remote (at home) height and weight measurements while being observed by research staff via videoconferencing, as well as in-person measurements with research staff. We compared the overall and absolute mean differences in child and caregiver weight, height, body mass index (BMI), and child BMI adjusted Z-score (BMIaz) between remote and in-person measurements using paired samples t-tests and one sample t-tests, respectively. Bland-Altman plots were used to estimate the limits of agreement (LOA) and assess systematic bias. Simple regression models were used to examine associations between measurement discrepancies and sociodemographic factors and number of days between measurements. Overall mean differences in child and caregiver weight, height, BMI, and child BMIaz were not significantly different between remote and in-person measurements. LOAs were - 2.1 and 1.7 kg for child weight, - 5.2 and 4.0 cm for child height, - 1.5 and 1.7 kg/m2 for child BMI, - 0.4 and 0.5 SD for child BMIaz, - 3.0 and 2.8 kg for caregiver weight, - 2.9 and 3.9 cm for caregiver height, and - 2.1 and 1.6 kg/m2 for caregiver BMI. Absolute mean differences were significantly different between the two approaches for all measurements. Child and caregiver age were each significantly associated with differences between remote and in-person caregiver height measurements; there were no significant associations with other measurement discrepancies. Remotely observed weight and height measurements using non-research grade equipment may be a feasible and valid approach for pediatric clinical trials in rural communities. However, researchers should carefully evaluate their measurement precision requirements and intervention effect size to determine whether remote height and weight measurements suit their studies.Trial registration: ClinicalTrials.gov NCT04142034 (29/10/2019).

Low gestational weight gain (+2.0 to 4.9 kg) for singleton-term gestations associated with favorable perinatal outcomes for all prepregnancy obesity classes

BACKGROUND

Previous studies that evaluated low gestational weight gain or weight loss among prepregnancy obesity classes have not determined the amount of gestational weight gain associated with the lowest risk of adverse perinatal outcomes and neonatal morbidity among singleton term births.

OBJECTIVE

This study aimed to evaluate the relationship of specific gestational weight gain categories of weight loss, stable weight, and low gain considered below the 2009 Institute of Medicine guidelines to perinatal outcomes and neonatal morbidity for singleton, term live births among prepregnancy obesity classes.

STUDY DESIGN

This was a retrospective cohort study of 18,476 women among 3 classes of prepregnancy obesity, based on measured prepregnancy weight, and delivering a live singleton pregnancy at ≥37 weeks of gestation at a Kaiser Permanente Northern California hospital (2009-2012). Variables from electronic medical records included perinatal outcomes, sociodemographics, and measured prepregnancy and delivery weights to calculate total gestational weight gain, used to define 5 gestational weight gain categories: weight loss (<-2.0 kg), stable weight (-2.0 to +1.9 kg), low gain (+2.0 to 4.9 kg), gain within guidelines (+5.0 to 9.1 kg; referent), and gain above guidelines (>9.1 kg). Logistic regression models estimated adjusted odds ratios and 95% confidence intervals of maternal and newborn perinatal outcomes (hypertensive disorders, cesarean delivery, size for gestational age, length of stay, neonatal intensive care unit admission) associated with gestational weight gain categories stratified by prepregnancy obesity classes 1, 2, and 3.

RESULTS

Low gain occurred in 8%, 12%, and 13% of women in obesity class 1 (body mass index, 30.0-34.9), class 2 (body mass index, 35.0-39.9), and class 3 (body mass index, ≥40), respectively. Compared with gestational weight gain within Institute of Medicine guidelines, low gain was associated with similar or improved maternal and newborn perinatal outcomes for all obesity classes without increased odds of neonatal intensive care unit admission, neonatal length of stay ≥3 days, or small for gestational age. The percentages of small for gestational age for the low gain category were 4.4%, 3.0%, and 4.3% among prepregnancy obesity classes 1, 2, and 3, respectively, and comparable with the gestational weight gain within the guideline category (P>.05). The adjusted odds ratios of small-for-gestational age were not statistically significant for all obesity classes; class 1 (1.16; 95% confidence interval, 0.79-1.71) , class 2 (1.05; 95% confidence interval 0.58-1.93), and class 3 (2.03; 95% confidence interval 0.97-4.27).

CONCLUSION

Lower gestational weight gain of +2.0 to 4.9 kg showed the most favorable perinatal outcomes, without higher small for gestational age or neonatal morbidity for all obesity classes.

Optimizing maintenance dosing of emicizumab-kxwh as prophylaxis in hemophilia A: Dosing to product labeling while minimizing drug waste

BACKGROUND: The introduction of the bispecific antibody emicizumab-kxwh has driven a paradigm shift in the management of patients with hemophilia A. Emicizumab-kxwh is gradually replacing factor VIII as the treatment of choice for prophylaxis. The requirement to dose emicizumab-kxwh by weight can drive waste when the appropriate combination of various strengths of single-use vials is not considered, whereas inappropriate rounding to full vials can lead to significantly subtherapeutic or supratherapeutic doses. OBJECTIVE: To quantify waste reduction and impact to savings when a clinical program designed to optimize the emicizumab-kxwh dose, frequency, and vial combination is applied at the dispensing specialty pharmacy level. METHODS: The electronic medical records of 360 patients receiving emicizumab-kxwh as maintenance therapy were retrospectively reviewed. Patients were included in the sample if they were male, were aged 18 to 89 years, were inhibitor negative, and had at least 1 new or renewal maintenance prescription in 2021. Three hundred seventy discrete regimens were identified as evaluated per the Regimen Optimization Algorithm - emicizumab-kxwh and included in the final sample. Data collected for each regimen included patient weight, emicizumab-kxwh dose and interval originally prescribed, every 7-day equivalent regimen (to the hundredth of a milligram), vial combination originally ordered, and resulting waste generated. For those regimens failing the algorithm, additional review of pharmacist follow-up and prescriber engagement was performed. When the prescriber adopted a pharmacist recommendation to adjust dose, frequency of administration and/or vial combination, impact to cost was calculated (Medicare Part B 2022 average sale price). RESULTS: 48% (176/370) of reviewed regimens failed specialty pharmacist review because they drove a potentially subtherapeutic or supratherapeutic dose and/or resulted in the use of partial vials that required that the patient discard all emicizumab-kxwh over the prescribed amount with each dose. 112 (64%) of these failed regimens met full criteria for prescriber engagement to recommend a regimen adjustment to dose, frequency of administration, and/or vial combination. These recommendations were adopted in 43% of cases (48/112), resulting in a cumulative savings of 600 mg per dose while also avoiding significant subtherapeutic or supratherapeutic dosing. When factoring in the frequency of administration at the patient level, cumulative annual savings to payers across these 48 accepted recommendations was $1,793,549.76. CONCLUSIONS: These data illustrate that the application of an evidence-based Regimen Optimization Algorithm at the dispensing specialty pharmacy level can reduce waste and drive payer savings while avoiding significant subtherapeutic or supratherapeutic dosing. DISCLOSURES: Accredo, Inc, a specialty pharmacy dispensing emicizumab-kxwh to patients with hemophilia A, employs the authors. Accredo, Inc, is a subsidiary of EverNorth, which also includes Express Scripts, a PBM that adjudicates a portion of emicizumab-kxwh claims.

Recruiting participants for ergonomic research using self-reported stature and body mass

BACKGROUND

A valid distribution of key anthropometric parameters among participants is often a perquisite of ergonomics research.

OBJECTIVE

In this paper, we investigated the accuracy of self-reported stature and body mass of the population in the Netherlands.

METHODS

Data from 4 experiments was synthesized where in each experiment, participants self-reported their stature and body mass prior to being measured, of which they were not notified before.

RESULTS

Statistical analysis of 249 records indicated that on average, participants overreported their stature by 1.31 cm and underreported their mass by 1.45 kg. This is especially true for people with a BMI≥25.

CONCLUSION

Two models were proposed to adjust the self-reported stature and body mass for ergonomic researchers in a survey or recruitment. Limitations in using the models are highlighted as well.

Weight Cycling in Women: Adaptation or Risk?

Obesity, dieting, and weight cycling are common among reproductive-age women. Weight cycling refers to intentional weight loss followed by unintentional weight regain. Weight loss is accompanied by changes in gut peptides, adipose hormones, and energy expenditure that promote weight regain to a tightly regulated set point. While weight loss can improve body composition and surrogate markers of cardiometabolic health, it is hypothesized that the weight regain can result in an overshoot effect, resulting in excess weight gain, altered body composition, and negative effects on surrogate markers of cardiometabolic health. Numerous observational studies have examined the association of weight cycling and health outcomes. There appears to be modest association between weight cycling with type 2 diabetes mellitus and dyslipidemia in women, but no association with hypertension, cardiovascular events, and overall cancer risk. Interestingly, mild weight cycling may be associated with a decreased risk of overall and cardiovascular mortality. Little is known about the effects of weight cycling in the preconception period. Although obesity and weight gain are associated with pregnancy complications, preconception weight loss does not appear to mitigate the risk of most pregnancy complications related to obesity. Research on preconception weight cycling may provide insight into this paradox.

Effect of Sleep Extension on Objectively Assessed Energy Intake Among Adults With Overweight in Real-life Settings: A Randomized Clinical Trial

IMPORTANCE

Short sleep duration has been recognized as a risk factor for obesity. Whether extending sleep duration may mitigate this risk remains unknown.

OBJECTIVE

To determine the effects of a sleep extension intervention on objectively assessed energy intake, energy expenditure, and body weight in real-life settings among adults with overweight who habitually curtailed their sleep duration.

DESIGN, SETTING, AND PARTICIPANTS

This single-center, randomized clinical trial was conducted from November 1, 2014, to October 30, 2020. Participants were adults aged 21 to 40 years with a body mass index (calculated as weight in kilograms divided by height in meters squared) between 25.0 and 29.9 and had habitual sleep duration of less than 6.5 hours per night. Data were analyzed according to the intention-to-treat principle.

INTERVENTIONS

After a 2-week habitual sleep period at baseline, participants were randomized to either an individualized sleep hygiene counseling session that was intended to extend their bedtime to 8.5 hours (sleep extension group) or to continue their habitual sleep (control group). All participants were instructed to continue daily routine activities at home without any prescribed diet or physical activity.

MAIN OUTCOMES AND MEASURES

The primary outcome was change in energy intake from baseline, which was objectively assessed as the sum of total energy expenditure and change in body energy stores. Total energy expenditure was measured by the doubly labeled water method. Change in body energy stores was computed using regression of daily home weights and body composition changes from dual-energy x-ray absorptiometry. Sleep duration was monitored by actigraphy. Changes from baseline were compared between the 2 groups using intention-to-treat analysis.

RESULTS

Data from 80 randomized participants (mean [SD] age, 29.8 [5.1] years; 41 men [51.3%]) were analyzed. Sleep duration was increased by approximately 1.2 hours per night (95% CI, 1.0 to 1.4 hours; P < .001) in the sleep extension group vs the control group. The sleep extension group had a significant decrease in energy intake compared with the control group (-270 kcal/d; 95% CI, -393 to -147 kcal/d; P < .001). The change in sleep duration was inversely correlated with the change in energy intake (r = -0.41; 95% CI, -0.59 to -0.20; P < .001). No significant treatment effect in total energy expenditure was found, resulting in weight reduction in the sleep extension group vs the control group.

CONCLUSIONS AND RELEVANCE

This trial found that sleep extension reduced energy intake and resulted in a negative energy balance in real-life settings among adults with overweight who habitually curtailed their sleep duration. Improving and maintaining healthy sleep duration over longer periods could be part of obesity prevention and weight loss programs.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02253368.

Total energy expenditure is repeatable in adults but not associated with short-term changes in body composition

Low total energy expenditure (TEE, MJ/d) has been a hypothesized risk factor for weight gain, but repeatability of TEE, a critical variable in longitudinal studies of energy balance, is understudied. We examine repeated doubly labeled water (DLW) measurements of TEE in 348 adults and 47 children from the IAEA DLW Database (mean ± SD time interval: 1.9 ± 2.9 y) to assess repeatability of TEE, and to examine if TEE adjusted for age, sex, fat-free mass, and fat mass is associated with changes in weight or body composition. Here, we report that repeatability of TEE is high for adults, but not children. Bivariate Bayesian mixed models show no among or within-individual correlation between body composition (fat mass or percentage) and unadjusted TEE in adults. For adults aged 20–60 y (N = 267; time interval: 7.4 ± 12.2 weeks), increases in adjusted TEE are associated with weight gain but not with changes in body composition; results are similar for subjects with intervals >4 weeks (N = 53; 29.1 ± 12.8 weeks). This suggests low TEE is not a risk factor for, and high TEE is not protective against, weight or body fat gain over the time intervals tested.

Low total energy expenditure (TEE) has been a hypothesized risk factor for weight gain, but longitudinal repeatability of TEE is incompletely understood. Here the authors report that TEE is repeatable for adults, but not for children, and increases in TEE (adjusted for fat-free mass, fat mass, age and sex) are not associated with body composition changes in short-term longitudinal analyses.

Diet and lifestyle behaviour disruption related to the pandemic was varied and bidirectional among US and UK adults participating in the ZOE COVID Study

Evidence of the impact of the COVID-19 pandemic on health behaviours in the general population is limited. In this retrospective longitudinal study including UK and US participants, we collected diet and lifestyle data pre-pandemic (896,286) and peri-pandemic (291,871) using a mobile health app, and we computed a bidirectional health behaviour disruption index. Disruption of health behaviour was higher in younger, female and socio-economically deprived participants. Loss in body weight was greater in highly disrupted individuals than in those with low disruption. There were large inter-individual changes observed in 46 health and diet behaviours measured peri-pandemic compared with pre-pandemic, but no mean change in the total population. Individuals most adherent to less healthy pre-pandemic health behaviours improved their diet quality and weight compared with those reporting healthier pre-pandemic behaviours, irrespective of relative deprivation; therefore, for a proportion of the population, the pandemic may have provided an impetus to improve health behaviours. Public policies to tackle health inequalities widened by the pandemic should continue to prioritize diet and physical activity for all, as well as more targeted approaches to support younger females and those living in economically deprived areas.

Estimating 24-Hour Urinary Excretion of Sodium and Potassium Is More Reliable from 24-Hour Urine Than Spot Urine Sample in a Feeding Study of US Older Postmenopausal Women

BACKGROUND

Assessing estimated sodium (Na) and potassium (K) intakes derived from 24-h urinary excretions compared with a spot urine sample, if comparable, could reduce participant burden in epidemiologic and clinical studies.

OBJECTIVES

In a 2-week controlled-feeding study, Na and K excretions from a 24-h urine collection were compared with a first-void spot urine sample, applying established algorithms and enhanced models to estimate 24-h excretion. Actual and estimated 24-h excretions were evaluated relative to mean daily Na and K intakes in the feeding study.

METHODS

A total of 153 older postmenopausal women ages 75.4 ± 3.5 y participated in a 2-wk controlled-feeding study with a 4-d repeating menu cycle based on their usual intake (ClinicalTrials.gov Identifier: NCT00000611). Of the 150 participants who provided both a first-void spot urine sample and a 24-h urine collection on the penultimate study day, statistical methods included Pearson correlations for Na and K between intake, 24-h collections, and the 24-h estimated excretions using 4 established algorithms: enhanced biomarker models by regressing ln-transformed intakes on ln-transformed 24-h excretions or ln-transformed 24-h estimated excretions plus participant characteristics and sensitivity analyses for factors potentially influencing Na or K excretion (e.g., possible kidney disease estimated glomerular filtration rate <60 mL/min/1.73 m2 ).

RESULTS

Pearson correlation coefficients between Na and K intakes and actual 24-h excretions were 0.57 and 0.38-0.44 for estimated 24-h excretions, depending on electrolyte and algorithm used. Enhanced biomarker model cross-validated R 2 (CVR2) for 24-h excretions were 38.5% (Na), 40.2% (K), and 42.0% (Na/K). After excluding participants with possible kidney disease, the CVR2 values were 43.2% (Na), 40.2% (K), and 38.1% (Na/K).

CONCLUSIONS

Twenty-four-hour urine excretion measurement performs better than estimated 24-h excretion from a spot urine as a biomarker for Na and K intake among a sample of primarily White postmenopausal women.

Growth assessment of children during the COVID-19 pandemic-Can we rely on parental measurements?

Aim

The COVID‐19 pandemic prompted the rapid development of remote medical services. During lockdown periods, children's growth data were obtained from parents’ home assessments. This study aimed to assess the accuracy of home height and weight measurements and analyse their utility in clinical decision‐making.

Methods

A retrospective, single‐centre observational study. Children aged 3–18 years were measured for weight and height at home using guidance provided to parents on proper measurements techniques before subsequent professional re‐evaluation at our endocrine institution clinic. The two sets of measurements were compared and analysed according to various clinical parameters.

Results

Height measurements at home and in the clinic were comparable (diff = 0.1 ± 1.3cm, p = 0.42) amongst the 107 children (mean age 10.2 ± 3.7, 56.1% males) participating in the study, except in overweight and obese children where they were significantly higher in the clinic (diff = 0.86 ± 1.48cm, p = 0.018). Weight and BMI were significantly higher in the clinic (diff = 0.45 ± 0.8kg and diff = 0.3 ± 0.6kg/m², p<0.001 and p<0.001, respectively).

Conclusions

Height measurements of children by their parents were accurate except in obese and overweight children, whereas weight measurements tended to be lower than in the clinic. With proper guidance, parents’ home measurements of height and weight are accurate and suitable for clinical decision‐making.

Fasting and postprandial trimethylamine N-oxide in sedentary and endurance-trained males following a short-term high-fat diet

Gut bacteria release trimethylamine (TMA) from dietary substrates. TMA is absorbed and is subsequently oxidized in the liver to produce trimethylamine N-oxide (TMAO). Plasma TMAO levels are positively correlated with risk for type 2 diabetes (T2D) and cardiovascular disease (CVD). High-fat diet (HFD) consumption has been reported to increase fasting and postprandial TMAO in sedentary individuals. However, whether the increase in TMAO with consumption of an HFD is observed in endurance-trained males is unknown. Healthy, sedentary (n = 17), and endurance-trained (n = 7) males consumed a 10-day eucaloric diet comprised of 55% carbohydrate, 30% total fat, and <10% saturated fat prior to baseline testing. Blood samples were obtained in a fasted state and for a 4-hour high-fat challenge (HFC) meal at baseline and then again following 5-day HFD (30% carbohydrate, 55% total fat, and 25% saturated fat). Plasma TMAO and TMA-moiety (choline, betaine, L-carnitine) concentrations were measured using isocratic ultraperformance liquid chromatography-tandem mass spectrometry. Age (23 ±3 vs. 22 ± 2 years) and body mass index (23.0 ± 3.0 vs. 23.5 ± 2.1 kg/m2 ) were similar (both p > 0.05) in the sedentary and endurance-trained group, respectively. VO2max was significantly higher in the endurance-trained compared with sedentary males (56.7 ± 8.2 vs. 39.9 ± 6.0 ml/kg/min). Neither the HFC nor the HFD evoked a detectable change in plasma TMAO (p > 0.05) in either group. Future studies are needed to identify the effects of endurance training on TMAO production.

Weight Bias 2.0: The Effect of Perceived Weight Change on Performance Evaluation and the Moderating Role of Anti-fat Bias

Overweight employees are viewed as lazy, slow, inactive, and even incapable. Even if such attributes are false, this perspective can seriously undermine others' evaluation of their work performance. The current study explores a broader phenomenon of weight bias that has an effect on weight change. In a longitudinal study with a time lag of 6 months, we surveyed 226 supervisor-employee dyads. We found supervisor perceptions of employee weight change notably altered their evaluation of the employee performance from Time 1, especially following low vs. high Time-1 performance evaluation. Meanwhile, the moderating effects among different levels of supervisor anti-fat bias functioned as boundary conditions for such performance evaluation alteration. In particular, the interaction between the Time-1 performance evaluation and the impact of supervisor perception of employee weight change on the Time-2 performance evaluation was significant only if supervisors held a stronger anti-fat bias.

An objective measure of energy intake using the principle of energy balance

BACKGROUND

The measurement of energy intake is central to the understanding of energy balance and predicting changes in body weight. Until recently, the most commonly used methods of assessing intake were self-reported diet recalls, diet diaries, or food-frequency questionnaires. These methods, however, are subject to systematic biases and are often inaccurate.

AIM

Review the validations and applications of an expenditure/balance method for measuring energy intake.

METHODS

Review the literature regarding the theory and practice of objectively measuring energy intake based on the principle of energy balance i.e., energy intake is calculated from the measured total energy expenditure plus the change in body energy stores (ES). The attainable precision is modeled and compared with the accuracy and precision of validations against known energy intake.

RESULTS

Measurement of energy intake, calculated in this way, is accurate to within 2% and has a precision of 4-37% depending on the expenditure and body composition methods used and the time interval between measures. Applications of this expenditure/balance (EB) method have provided novel data on the compliance to dietary restriction and its association with physical activity interventions, and the effects of bariatric surgery on energy intake and weight gain. Practical limitations to this method, however, include cost and limited access to the analyses required by the DLW method.

CONCLUSION

The EB method of objectively measuring energy intake is objective, accurate, and reasonably precise. It is practical for moderate-sized studies.

The effect of subjective sleep latency on BMI of medical interns during and before COVID-19 pandemic

OBJECTIVES

Longer subjective sleep latency and eveningness chronotype are associated with higher BMI. Moreover, COVID-19 lockdown changes have been associated with increased BMI. The aim of this study was to investigate the effect of subjective sleep parameters on BMI of medical interns during and before COVID-19 pandemic.

MATERIAL AND METHODS

This cross-sectional study was performed among medical interns. Bedtime, sleep latency, waking time, sleep duration, and reduced morningness-eveningness scores were evaluated.

RESULTS

There was significant difference between bedtime before (00:11±50) and during (01:10±85) the pandemic in females (p<0.001). The mean circadian score before and during the pandemic showed significant decrease in females (p=0.011). The correlation between BMI with subjective sleep latency in females before and during the pandemic ((r=0.439, p=0.017), (r=0.422, p=0.014)) was significant.

CONCLUSION

COVID-19 pandemic was associated with a change toward nocturnal life among female medical interns. Subjective sleep latency was significantly correlated with BMI in females.

Hair Cortisol Concentration, Weight Loss Maintenance and Body Weight Variability: A Prospective Study Based on Data From the European NoHoW Trial

Several cross-sectional studies have shown hair cortisol concentration to be associated with adiposity, but the relationship between hair cortisol concentration and longitudinal changes in measures of adiposity are largely unknown. We included 786 adults from the NoHoW trial, who had achieved a successful weight loss of ≥5% and had a body mass index of ≥25 kg/m² prior to losing weight. Hair cortisol concentration (pg/mg hair) was measured at baseline and after 12 months. Body weight and body fat percentage were measured at baseline, 6-month, 12-month and 18-month visits. Participants weighed themselves at home ≥2 weekly using a Wi-Fi scale for the 18-month study duration, from which body weight variability was estimated using linear and non-linear approaches. Regression models were conducted to examine log hair cortisol concentration and change in log hair cortisol concentration as predictors of changes in body weight, change in body fat percentage and body weight variability. After adjustment for lifestyle and demographic factors, no associations between baseline log hair cortisol concentration and outcome measures were observed. Similar results were seen when analysing the association between 12-month concurrent development in log hair cortisol concentration and outcomes. However, an initial 12-month increase in log hair cortisol concentration was associated with a higher subsequent body weight variability between month 12 and 18, based on deviations from a nonlinear trend (β: 0.02% per unit increase in log hair cortisol concentration [95% CI: 0.00, 0.04]; P=0.016). Our data suggest that an association between hair cortisol concentration and subsequent change in body weight or body fat percentage is absent or marginal, but that an increase in hair cortisol concentration during a 12-month weight loss maintenance effort may predict a slightly higher subsequent 6-months body weight variability.

CLINICAL TRIAL REGISTRATION

ISRCTN registry, identifier ISRCTN88405328.

The impact of early body-weight variability on long-term weight maintenance: exploratory results from the NoHoW weight-loss maintenance intervention

BACKGROUND

Weight-loss programmes often achieve short-term success though subsequent weight regain is common. The ability to identify predictive factors of regain early in the weight maintenance phase is crucial.

OBJECTIVE

To investigate the associations between short-term weight variability and long-term weight outcomes in individuals engaged in a weight-loss maintenance intervention.

METHODS

The study was a secondary analysis from The NoHoW trial, an 18-month weight maintenance intervention in individuals who recently lost ≥5% body weight. Eligible participants (n = 715, 64% women, BMI = 29.2 (SD 5.0) kg/m², age = 45.8 (SD 11.5) years) provided body-weight data by smart scale (Fitbit Aria 2) over 18 months. Variability in body weight was calculated by linear and non-linear methods over the first 6, 9 and 12 weeks. These estimates were used to predict percentage weight change at 6, 12, and 18 months using both crude and adjusted multiple linear regression models.

RESULTS

Greater non-linear weight variability over the first 6, 9 and 12 weeks was associated with increased subsequent weight in all comparisons; as was greater linear weight variability measured over 12 weeks (up to AdjR² = 4.7%). Following adjustment, 6-week weight variability did not predict weight change in any model, though greater 9-week weight variability by non-linear methods was associated with increased body-weight change at 12 (∆AdjR² = 1.2%) and 18 months (∆AdjR² = 1.3%) and by linear methods at 18 months (∆AdjR² = 1.1%). Greater non-linear weight variability measured over 12 weeks was associated with increased weight at 12 (∆AdjR² = 1.4%) and 18 (∆AdjR² = 2.2%) months; and 12-week linear variability was associated with increased weight at 12 (∆AdjR² = 2.1%) and 18 (∆AdjR² = 3.6%) months.

CONCLUSION

Body-weight variability over the first 9 and 12 weeks of a weight-loss maintenance intervention weakly predicted increased weight at 12 and 18 months. These results suggest a potentially important role in continuously measuring body weight and estimating weight variability.

Short-term weight change and live birth among women with unexplained infertility and polycystic ovary syndrome undergoing ovulation induction

OBJECTIVE

To determine if short-term weight change among women with unexplained infertility (UI) and polycystic ovary syndrome (PCOS) undergoing ovulation induction is associated with live birth.

DESIGN

Secondary analysis of randomized trials.

SETTING

Multicenter fertility trial sites.

PATIENT(S)

A total of 900 women with UI and 750 women with PCOS.

MAIN OUTCOME MEASURE(S)

Live birth.

INTERVENTION(S)

Weight assessment at enrollment and start of up to 4-5 cycles of clomiphene, letrozole, or gonadotropins and intrauterine insemination for women with UI and clomiphene or letrozole with regular intercourse for women with PCOS.

RESULT(S)

Weight data were available for 856 women with UI and 697 women with PCOS. Mean weight change was -0.2 ± 0.3 kg among women with UI and +2.2 ± 0.2 kg among women with PCOS and did not differ based on treatment allocation. There were 115 women with PCOS (16.4%) who gained ≥3 kg. Increased body mass index and three or more cycles were associated with weight gain in women with PCOS. There was no difference in live birth rate among women with PCOS and ≥3 kg weight gain and women with PCOS who did not gain weight.

CONCLUSION(S)

Women with PCOS gained an average of 2.2 kg regardless of the medication received, whereas women with UI experienced no short-term weight change during ovulation induction. Weight gain in women with PCOS was not associated with live birth rate.

Change in eating pattern as a contributor to energy intake and weight gain during the winter holiday period in obese adults

Background/Objectives:

The winter holiday season in the US, which spans mid-November to mid-January, contributes to over half of annual body weight gain. Although self-reported data has linked this weight change to both increased energy intake and reduced physical activity, objective techniques have never been used and thus the actual cause of holiday weight gain is controversial. Here, we aimed to determine changes in components of energy balance leading to the holiday weight gain.

Methods:

Body weight change was compared between the pre-holiday (mid-September to mid-November) and the holiday period (mid-November to early January). Total energy expenditure (TEE) was measured using doubly labeled water during holiday time (early to mid-December). Subjective (ratings) and physiological (appetite-regulating hormones) measures of appetite, eating-away-from-home frequency, and incentive salience of food pictures were also evaluated.

Results:

In 23 obese adults (87% female), body weight change during the holidays (0.41 ± 0.42 kg) was significantly higher (P=0.02) than the body weight change during the pre-holiday period (−0.86 kg ± 0.42 kg). The TEE was unchanged during the two periods, suggesting no role of energy expenditure on weight gain. However, participants reported lower satisfaction after a meal pre-load which was significantly correlated with increased body weight during the holiday period. An increase in number of episodes of eating at sit-down restaurants was also reported during that period. Overall, these changing behaviors were supported by a non-significant increase in energy intake (+80 kcal/day, P=0.07) observed during the study holiday period.

Conclusion:

We conclude that a decrease in energy expenditure does not result in the weight increase, but that an increase in food intake is the more likely cause. Our data imply that compromised internal satiety mechanisms in presence of external food cues and diet related behavioral variables during the holidays may influence this weight gain.

A systematic review of the methodology used to study weight change among young adults attending college

INTRODUCTION

Young adulthood is a sensitive developmental period that is high-risk for weight gain. Ample research has focused on weight gain among college students; however meta-analyses report <2 kg pooled estimates of weight gain, which is in the range of normal weight fluctuation, and there is disagreement in the literature regarding common predictors of weight gain. These limitations pose a major barrier to targeted obesity prevention efforts. The present study reviewed the literature assessing college weight gain with a focus on three methodological factors that could contribute to variability in the literature: 1) use of an evidence-supported definition of weight gain (>2 kg or ≥3%); 2) weight measurement protocols; and 3) including weight/BMI in analyses of predictors of weight change.

METHODS

Three databases were systematically searched. Studies were included in the review if the primary goal was to determine magnitude of weight change and/or test predictors of weight change during the academic year, and they reported weight at 2+ time points.

RESULTS

A total of 81 studies were included in the review. Most studies (90%; 73/81) did not use an evidence-supported definition of weight gain. Studies that used an evidence-supported definition reported estimates of gain among students who gained weight to be beyond the range of normal weight fluctuation (4.0-7.5 kg), and occurred in a subset (<32%) of participants. Studies that did not use an evidence-supported definition reported weight gain to be 2.0-4.5 kg, and occurred in the majority >50% of students. Most studies that measured height and weight (71%; 42/59) did not use a fasting protocol and the majority (63%; 37/59) did not conduct measurements at the same time of day. A higher percentage of studies that used a standardized measurement protocol reported weight change >2 kg (44% vs 20%). A lower percentage of studies that used a standardized measurement protocol had substantial variability in weight change estimates (50% vs 69%). The majority of studies that tested predictors of weight gain (74%; 42/57) included weight/BMI as a covariate in analyses.

CONCLUSIONS

The body of literature examining weight change among college students suffers from limitations that may have contributed to overestimations in the percent of students who gain weight, and simultaneous underestimations of the magnitude of weight gain among those who gain weight. Weight gain may be limited to approximately 30% of students in a sample, and weight gain among this subset of students may be substantial (>4 kg). Going forward, use of both an evidence-supported weight gain definition and fasting measurement protocol will likely enhance accuracy in characterizing weight gain among college students, as well as improve researchers' ability to detect important predictors of weight gain.

Associations between the rate, amount, and composition of weight loss as predictors of spontaneous weight regain in adults achieving clinically significant weight loss: A systematic review and meta-regression

Weight regain following weight loss is common although little is known regarding the associations between amount, rate, and composition of weight loss and weight regain. Forty-three studies (52 groups; n = 2379) with longitudinal body composition measurements were identified in which weight loss (≥5%) and subsequent weight regain (≥2%) occurred. Data were synthesized for changes in weight and body composition. Meta-regression models were used to investigate associations between amount, rate, and composition of weight loss and weight regain. Individuals lost 10.9% of their body weight over 13 weeks composed of 19.6% fat-free mass, followed by a regain of 5.4% body weight over 44 weeks composed of 21.6% fat-free mass. Associations between the amount (P < 0.001) and rate (P = 0.049) of weight loss and their interaction (P = 0.042) with weight regain were observed. Fat-free mass (P = 0.017) and fat mass (P < 0.001) loss both predicted weight regain although the effect of fat-free mass was attenuated following adjustment. The amount (P < 0.001), but not the rate of weight loss (P = 0.150), was associated with fat-free mass loss. The amount and rate of weight loss were significant and interacting factors associated with weight regain. Loss of fat-free mass and fat mass explained greater variance in weight regain than weight loss alone.

The influence of exercise training dose on fasting acylated ghrelin concentration in older women

This study investigated if exercise dose affected acylated ghrelin response to exercise training, and how body weight or fat mass changes might affect the responses. Non-obese older women (n = 49) were randomly assigned to 4-month moderate-intensity aerobic exercise of one of two doses (8 or 14 kcal kg^-1 body weight weekly). Following exercise training, fasting acylated ghrelin concentrations changed differently between the two groups (p for group × time interaction = 0.050). It decreased in the moderate-dose (Cohen's d = 0.52, p = 0.019), but did not change in the low-dose exercise group. Adjustment for weight or fat changes did not affect these results. Therefore, exercise training dose can have specific effects on acylated ghrelin that are not dependent on weight or fat loss. However, whether the different acylated ghrelin changes are associated with differing degree of subsequent weight maintenance worth further investigation.

Comparing Interviewer-Administered and Web-Based Food Frequency Questionnaires to Predict Energy Requirements in Adults

Traditional food frequency questionnaires (FFQs) are influenced by systematic error, but web-based FFQ (WEB-FFQs) may mitigate this source of error. The objective of this study was to compare the accuracy of interview-based and web-based FFQs to assess energy requirements (mERs). The mER was measured in a series of controlled feeding trials in which participants daily received all foods and caloric drinks to maintain stable body weight over 4 to 6 weeks. FFQs assessing dietary intakes and hence mean energy intake were either interviewer-administered by a registered dietitian (IA-FFQ, n = 127; control method) or self-administered using a web-based platform (WEB-FFQ, n = 200; test method), on a single occasion. Comparison between self-reported energy intake and mER revealed significant under-reporting with the IA-FFQ (-9.5%; 95% CI, -12.7 to -6.1) and with the WEB-FFQ (-11.0%; 95% CI, -15.4 to -6.4), but to a similar extent between FFQs (p = 0.62). However, a greater proportion of individuals were considered as accurate reporters of energy intake using the IA-FFQ compared with the WEB-FFQ (67.7% vs. 48.0%, respectively), while the prevalence of over-reporting was lower with the IA-FFQ than with the WEB-FFQ (6.3% vs. 17.5%, respectively). These results suggest less accurate prediction of true energy intake by a self-administered WEB-FFQ than with an IA-FFQ.

Energy Deficit Required for Rapid Weight Loss in Elite Collegiate Wrestlers

To determine energy density for rapid weight loss (RWL) of weight-classified sports, eight male elite wrestlers were instructed to lose 6% of body mass (BM) within 53 h. Energy deficit during the RWL was calculated by subtracting total energy expenditure (TEE) determined using the doubly labeled water method (DLW) from energy intake (EI) assessed with diet records. It was also estimated from body composition change estimated with the four-component model (4C) and other conventional methods. BM decreased significantly by 4.7 &plusmn; 0.5 kg (6.4 &plusmn; 0.5%). Total body water loss was the major component of the BM loss (71.0 &plusmn; 7.6%). TEE was 9446 &plusmn; 1422 kcal, and EI was 2366 &plusmn; 1184 kcal during the RWL of 53-h; therefore, the energy deficit was 7080 &plusmn; 1525 kcal. Thus, energy density was 1507 &plusmn; 279 kcal/kg ∆BM during the RWL, comparable with values obtained using the 4C, three-component model, dual energy X-ray absorptiometry, and stable isotope dilution. Energy density for RWL of wrestlers is lower than that commonly used (7400 or 7700 kcal/kg &Delta;BM). Although RWL is not recommended, we propose that commonly practiced extreme energy restriction such as 7400 or 7700 kcal/kg &Delta;BM during RWL appears to be meaningless.

Composition of two-week change in body weight under unrestricted free-living conditions

The composition of weight change has a large impact on energy balance calculations. Composition of long-term weight change interventions is well-documented, but information on short-term weight change under unrestricted free-living conditions is limited. The composition and energy density of the changes in body weight during 2-week free-living conditions were analyzed in adults from two cohorts: cohort 1 (n = 24) included participants from the reproducibility subset of the Observing Protein and Energy Nutrition study; cohort 2 (n = 22) included participants who were studied under free-living conditions in an ongoing study in the Chicago area. Change in body weight, total body water (TBW) by stable isotope dilution (cohort 1), and fat mass (FM) and fat-free mass (FFM) by serial DXA (cohort 2) were measured. To determine the fractional composition of the change in body weight we analyzed the linear associations between changes in body weight and changes in body composition. In the combined dataset, the average change in body weight (0.26 ± 1.2 kg) was consistent with being in energy balance. Average change in body weight was associated with the change in TBW (P < 0.0001) in cohort 1 and the change in FFM (P = 0.0002) in cohort 2. A unit change in body weight was composed of 84% change in FFM in the combined dataset indicating that 2-week fluctuation in body weight is largely composed of FFM The energy density of 1-3 kg short-term changes in body weight averaged 2380 kcal/kg.

Lifestyle Intervention Program for Amelioration of Dysmetabolism in Overweight Women

Overweight and obesity, a cluster of multiple risk factors for atherosclerosis such as elevated blood pressure, elevated glucose level, and dyslipidemia, increase the risk of all-cause mortality and cardiovascular morbidity and mortality. Physical activity and a proper diet are essential preventive measures. The aim of the study was to evaluate the effects of a two-month intervention program consisting of a low-caloric diet (1,500 kcal) and increased physical activity on the anthropometric parameters, body composition, resting metabolic rate, and maximum oxygen uptake. The study was conducted in 22 women aged 20-38 with diagnosed overweight or obesity. We found that after completing the eight-week-long intervention program, there were significant changes in body composition, consisting of a smaller proportion of body fat and increased lean body mass. Further, we observed a decrease in body weight by 4.3 ± 2.5 kg (p < 0.01), a reduction in waist and hip circumference of 2.6 ± 4.5 cm (p < 0.01) and 4.4 ± 2.9 cm (p < 0.01), respectively, and an increase in maximum oxygen uptake by about 5.2 ± 8.4 ml/kg/min (p < 0.01). We conclude that the intervention program consisting of counseling on diet and physical activity may be highly motivational for patients with excess body weight and care givers should give it a try before commencing more aggressive psychopharmacological therapies.