A low-glucose eating pattern is associated with improvements in glycemic variability among women at risk for postmenopausal breast cancer: an exploratory analysis

Background

High glycemic variability (GV) is a biomarker of cancer risk, even in the absence of diabetes. The emerging concept of chrononutrition suggests that modifying meal timing can favorably impact metabolic risk factors linked to diet-related chronic disease, including breast cancer. Here, we examined the potential of eating when glucose levels are near personalized fasting thresholds (low-glucose eating, LGE), a novel form of timed-eating, to reduce GV in women without diabetes, who are at risk for postmenopausal breast cancer.

Methods

In this exploratory analysis of our 16-week weight loss randomized controlled trial, we included 17 non-Hispanic, white, postmenopausal women (average age = 60.7 ± 5.8 years, BMI = 34.5 ± 6.1 kg/m2, HbA1c = 5.7 ± 0.3%). Participants were those who, as part of the parent study, provided 3-7 days of blinded, continuous glucose monitoring data and image-assisted, timestamped food records at weeks 0 and 16. Pearson's correlation and multivariate regression were used to assess associations between LGE and GV, controlling for concurrent weight changes.

Results

Increases in LGE were associated with multiple unfavorable measures of GV including reductions in CGM glucose mean, CONGA, LI, J-Index, HBGI, ADDR, and time spent in a severe GV pattern (r = -0.81 to -0.49; ps < 0.044) and with increases in favorable measures of GV including M-value and LBGI (r = 0.59, 0.62; ps < 0.013). These associations remained significant after adjusting for weight changes.

Conclusion

Low-glucose eating is associated with improvements in glycemic variability, independent of concurrent weight reductions, suggesting it may be beneficial for GV-related disease prevention. Further research in a larger, more diverse sample with poor metabolic health is warranted.Clinical trial registration: ClinicalTrials.gov, NCT03546972.

Use of Biological Feedback as a Health Behavior Change Technique in Adults: Scoping Review

BACKGROUND

Recent advancements in personal biosensing technology support the shift from standardized to personalized health interventions, whereby biological data are used to motivate health behavior change. However, the implementation of interventions using biological feedback as a behavior change technique has not been comprehensively explored.

OBJECTIVE

The purpose of this review was to (1) map the domains of research where biological feedback has been used as a behavior change technique and (2) describe how it is implemented in behavior change interventions for adults.

METHODS

A comprehensive systematic search strategy was used to query 5 electronic databases (Ovid MEDLINE, Elsevier Embase, Cochrane Central Register of Controlled Trials, EBSCOhost PsycINFO, and ProQuest Dissertations & Theses Global) in June 2021. Eligible studies were primary analyses of randomized controlled trials (RCTs) in adults that incorporated biological feedback as a behavior change technique. DistillerSR was used to manage the literature search and review.

RESULTS

After removing 49,500 duplicates, 50,287 articles were screened and 767 articles were included. The earliest RCT was published in 1972 with a notable increase in publications after 2000. Biological feedback was most used in RCTs aimed at preventing or managing diabetes (n=233, 30.4%), cardiovascular disease (n=175, 22.8%), and obesity (n=115, 15%). Feedback was often given on multiple biomarkers and targeted multiple health behaviors. The most common biomarkers used were anthropometric measures (n=297, 38.7%), blood pressure (n=238, 31%), and glucose (n=227, 29.6%). The most targeted behaviors were diet (n=472, 61.5%), physical activity (n=417, 54.4%), and smoking reduction (n=154, 20.1%). The frequency and type of communication by which biological feedback was provided varied by the method of biomarker measurement. Of the 493 (64.3%) studies where participants self-measured their biomarker, 476 (96.6%) received feedback multiple times over the intervention and 468 (94.9%) received feedback through a biosensing device.

CONCLUSIONS

Biological feedback is increasingly being used to motivate behavior change, particularly where relevant biomarkers can be readily assessed. Yet, the methods by which biological feedback is operationalized in intervention research varied, and its effectiveness remains unclear. This scoping review serves as the foundation for developing a guiding framework for effectively implementing biological feedback as a behavior change technique.

TRIAL REGISTRATION

Open Science Framework Registries; https://doi.org/10.17605/OSF.IO/YP5WAd.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-10.2196/32579.

Exploring the Impact of Dawn Phenomenon on Glucose-Guided Eating Thresholds in Individuals With Type 2 Diabetes Using Continuous Glucose Monitoring: Observational Study

BACKGROUND

Glucose-guided eating (GGE) improves metabolic markers of chronic disease risk, including insulin resistance, in adults without diabetes. GGE is a timed eating paradigm that relies on experiencing feelings of hunger and having a preprandial glucose level below a personalized threshold computed from 2 consecutive morning fasting glucose levels. The dawn phenomenon (DP), which results in elevated morning preprandial glucose levels, could cause typically derived GGE thresholds to be unacceptable or ineffective among people with type 2 diabetes (T2DM).

OBJECTIVE

The aim of this study is to quantify the incidence and day-to-day variability in the magnitude of DP and examine its effect on morning preprandial glucose levels as a preliminary test of the feasibility of GGE in adults with T2DM.

METHODS

Study participants wore a single-blinded Dexcom G6 Pro continuous glucose monitoring (CGM) system for up to 10 days. First and last eating times and any overnight eating were reported using daily surveys over the study duration. DP was expressed as a dichotomous variable at the day level (DP day vs non-DP day) and as a continuous variable reflecting the percent of days DP was experienced on a valid day. A valid day was defined as having no reported overnight eating (between midnight and 6 AM). ∂ Glucose was computed as the difference in nocturnal glucose nadir (between midnight and 6 AM) to morning preprandial glucose levels. ∂ Glucose ≥20 mg/dL constituted a DP day. Using multilevel modeling, we examined the between- and within-person effects of DP on morning preprandial glucose and the effect of evening eating times on DP.

RESULTS

In total, 21 adults (59% female; 13/21, 62%) with non-insulin-treated T2DM wore a CGM for an average of 10.5 (SD 1.1) days. Twenty out of 21 participants (95%) experienced DP for at least 1 day, with an average of 51% of days (SD 27.2; range 0%-100%). The mean ∂ glucose was 23.7 (SD 13.2) mg/dL. People who experience DP more frequently had a morning preprandial glucose level that was 54.1 (95% CI 17.0-83.9; P<.001) mg/dL higher than those who experienced DP less frequently. For within-person effect, morning preprandial glucose levels were 12.1 (95% CI 6.3-17.8; P=.008) mg/dL higher on a DP day than on a non-DP day. The association between ∂ glucose and preprandial glucose levels was 0.50 (95% CI 0.37-0.60; P<.001). There was no effect of the last eating time on DP.

CONCLUSIONS

DP was experienced by most study participants regardless of last eating times. The magnitude of the within-person effect of DP on morning preprandial glucose levels was meaningful in the context of GGE. Alternative approaches for determining acceptable and effective GGE thresholds for people with T2DM should be explored and evaluated.

Emotional Eating as a Mediator in the Relationship between Dietary Restraint and Body Weight

This study aimed to assess the relationships between routine and compensatory restraints and body mass index (BMI), as well as to explore the mediating role of emotional and external eating in the relationships between routine and compensatory restraints and BMI. Chinese adults aged ≥18 years with different weight statuses were invited to fill out an online questionnaire. Routine and compensatory restraints and emotional and external eating were assessed using the validated 13-item Chinese version of the Weight-Related Eating Questionnaire. Mediation analyses tested the mediation effects of emotional and external eating on the relationship between routine and compensatory restraints and BMI. In total, 949 participants (26.4% male) responded to the survey (mean age = 33 years, standard deviation (SD) = 14, mean BMI = 22.0 kg/m², SD = 3.8). The mean routine restraint score was higher in the overweight/obese group (mean ± SD = 2.13 ± 0.76, p < 0.001) than in the normal weight (2.08 ± 0.89) and underweight (1.72 ± 0.94) groups. However, the normal weight group scored higher in compensatory restraint (2.88 ± 1.03, p = 0.021) than the overweight/obese (2.75 ± 0.93) and underweight (2.62 ± 1.04) groups. Routine restraint was related to higher BMI both directly (β = 0.07, p = 0.02) and indirectly through emotional eating (β = 0.04, 95% confidence interval (CI) = 0.03, 0.07). Compensatory restraint was only indirectly related to higher BMI through emotional eating (β = 0.04, 95% CI = 0.03, 0.07).

A qualitative study to explore the acceptability and usefulness of personalized biofeedback to motivate physical activity in cancer survivors

Objective

Many cancer survivors do not meet recommended levels of exercise, despite the benefits physical activity offers. This study aimed to understand experiences of insufficiently active overweight/obese breast or colorectal cancer survivors, in efforts to (1) examine regular physical activity barriers, and (2) determine perceptions and acceptability of a remotely delivered physical activity intervention utilizing wearable sensors and personalized feedback messages.

Methods

In-person and virtual small group interviews were conducted engaging overweight/obese cancer survivors (n = 16, 94% female, 94% breast cancer survivors) in discussions resulting in 314 pages of transcribed data analyzed by multiple coders.

Results

All participants expressed needing to increase physical activity, identifying lack of motivation centering on survivorship experiences and symptom management as the most salient barrier. They indicated familiarity with activity trackers (i.e., Fitbit) and expressed interest in biosensors (i.e., continuous glucose monitors [CGMs]) as CGMs show biological metrics in real-time. Participants reported (1) personalized feedback messages can improve motivation and accountability; (2) CGM acceptability is high given survivors’ medical history; and (3) glucose data is a relevant health indicator and they appreciated integrated messages (between Fitbit and CGM) in demonstrating how behaviors immediately affect one's body.

Conclusions

This study supports the use of wearable biosensors and m-health interventions to promote physical activity in cancer survivors. Glucose-based biofeedback provides relevant and motivating information for cancer survivors regarding their daily activity levels by demonstrating the immediate effects of physical activity. Integrating biofeedback into physical activity interventions could be an effective behavioral change strategy to promote a healthy lifestyle in cancer survivors.

Using wearable biological sensors to provide personalized feedback to motivate behavioral changes: Study protocol for a randomized controlled physical activity intervention in cancer survivors (Project KNOWN)

Regular physical activity reduces the progression of several cancers and offers physical and mental health benefits for cancer survivors. However, many cancer survivors are not sufficiently active to achieve these health benefits. Possible biological mechanisms through which physical activity could affect cancer progression include reduced systemic inflammation and positive changes in metabolic markers. Chronic and acute hyperglycemia could have downstream effects on cell proliferation and tumorigenesis. One novel strategy to motivate cancer survivors to be more active is to provide personalized biological-based feedback that demonstrates the immediate positive impact of physical activity. Continuous glucose monitors (CGMs) have been used to demonstrate the acute beneficial effects of physical activity on insulin sensitivity and glucose metabolisms in controlled lab settings. Using personal data from CGMs to illustrate the immediate impact of physical activity on glucose patterns could be particularly relevant for cancer survivors because they are at a higher risk for developing type 2 diabetes (T2D). As a pilot project, this study aims to (1) test the preliminary effect of a remotely delivered physical activity intervention that incorporates personalized biological-based feedback on daily physical activity levels, and (2) explore the association between daily glucose patterns and cancer-related insulin pathway and inflammatory biomarkers in cancer survivors who are at high risk for T2D. We will recruit 50 insufficiently active, post-treatment cancer survivors who are at elevated risk for T2D. Participants will be randomly assigned into (1) a group that receives personalized biological feedback related to physical activity behaviors; and (2) a control group that receives standard educational material. The feasibility and preliminary efficacy of this wearable sensor-based, biofeedback-enhanced 12-week physical activity intervention will be evaluated. Data from this study will support the further refinement and enhancement of a more comprehensive remotely delivered physical activity intervention that targets cancer survivors.

Trial registration: ClinicalTrials.gov Identifier: NCT05490641.

Interpreting Clinical Trials With Omega-3 Supplements in the Context of Ancestry and FADS Genetic Variation

Human diets in developed countries such as the US have changed dramatically over the past 75 years, leading to increased obesity, inflammation, and cardiometabolic dysfunction. Evidence over the past decade indicates that the interaction of genetic variation with changes in the intake of 18-carbon essential dietary omega-6 (n-6) and omega-3 (n-3) polyunsaturated fatty acids (PUFA), linoleic acid (LA) and α-linolenic acid (ALA), respectively, has impacted numerous molecular and clinical phenotypes. Interactions are particularly relevant with the FADS1 and FADS2 genes, which encode key fatty acid desaturases in the pathway that converts LA and ALA to their long chain (≥20 carbons), highly unsaturated fatty acid (HUFA) counterparts. These gene by nutrient interactions affect the levels and balance of n-6 and n-3 HUFA that in turn are converted to a wide array of lipids with signaling roles, including eicosanoids, docosanoids, other oxylipins and endocannabinoids. With few exceptions, n-6 HUFA are precursors of pro-inflammatory/pro-thrombotic signaling lipids, and n-3 HUFA are generally anti-inflammatory/anti-thrombotic. We and others have demonstrated that African ancestry populations have much higher frequencies (vs. European-, Asian- or indigenous Americas-ancestry populations) of a FADS “derived” haplotype that is associated with the efficient conversion of high levels of dietary n-6 PUFA to pro-inflammatory n-6 HUFA. By contrast, an “ancestral” haplotype, carrying alleles associated with a limited capacity to synthesize HUFA, which can lead to n-3 HUFA deficiency, is found at high frequency in certain Hispanic populations and is nearly fixed in several indigenous populations from the Americas. Based on these observations, a focused secondary subgroup analysis of the VITAL n-3 HUFA supplementation trial stratifying the data based on self-reported ancestry revealed that African Americans may benefit from n-3 HUFA supplementation, and both ancestry and FADS variability should be factored into future clinical trials design.

Using Biological Feedback to Promote Health Behavior Change in Adults: Protocol for a Scoping Review

Background

Many health conditions can be prevented, managed, or improved through behavioral interventions. As a component of health behavior change interventions, biological feedback is of particular interest given recent advances in wearable biosensing technology, digital health apps, and personalized health and wellness. Nevertheless, there is a paucity of literature to guide the design and implementation of interventions that incorporate biological feedback to motivate health behavior change.

Objective

The goal of this scoping review is to deeply explore the use of biological feedback as a component of health behavior change interventions that target adults. The objectives of the review include (1) mapping the domains of research that incorporate biological feedback and (2) describing the operational characteristics of using biological feedback in the context of health behavior change.

Methods

A comprehensive list of search terms was developed to capture studies from a wide range of domains. The studies to be included are randomized controlled trials published as primary research articles, theses, or dissertations targeting adults 18 years and older, who use biological feedback to change a health-related behavior. The following electronic databases were searched: Ovid MEDLINE, Embase, Cochrane Central Register of Controlled Trials, EBSCOhost, PsycINFO, and ProQuest Dissertations & Theses Global. The screening and data extraction process will be guided by the Joanna Briggs Institute Manual for Evidence Synthesis and conducted by trained reviewers.

Results

Database searches were completed in June 2021. A total of 50,459 unique records were returned after the removal of 48,634 duplicate records. The scoping review is planned for completion in 2022.

Conclusions

To our knowledge, this will be the first scoping review to map the literature that uses biological feedback as a component of health behavior change interventions targeting adults. The findings will be used to develop a framework to guide the design and implementation of future health behavior change interventions that incorporate biological feedback.

Trial Registration

OSF Registries OSF.IO/YP5WA; https://osf.io/yp5wa

International Registered Report Identifier (IRRID)

DERR1-10.2196/32579

A Low-Glucose Eating Pattern Improves Biomarkers of Postmenopausal Breast Cancer Risk: An Exploratory Secondary Analysis of a Randomized Feasibility Trial

Postmenopausal breast cancer is the most common obesity-related cancer death among women in the U.S. Insulin resistance, which worsens in the setting of obesity, is associated with higher breast cancer incidence and mortality. Maladaptive eating patterns driving insulin resistance represent a key modifiable risk factor for breast cancer. Emerging evidence suggests that time-restricted feeding paradigms (TRF) improve cancer-related metabolic risk factors; however, more flexible approaches could be more feasible and effective. In this exploratory, secondary analysis, we identified participants following a low-glucose eating pattern (LGEP), defined as consuming energy when glucose levels are at or below average fasting levels, as an alternative to TRF. Results show that following an LGEP regimen for at least 40% of reported eating events improves insulin resistance (HOMA-IR) and other cancer-related serum biomarkers. The magnitude of serum biomarkers changes observed here has previously been shown to favorably modulate benign breast tissue in women with overweight and obesity who are at risk for postmenopausal breast cancer. By comparison, the observed effects of LGEP were similar to results from previously published TRF studies in similar populations. These preliminary findings support further testing of LGEP as an alternative to TRF and a postmenopausal breast cancer prevention strategy. However, results should be interpreted with caution, given the exploratory nature of analyses.

Hunger Training as a self-regulation strategy in a comprehensive weight loss program for breast cancer prevention: a randomized feasibility study

Weight losses >10% favorably modulate biomarkers of breast cancer risk but are not typically achieved by comprehensive weight loss programs, including the Diabetes Prevention Program (DPP). Combining the DPP with Hunger Training (HT), an evidence-based self-regulation strategy that uses self-monitored glucose levels to guide meal timing, has potential to enhance weight losses and cancer-related biomarkers, if proven feasible. This 2-arm RCT examined the feasibility of adding HT to the DPP and explored effects on weight and metabolic and breast cancer risk biomarkers. Fifty postmenopausal women (BMI > 27 kg/m2) at risk of breast cancer were randomized to the DPP+HT or DPP-only arm. Both arms followed a 16-week version of the DPP delivered weekly by a trained registered dietitian. Those in the DPP+HT also wore a continuous glucose monitor during weeks 4-6 of the program. Feasibility criteria were accrual rates > 50%, retention rates > 80%, and adherence to the HT protocol >75%. All a priori feasibility criteria were achieved. The accrual rate was 67%; retention rate was 81%; and adherence to HT was 90%. Weight losses and BMI reductions were significant over time as were changes in metabolic and breast cancer risk biomarkers but did not vary by group. This trial demonstrated that HT was feasible to add to comprehensive weight management program targeted towards postmenopausal women at high risk of breast cancer, though upon preliminary examination it does not appear to enhance weight loss or metabolic changes.

Satiety does not affect neuroaffective electrophysiological responses to food-related or emotional visual cues

Continuing to eat even when full leads to excessive calorie consumption and obesity. Thus, understanding brain responses to food cues when satiated has important implications for weight control interventions. We used the late positive potential (LPP, a component of the event-related potentials (ERP) indexing motivational relevance) to determine the extent to which satiety affects brain responses to images of highly palatable foods (high-fat, high-sugar), high and low motivationally relevant (pleasant, unpleasant) and neutral stimuli in a sample of obese (body mass index [BMI] ≥ 30 kg/m2) and lean (BMI < 25 kg/m2) individuals. Satiated individuals (N = 55, 21 with BMI ≥ 30 kg/m2) were fed a nutritional drink prior to the experimental session and were individually matched with 55 unsatiated individuals who saw the same images during a passive viewing task. Satiety did not affect LPP response to food-related or motivationally relevant cues in either BMI < 25 kg/m2 or BMI ≥ 30 kg/m2 individuals (p = .6). Irrespective of satiety, all participants showed larger LPPs as a function of the images' motivational relevance. There were no differences in LPP amplitude between BMI < 25 kg/m2 and BMI ≥ 30 kg/m2 individuals for any picture category, including food. However, within-group comparisons showed that BMI < 25 kg/m2 individuals had larger LPPs to low motivationally relevant pleasant images than to food-related cues (p < .001); this difference was not significant for BMI ≥ 30 kg/m2 individuals. Although satiety does not affect LPP responses to food-related cues, these results highlight the importance of evaluating reactivity to food-related cues in relation to other motivationally relevant stimuli. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Internalizing symptoms modulate real-world affective response to sweet food and drinks in children

The purpose of the current study was to examine affective response to sweet foods and drinks as a function of children's internalizing symptoms using ecological momentary assessment (EMA). A sample of 192 8-12-year-old children completed a self-report measure of internalizing symptoms and EMA prompts of affect and food intake for eight days, excluding time at school. There was an interaction between sweet food intake and internalizing symptoms for positive affect and for sweet drink intake and internalizing symptoms for negative affect. Those low in internalizing symptoms had significantly lower positive affect after consumption of sweet foods compared to when they did not consume sweet foods whereas those higher in internalizing symptoms had slightly, but not significantly, higher positive affect after consumption of sweet foods. Those low in internalizing symptoms had significantly higher negtive affect after consumption of sweet drinks compared to when they did not consume sweet drinks whereas those higher in internalizing symptoms had slightly, but not significantly, lower negative affect after consumption of sweet drinks. Findings highlight the ways in which internalizing symptoms may modulate affective response to sweet foods and drinks.

Dietary inflammatory potential in relation to the gut microbiome: results from a cross-sectional study

Diet has direct and indirect effects on health through inflammation and the gut microbiome. We investigated total dietary inflammatory potential via the literature-derived index (Dietary Inflammatory Index (DII®)) with gut microbiota diversity, composition and function. In cancer-free patient volunteers initially approached at colonoscopy and healthy volunteers recruited from the medical centre community, we assessed 16S ribosomal DNA in all subjects who provided dietary assessments and stool samples (n 101) and the gut metagenome in a subset of patients with residual fasting blood samples (n 34). Associations of energy-adjusted DII scores with microbial diversity and composition were examined using linear regression, permutational multivariate ANOVA and linear discriminant analysis. Spearman correlation was used to evaluate associations of species and pathways with DII and circulating inflammatory markers. Across DII levels, α- and β-diversity did not significantly differ; however, Ruminococcus torques, Eubacterium nodatum, Acidaminococcus intestini and Clostridium leptum were more abundant in the most pro-inflammatory diet group, while Akkermansia muciniphila was enriched in the most anti-inflammatory diet group. With adjustment for age and BMI, R. torques, E. nodatum and A. intestini remained significantly associated with a more pro-inflammatory diet. In the metagenomic and fasting blood subset, A. intestini was correlated with circulating plasminogen activator inhibitor-1, a pro-inflammatory marker (rho = 0·40), but no associations remained significant upon correction for multiple testing. An index reflecting overall inflammatory potential of the diet was associated with specific microbes, but not overall diversity of the gut microbiome in our study. Findings from this preliminary study warrant further research in larger samples and prospective cohorts.

Abstract A17: An innovative physical activity intervention in overweight and obese adults using continuous glucose monitor

Introduction: Regular physical activity (PA) lowers the risk of endometrial, breast, and colorectal cancer. However, nearly half of American adults are not sufficiently active. The physical inactivity rate is even higher among the overweight and obese population, which, in combination with the unfavorable effect of excess body weight, puts this population at a greater risk for cancer. Advancements in wearable sensor technology provide opportunities for personalized approaches to increase motivation to be active. The current pilot study used continuous glucose monitors (CGM) to demonstrate the immediate, physiologic benefits of PA.

Methods: Insufficiently active (&lt;150 mins of moderate intensity PA per week) overweight and obese (body mass index &gt;= 25 kg/m2) adults (18-65 years old) without diabetes are being recruited to participate in this pilot intervention. Upon enrollment, participants go through a one-on-one PA education session that includes a discussion about the health benefits of recommended PA levels, demonstration of the acute effect of PA on daily glucose patterns using a web-based glucose simulator, calculation of personal heart rate zones for moderate intensity PA, and development of an exercise plan. After the education session, participants are given a Fitbit Alta HR wristband and are instructed to wear it over the next 10 days. Participants are also given a Freestyle Libre CGM, which consists of a sensor and a reader. The sensor is inserted into the back of the upper arm to collect interstitial glucose data every 15 minutes for 10 days after activation. The reader displays current glucose readings and a graph of the 8 previous hours of glucose data upon scanning the sensor. Participants are instructed to scan the sensor at least 4 times a day and are encouraged to achieve at least 150 minutes of moderate-intensity PA each week. At the end of the self-monitoring period, participants return their Fitbit and have their CGM sensor removed.

Results: Thus far, 10 of 20 participants have enrolled in and completed the study. These participants have been 100% female, 70% obese, and 20% Hispanic with a mean age of 41.5 (SD = 8.6) years old. On average, participants scanned their sensor 6 times each day and wore the Fitbit for all 10 days. On average, participants highly rated each component of the education session (on a 5-point scale) for improving their PA knowledge (mean = 4.4), increasing their PA motivation (mean = 4.4), and providing personally relevant information (mean = 4.6). Participants also reported a very positive experience wearing the CGM, with mean ratings (on a 5-point scale) of 4.8 for usability, 4.6 for convenience, 4.9 for value, 4.9 for relevance, and 4.7 for motivating.

Conclusion: These preliminary data suggest that using a CGM to motivate PA among nondiabetic adults is feasible and acceptable. Future research will be conducted to examine the effect a CGM-based PA intervention has on changing PA behavior.

Citation Format: Yue Liao, Christopher J. Miller, Diana L. Urbauer, Therese B. Bevers, Ernest Hawk, Karen M. Basen-Engquist, Susan M. Schembre. An innovative physical activity intervention in overweight and obese adults using continuous glucose monitor [abstract]. In: Proceedings of the AACR Special Conference on Modernizing Population Sciences in the Digital Age; 2019 Feb 19-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(9 Suppl):Abstract nr A17.

Diet, weight management, physical activity and Ovarian & Breast Cancer Risk in women with BRCA1/2 pathogenic Germline gene variants: systematic review

Introduction

Women with pathogenic germline gene variants in BRCA1 and/or BRCA2 are at increased risk of developing ovarian and breast cancer. While surgical and pharmacological approaches are effective for risk-reduction, it is unknown whether lifestyle approaches such as healthful dietary habits, weight management, and physical activity may also contribute to risk-reduction. We conducted a systematic review of evidence related to dietary habits, weight status/change, and physical activity on ovarian and breast cancer risk among women with BRCA1/2 pathogenic variants.

Methods

We searched Medline, EMBASE, CENTRAL, PubMed, and clinicaltrials.gov up to October 3, 2019. We identified 2775 records and included 21.

Results

There is limited evidence related to these factors and ovarian cancer risk. For breast cancer risk, evidence suggests higher diet quality, adulthood weight-loss of ≥10 pounds, and activity during adolescence and young-adulthood may be linked with decreased risk. Higher meat intake and higher daily energy intake may be linked with increased risk.

Conclusions

There is not enough evidence to suggest tailored recommendations for dietary habits or weight management among women with BRCA1/2 pathogenic variants compared to the general population for ovarian and breast cancer risk-reduction, and physical activity recommendations should remain the same.

Using Continuous Glucose Monitoring to Motivate Physical Activity in Overweight and Obese Adults: A Pilot Study

BACKGROUND

Regular physical activity (PA) is associated with a lower risk of several types of cancers. However, two-thirds of overweight/obese adults are not sufficiently active; this, in combination with the unfavorable effect of excess body weight, puts them at a greater risk for cancer. One reason that these individuals do not engage in enough PA may be their lack of motivation to change their current behavior due to the perception of putting in effort for possible future gain without obvious short-term benefits. There is a need for innovative ways to help individuals recognize the immediate health benefits of PA and thus increase their motivation.

METHODS

This pilot intervention tested a PA education module that included a one-on-one counseling session highlighting the acute effects of PA on glucose patterns, followed by a 10-day self-monitoring period with a continuous glucose monitor (CGM) and a Fitbit tracker. Participants rated the acceptability of the education module on a 5-point Likert scale and completed surveys assessing stages of change for motivational readiness.

RESULTS

Nineteen overweight/obese adults (84% female) completed the study. Participants gave high ratings to the counseling session for improving their PA-related knowledge (mean = 4.22), increasing motivation (mean = 4.29), and providing personally relevant information (mean = 4.35). The summary acceptability scores for the self-monitoring period were 4.46 for CGM and 4.51 for Fitbit. Participants reported a significant decrease in the precontemplation stage and an increase in the action stage (P < 0.05).

CONCLUSIONS

CGM is a feasible tool for PA interventions.

IMPACT

Information from CGM could be used as biological-based feedback to motivate PA.See all articles in this CEBP Focus section, "Modernizing Population Science."

The Association of Maternal Perceived Stress With Changes in Their Children's Healthy Eating Index (HEI-2010) Scores Over Time

BACKGROUND

Few studies have examined the role of maternal stress in relation to their children's dietary quality and its trajectory over time.

PURPOSE

The objective of this longitudinal study was to examine the effect of baseline maternal stress on the change in their 8- to 12-year-old children's dietary quality over 1 year.

METHODS

Mother-child dyads (N = 189) from the greater Los Angeles area participating in the Mothers' and their Children's Health (MATCH) study in 2014-2016 completed assessments at baseline, 6 months, and 12 months. At baseline, mothers (mean age = 41.0 years, standard deviation [SD] = 6.1) completed the 10-item Cohen's Perceived Stress Scale (PSS). At each time point, children (51% female, mean age = 9.6 years, SD = 0.9) completed up to two 24-hr dietary recalls. Dietary data were used to calculate each child's Healthy Eating Index 2010 (HEI-2010) score at each time point. Multilevel models examined the effect of time on the patterns of change in children's HEI-2010 scores over 1 year and the cross-level interaction between baseline maternal PSS score and time on the change in children's HEI-2010 scores.

RESULTS

On average, there was no significant linear change in child HEI-2010 across 1 year (b = -0.410, p = .586). Controlling for covariates, the rate of change in HEI-2010 differed depending on mother's baseline PSS (i.e., significant cross-level interaction effect) (b = -0.235, p = .035).

CONCLUSIONS

Our results showed that higher-than-average maternal stress at baseline was associated with greater decline in children's dietary quality over 1 year. Family-based dietary interventions that incorporate maternal stress reduction could have positive effects on children's dietary quality.

The reality of "food porn": Larger brain responses to food-related cues than to erotic images predict cue-induced eating

While some individuals can defy the lure of temptation, many others find appetizing food irresistible. The goal of this study was to investigate the neuropsychological mechanisms that increase individuals' vulnerability to cue-induced eating. Using ERPs, a direct measure of brain activity, we showed that individuals with larger late positive potentials in response to food-related cues than to erotic images are more susceptible to cue-induced eating and, in the presence of a palatable food option, eat more than twice as much as individuals with the opposite brain reactivity profile. By highlighting the presence of individual brain reactivity profiles associated with susceptibility to cue-induced eating, these findings contribute to the understanding of the neurobiological basis of vulnerability to obesity.

Momentary affect, stress coping, and food intake in mother-child dyads

BACKGROUND

Momentary affect and stress in mothers and their children may be an important predictor of food intake in the natural environment. This study hypothesized that there would be parallel actor and partner effects such that mothers' and children's negative affect (NA), positive affect (PA), and ability to cope with stress would be associated with their own and the other dyad member's unhealthy and healthy food intake in a similar pattern.

METHOD

Participants included 202 mother-child dyads (child age range = 8-12 years) who responded to randomly prompted ecological momentary assessment surveys via smartphone up to 7 times per day over 8 days, excluding time at school. At each prompt, mothers and children reported on their current NA, PA, and ability to cope with stress and foods consumed in the past 2 hr.

RESULTS

Mothers' momentary ability to cope with stress predicted their own and their child's pastries/sweets intake and their own fries/chips intake, and children's momentary ability to cope with stress predicted their own pastries/sweets intake. Mothers and children who reported higher NA on average consumed more pastries/sweets, and children with higher NA on average consumed more fast food. Finally, mothers' momentary PA predicted their own fruit/vegetable consumption.

CONCLUSIONS

Findings provided evidence that the affect and ability to cope with stress of children and mothers predicted subsequent food intake. Given both actor and partner effects, the results show that targeting momentary mothers' and children's ability to cope with stress may have the greatest effect on reducing unhealthy food intake. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Mobile Ecological Momentary Diet Assessment Methods for Behavioral Research: Systematic Review

Background

New methods for assessing diet in research are being developed to address the limitations of traditional dietary assessment methods. Mobile device–assisted ecological momentary diet assessment (mEMDA) is a new dietary assessment method that has not yet been optimized and has the potential to minimize recall biases and participant burden while maximizing ecological validity. There have been limited efforts to characterize the use of mEMDA in behavioral research settings.

Objective

The aims of this study were to summarize mEMDA protocols used in research to date, to characterize key aspects of these assessment approaches, and to discuss the advantages and disadvantages of mEMDA compared with the traditional dietary assessment methods as well as implications for future mEMDA research.

Methods

Studies that used mobile devices and described mEMDA protocols to assess dietary intake were included. Data were extracted according to Preferred Reporting of Systematic Reviews and Meta-Analyses and Cochrane guidelines and then synthesized narratively.

Results

The review included 20 studies with unique mEMDA protocols. Of these, 50% (10/20) used participant-initiated reports of intake at eating events (event-contingent mEMDA), and 50% (10/20) used researcher-initiated prompts requesting that participants report recent dietary intake (signal-contingent mEMDA). A majority of the study protocols (60%, 12/20) enabled participants to use mobile phones to report dietary data. Event-contingent mEMDA protocols most commonly assessed diet in real time, used dietary records for data collection (60%, 6/10), and provided estimates of energy and nutrient intake (60%, 6/10). All signal-contingent mEMDA protocols used a near real-time recall approach with unannounced (ie, random) abbreviated diet surveys. Most signal-contingent protocols (70%, 7/10) assessed the frequency with which (targeted) foods or food groups were consumed. Relatively few (30%, 6/20) studies compared mEMDA with the traditional dietary assessment methods.

Conclusions

This review demonstrates that mEMDA has the potential to reduce participant burden and recall bias, thus advancing the field beyond current dietary assessment methods while maximizing ecological validity.

Objectively-Measured Physical Activity and Sedentary Time are Differentially Related to Dietary Fat and Carbohydrate Intake in Children

Background: Research on the clustering of physical activity, sedentary, and dietary intake behaviors in children has relied on retrospective and parent-report measures, which may obscure true associations. The current study combined objectively-measured moderate-to-vigorous intensity physical activity (MVPA) and sedentary time (ST) data from waist-worn accelerometers, with multiple child-report 24-h dietary recalls to assess specific components of dietary intake (i.e., dietary fat, carbohydrates, protein; glycemic load, fruits and vegetables) in children.

Methods: Participants (n = 136, ages 8–12 years) wore an accelerometer for 7 days. On two of those days, children completed 24-h recall phone interviews to assess dietary intake.

Results: After adjusting for child age, sex, ethnicity, annual household income, and body mass index (BMI) percentile; ST was positively associated with percent dietary fat intake, and negatively associated with percent dietary carbohydrate intake and glycemic load (p's < 0.01). MVPA was positively associated with percent dietary carbohydrate intake and daily glycemic load, and negatively associated with percent dietary fat intake (p's < 0.05).

Conclusion: Despite its direct health benefits, physical activity may be associated with consuming greater proportion of total intake from carbohydrates, especially those with a higher glycemic index. Further research is needed to understand the differential implications of these unique behavioral interrelations for diabetes, cardiovascular, and obesity risk.

An Electronic Ecological Momentary Assessment Study to Examine the Consumption of High-Fat/High-Sugar Foods, Fruits/Vegetables, and Affective States Among Women

OBJECTIVE

To examine the associations between high-fat/high-sugar foods (HFHS) and fruit and vegetable (FV) consumption and affective states in women.

METHODS

The researchers used electronic ecological momentary assessment to capture HFHS and FV consumption in the past 2 hours (predictor) and current affective states (outcome) across 1 week among 202 women. Multilevel linear regression was conducted. Weight status was tested as a moderator.

RESULTS

Consumption of FV in the past 2 hours was positively associated with feeling happy (P < .05). Women who consumed more HFHS or fewer FV than others in the study reported higher average sadness (both P < .05). Overweight or obese women who reported more frequent HFHS consumption than others had higher average stress than normal weight women (P < .05).

CONCLUSIONS AND IMPLICATIONS

The association between HFHS consumption and stress might be stronger in overweight or obese than normal weight women. Future studies could further enhance the electronic ecological momentary assessment method to explore other time-varying moderators and mediators of food consumption and affect.

Just-in-Time Feedback in Diet and Physical Activity Interventions: Systematic Review and Practical Design Framework

Background

The integration of body-worn sensors with mobile devices presents a tremendous opportunity to improve just-in-time behavioral interventions by enhancing bidirectional communication between investigators and their participants. This approach can be used to deliver supportive feedback at critical moments to optimize the attainment of health behavior goals.

Objective

The goals of this systematic review were to summarize data on the content characteristics of feedback messaging used in diet and physical activity (PA) interventions and to develop a practical framework for designing just-in-time feedback for behavioral interventions.

Methods

Interventions that included just-in-time feedback on PA, sedentary behavior, or dietary intake were eligible for inclusion. Feedback content and efficacy data were synthesized descriptively.

Results

The review included 31 studies (15/31, 48%, targeting PA or sedentary behavior only; 13/31, 42%, targeting diet and PA; and 3/31, 10%, targeting diet only). All studies used just-in-time feedback, 30 (97%, 30/31) used personalized feedback, and 24 (78%, 24/31) used goal-oriented feedback, but only 5 (16%, 5/31) used actionable feedback. Of the 9 studies that tested the efficacy of providing feedback to promote behavior change, 4 reported significant improvements in health behavior. In 3 of these 4 studies, feedback was continuously available, goal-oriented, or actionable.

Conclusions

Feedback that was continuously available, personalized, and actionable relative to a known behavioral objective was prominent in intervention studies with significant behavior change outcomes. Future research should determine whether all or some of these characteristics are needed to optimize the effect of feedback in just-in-time interventions.

Beyond Cue Reactivity: Non-Drug-Related Motivationally Relevant Stimuli Are Necessary to Understand Reactivity to Drug-Related Cues

Neurobiological models of addiction posit that drug use can alter reward processes in two ways: (1) by increasing the motivational relevance of drugs and drug-related cues and (2) by reducing the motivational relevance of non-drug-related rewards. Here, we discuss the results from a series of neuroimaging studies in which we assessed the extent to which these hypotheses apply to nicotine dependence. In these studies, we recorded smokers’ and nonsmokers’ brain responses to a wide array of motivationally relevant visual stimuli that included pleasant, unpleasant, cigarette-related, and neutral images. Based on these findings, we highlight the flaws of the traditional cue reactivity paradigm and we conclude that responses to non-drug-related motivationally relevant stimuli should be used to appropriately gauge the motivational relevance of cigarette-related cues and to identify smokers attributing higher motivational relevance to drug-related cues than to non-drug-related rewards. Identifying these individuals is clinically relevant as they achieve lower rates of long-term smoking abstinence when attempting to quit. Finally, we show how this approach may be extended beyond nicotine dependence to inform theoretical and clinical research in the study of obesity.

Implications

The cue reactivity paradigm (ie, comparing responses evoked by drug-related cues to those evoked by neutral cues) cannot provide conclusive information about the motivational relevance of drug-related cues. Responses to non-drug-related motivationally relevant stimuli should be used to appropriately gauge the level of motivational relevance that substance-dependent individuals attribute to drug-related cues.

Emotional eating and routine restraint scores are associated with activity in brain regions involved in urge and self-control

Researchers have proposed a variety of behavioral traits that may lead to weight gain and obesity; however, little is known about the neurocognitive mechanisms underlying these weight-related eating behaviors. In this study, we measured activation of reward circuitry during a task requiring response and inhibition to food stimuli. We assessed participants' emotional eating, external eating, and two subscales of dietary restraint-routine restraint and compensatory restraint-using the Weight-Related Eating Questionnaire. For routine restraint, we found positive associations with activation in the insula, dorsolateral prefrontal cortex, anterior cingulate cortex, orbitofrontal cortex and ventromedial prefrontal cortex in response to high-calorie versus low-calorie foods. For emotional eating, we found positive associations with insula and dorsolateral prefrontal cortex activation in response to high-calorie versus low-calorie foods. We also found positive associations between emotional eating and dorsolateral prefrontal cortex activation in response to approach versus inhibition towards high-calorie foods. Thus, our results demonstrate an increase in activation across brain regions related to self-control and urges in response to high-calorie food associated with both emotional eating and routine restraint. Overall, these results support the construct validity of both emotional eating and routine restraint and provide preliminary evidence that these subscales have similar neural correlates.

Dispensing apparatus for use in a cued food delivery task

Neurobiological models of obesity postulate that obese individuals have difficulty regulating food intake partly because they attribute excessive salience to stimuli signaling food availability. Typically, human studies that investigate the relationship between brain responses to food-related stimuli and obesity present food cues without subsequent delivery of food. However, in order to identify the brain correlates of cue reactivity, we must record brain responses to food-related cues signaling food availability. Therefore, we have developed a dispensing apparatus for use in a cued-food delivery task in which event-related potentials (ERPs) to food-related images predicting food delivery and images not predicting food delivery can be recorded. Here, we describe a method where:•The experimental apparatus dispenses an edible item (i.e., a chocolate candy) which may or may not be eaten, or a non-edible control item (e.g., a plastic bead).•Deposit boxes are available to store uneaten candies and the non-edible control items.•The dispensing mechanism is capable of recording the exact timestamp when each delivery event occurs (e.g., release from the dispenser, arrival in the receptacle, storage in the deposit box).

Heterogeneity in brain reactivity to pleasant and food cues: evidence of sign-tracking in humans

Aberrant brain reward responses to food-related cues are an implied characteristic of human obesity; yet, findings are inconsistent. To explain these inconsistencies, we aimed to uncover endophenotypes associated with heterogeneity in attributing incentive salience to food cues in the context of other emotionally salient cues; a phenomenon described as sign- vs goal tracking in preclinical models. Data from 64 lean and 88 obese adults who were 35.5 ± 9.4 years old and predominantly women (79%) were analyzed. Participants viewed food-related, pleasant, neutral and unpleasant images while recording electroencephalograph. Late positive potentials were used to assess incentive salience attributed to the visual stimuli. Eating and affective traits were also assessed. Findings demonstrated that obese individuals, in general, do not demonstrate aberrant brain reward responses to food-related cues. As hypothesized, latent profile analysis of the late positive potential uncovered two distinct groups. 'Sign-trackers' showed greater responses to food-related cues (P < 0.001) but lower responses to pleasant stimuli (P < 0.001) compared with 'goal-trackers'. There were proportionally more obese than lean 'sign-trackers' (P = 0.03). Obese 'sign-trackers' reported significantly higher levels of emotional eating and food craving (P < 0.001). By examining the heterogeneity in brain reactivity to various emotional stimuli, this translational study highlights the need to consider important neurobehavioral endophenotypes of obesity.

Abstract B05: Randomized pilot study of Project BALANCE: a weight gain prevention intervention for breast cancer patients receiving neoadjuvant chemotherapy

Background: Weight gain is a common problem after breast cancer diagnosis and treatment, particularly for women who receive chemotherapy. The weight gain has negative effects on quality of life, increases risk for chronic disease, and may increase risk of breast cancer recurrence. This pilot study tested a behavioral weight gain prevention intervention on weight, waist circumference, and biomarkers related to breast cancer prognosis (sex hormone binding globulin [SHBG], adiponectin, and leptin).

Methods: Thirty-eight breast cancer patients receiving neoadjuvant chemotherapy were randomized to the weight gain prevention intervention or usual care. The intervention focused on exercise (resistance training, aerobic) and eating a low energy dense diet. Participants received 20 sessions during chemotherapy (14 in person, 6 by telephone) and 9 sessions after surgery (3 in person, 6 by telephone). They completed assessments of weight and waist circumference at baseline (T0), mid-chemotherapy (T1), post-chemotherapy (T2), post surgical recovery (T3), after the post-surgical intervention (T4). Serum was collected at T0, T2, and T3 and SHBG, adiponectin, and leptin was assayed by ELISA. Differences between participants in the intervention and usual care groups for weight, waist circumference, and biomarkers were assessed using linear mixed models. All analyses were controlled for baseline values. Missing observations were imputed by worst observation carried forward. We conducted both an intent-to-treat (all participants) and a per protocol analysis where intervention group participants were included if they completed at least 50% of the intervention sessions.

Results: In the intent to treat analysis, the intervention group participants weighed less at T1-T4 (mean difference = 1.12 kg, p = .2225). In the per protocol analysis the mean difference of 1.6 kg was statistically significant (p=.0499). Waist circumference was lower at T1-T4 in the intervention group in both the intent-to-treat analysis (mean difference = 2.8 cm, p=.0354) and the per protocol analysis (mean difference = 3.7 cm, p=.0122). Levels of natural log transformed SHBG were higher for the intervention group at T2-T3; the difference neared significance (intent-to-treat: p=.0914; per protocol analysis: p=.0506), but there was no significant difference between the groups in adiponectin or leptin levels. However, all three biomarkers were significantly correlated with weight, BMI and waist circumference in the expected direction at T0, T2, and T3, with the exception of SHBG at T3, which was significantly correlated with weight only.

Conclusion: A diet and exercise intervention delivered during and after chemotherapy can promote weight loss in breast cancer patients. Given the associations between body composition and prognostic biomarkers, the Project BALANCE intervention could be investigated for its effects on prognosis.

Citation Format: Karen Basen-Engquist, James L. Murray, III, Abenaa Brewster, Susan M. Schembre, Jaejoon Song, Angelica Gutierrez-Barrera, Banu Arun. Randomized pilot study of Project BALANCE: a weight gain prevention intervention for breast cancer patients receiving neoadjuvant chemotherapy. [abstract]. In: Proceedings of the Thirteenth Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2014 Sep 27-Oct 1; New Orleans, LA. Philadelphia (PA): AACR; Can Prev Res 2015;8(10 Suppl): Abstract nr B05.

Effectiveness of lifestyle interventions to reduce binge eating symptoms in African American and Hispanic women

OBJECTIVE

Lifestyle interventions that promote physical activity and healthy dietary habits may reduce binge eating symptoms and be more feasible and sustainable among ethnic minority women, who are less likely to seek clinical treatment for eating disorders. The purpose of this study was to investigate (1) whether participating in a lifestyle intervention is a feasible way to decrease binge eating symptoms (BES) and (2) whether changes in BES differed by intervention (physical activity vs. dietary habits) and binge eating status at baseline (binger eater vs. non-binge eater) in African American and Hispanic women.

METHOD

Health Is Power (HIP) was a longitudinal randomized controlled trial to promote physical activity and improve dietary habits. Women (N = 180) who completed anthropometric measures and questionnaires assessing fruit and vegetable and dietary fat intake, BES and demographics at baseline and post-intervention six months later were included in the current study.

RESULTS

Over one-fourth (27.8%) of participants were categorized as binge-eaters. Repeated measures ANOVA demonstrated significant two- and three-way interactions. Decreases in BES over time were greater in binge eaters than in non-binge eaters (F(1,164) = 33.253, p < .001), and women classified as binge eaters who participated in the physical activity intervention reported greater decreases in BES than non-binge eaters in the dietary habits intervention (F(1,157) = 5.170, p = .024).

DISCUSSION

Findings suggest behavioral interventions to increase physical activity may lead to reductions in BES among ethnic minority women and ultimately reduce the prevalence of binge eating disorder and health disparities in this population.

Association of usual self-reported dietary intake with ecological momentary measures of affective and physical feeling states in children

BACKGROUND

Little is known about the relationship between dietary intake and affective and physical feeling states in children.

PURPOSE

The current study used Ecological Momentary Assessment (EMA) to examine how usual dietary intake is cross-sectionally associated with both average affective and physical feeling state ratings and rating variability in children.

METHODS

Children (N = 110, mean age = 11.0 ± 1.2 years, 52.5% male, 30.1% Hispanic/Latino) completed EMA measures of affective and physical feeling states 3-7 times per day for a full or partial day (weekday evenings and weekend days and evenings) over a 4-day period. Usual intake of pre-selected dietary components was measured prior to the EMA measurement period using the Block Kids Food Screener. Statistical analyses included mixed models and mixed-effects location scale models.

RESULTS

Greater usual fiber intake was cross-sectionally associated with higher average positive affect (PA) ratings, lower variability of NA ratings, and higher variability of physical fatigue ratings. Lower usual glycemic load of diet was cross-sectionally associated with lower variability of NA ratings. Lower usual added sugar intake was cross-sectionally associated with higher average physical energy ratings and lower variability of NA ratings.

CONCLUSIONS

Although temporal precedence was not established by these findings, they indicate that characteristics of children's usual dietary intake are cross-sectionally associated with both the average and variability of affective and physical feeling states. EMA offers a promising avenue through which to explore the associations between affective states and diet and has the potential to provide insight into nuances of this relationship.

The time-varying association between perceived stress and hunger within and between days

OBJECTIVE

Examine the association between perceived stress and hunger continuously over a week in free-living individuals.

METHODS

Forty five young adults (70% women, 30% overweight/obese) ages 18 to 24 years (Mean = 20.7, SD = 1.5), with BMI between 17.4 and 36.3 kg/m(2) (Mean = 23.6, SD = 4.0) provided between 513 and 577 concurrent ratings of perceived stress and hunger for 7 days via hourly, text messaging assessments and real-time eating records. Time-varying effect modeling was used to explore whether the within-day fluctuations in stress are related to perceived hunger assessed on a momentary basis.

RESULTS

A generally positive stress-hunger relationship was confirmed, but we found that the strength of the relationship was not linear. Rather, the magnitude of the association between perceived stress and hunger changed throughout the day such that only during specific time intervals were stress and hunger significantly related. Specifically, the strength of the positive association peaked during late afternoon hours on weekdays (β = 0.31, p < .05) and it peaked during evening hours on weekend days (β = 0.56, p < .05).

CONCLUSION

This is the first empirical study to demonstrate potentially maladaptive, nonlinear stress-hunger associations that peak in the afternoon or evening hours. While we are unable to infer causality from these analyses, our findings provide empirical evidence for a potentially high-risk time of day for stress-induced eating. Replication of these findings in larger, more diverse samples will aid with the design and implementation of real-time intervention studies aimed at reducing stress-eating.

Poor ability to resist tempting calorie rich food is linked to altered balance between neural systems involved in urge and self-control

Background

The loss of self-control or inability to resist tempting/rewarding foods, and the development of less healthful eating habits may be explained by three key neural systems: (1) a hyper-functioning striatum system driven by external rewarding cues; (2) a hypo-functioning decision-making and impulse control system; and (3) an altered insula system involved in the translation of homeostatic and interoceptive signals into self-awareness and what may be subjectively experienced as a feeling.

Methods

The present study examined the activity within two of these neural systems when subjects were exposed to images of high-calorie versus low-calorie foods using functional magnetic resonance imaging (fMRI), and related this activity to dietary intake, assessed by 24-hour recall. Thirty youth (mean BMI = 23.1 kg/m², range = 19.1 - 33.7; age =19.7 years, range = 14 - 22) were scanned using fMRI while performing food-specific go/nogo tasks.

Results

Behaviorally, participants more readily pressed a response button when go trials consisted of high-calorie food cues (HGo task) and less readily pressed the response button when go trials consisted of low-calorie food cues (LGo task). This habitual response to high-calorie food cues was greater for individuals with higher BMI and individuals who reportedly consume more high-calorie foods. Response inhibition to the high-calorie food cues was most difficult for individuals with a higher BMI and individuals who reportedly consume more high-calorie foods. fMRI results confirmed our hypotheses that (1) the "habitual" system (right striatum) was more activated in response to high-calorie food cues during the go trials than low-calorie food go trials, and its activity correlated with participants’ BMI, as well as their consumption of high-calorie foods; (2) the prefrontal system was more active in nogo trials than go trials, and this activity was inversely correlated with BMI and high-calorie food consumption.

Conclusions

Using a cross-sectional design, our findings help increase understanding of the neural basis of one’s loss of ability to self-control when faced with tempting food cues. Though the design does not permit inferences regarding whether the inhibitory control deficits and hyper-responsivity of reward regions are individual vulnerability factors for overeating, or the results of habitual overeating.

Electronic supplementary material

The online version of this article (doi:10.1186/1475-2891-13-92) contains supplementary material, which is available to authorized users.

Development and Validation of the Cognitive Behavioral Physical Activity Questionnaire

PURPOSE

Develop and demonstrate preliminary validation of a brief questionnaire aimed at assessing social cognitive determinants of physical activity (PA) in a college population.

DESIGN

Quantitative and observational.

SETTING

A midsized northeastern university.

SUBJECTS

Convenience sample of 827 male and female college students age 18 to 24 years.

MEASURES

International Physical Activity Questionnaire and a PA stage-of-change algorithm.

ANALYSIS

A sequential process of survey development, including item generation and data reduction analyses by factor analysis, was followed with the goal of creating a parsimonious questionnaire. Structural equation modeling was used for confirmatory factor analysis and construct validation was confirmed against self-reported PA and stage of change. Validation analyses were replicated in a second, independent sample of 1032 college students.

RESULTS

Fifteen items reflecting PA self-regulation, outcome expectations, and personal barriers explained 65% of the questionnaire data and explained 28.6% and 39.5% of the variance in total PA and moderate-to-vigorous-intensity PA, respectively. Scale scores were distinguishable across the stages of change. Findings were similar when the Cognitive Behavioral Physical Activity Questionnaire (CBPAQ) was tested in a similar and independent sample of college students (40%; R (2) moderate-to-vigorous-intensity PA = .40; p < .001).

CONCLUSION

The CBPAQ successfully explains and predicts PA behavior in a college population, warranting its incorporation into future studies aiming at understanding and improving on PA behavior in college students.

Insufficient and excessive amounts of sleep increase the risk of premature death from cardiovascular and other diseases: the Multiethnic Cohort Study

OBJECTIVE

To explore an independent association between self-reported sleep duration and cause-specific mortality.

METHODS

Data were obtained from the Multiethnic Cohort Study conducted in Los Angeles and Hawaii.

RESULTS

Among 61,936 men and 73,749 women with no history of cancer, heart attack or stroke, 19,335 deaths occurred during an average 12.9year follow-up. Shorter (≤5h/day) and longer (≥9h/day) sleepers of both sexes (vs. 7h/day) had an increased risk of all-cause and cardiovascular disease (CVD) mortality, but not of cancer mortality. Multivariable hazard ratios for CVD mortality were 1.13 (95% CI 1.00-1.28) for ≤5h/day and 1.22 (95% CI 1.09-1.35) for ≥9h/day among men; and 1.20 (95% CI 1.05-1.36) for ≤5h/day and 1.29 (95% CI 1.13-1.47) for ≥9h/day among women. This risk pattern was not heterogeneous across specific causes of CVD death among men (Phetero 0.53) or among women (Phetero 0.72). The U-shape association for all-cause and CVD mortality was observed in all five ethnic groups included in the study and by subgroups of age, smoking status, and body mass index.

CONCLUSION

Insufficient or excessive amounts of sleep were associated with increased risk of mortality from CVD and other diseases in a multiethnic population.

Variations in bitter-taste receptor genes, dietary intake, and colorectal adenoma risk

Genetic variants in bitter-taste receptor genes have been hypothesized to negatively impact health outcomes and/or influence dietary intake and, consequently, could increase the risk of colorectal neoplasia. Using a case-control study of 914 colorectal adenoma cases/1188 controls, we explored associations among colorectal adenoma risk, dietary intake, and genetic variation in 3 bitter-taste receptor genes: TAS2R38 (rs713598, rs1726866, rs10246939), TAS2R16 (rs846672), and TAS2R50 (rs1376251). Analysis of covariance was conducted to detect trends in dietary intake across TAS2R genotypes/haplotypes. Odds ratios and 95% confidence intervals were estimated by logistic regression to test gene-adenoma risk associations. No significant associations were observed between the TAS2R38 PAV/PAV diplotype or the TAS2R16 (rs846672) polymorphism with the selected diet variables. We observed weak inverse associations between the TAS2R50 (rs1376251) C allele and dietary fiber and vegetable intake (Ps < 0.015). Odds ratios for adenoma risk were not significantly different from the null. Our findings do not support a link between these TAS2R genotypes/haplotypes and dietary intake that could impact colorectal adenoma risk. However, given the paucity of data, we cannot dismiss the possibility that these genes may influence colorectal adenoma risk in other ways, such as through impaired gastrointestinal function, particularly in subgroups of the population.

Eating breakfast more frequently is cross-sectionally associated with greater physical activity and lower levels of adiposity in overweight Latina and African American girls

BACKGROUND

Eating breakfast is believed to promote a healthy body weight. Yet, few studies have examined the contribution of energy balance-related behavioral factors to this relation in minority youth.

OBJECTIVE

We assessed the associations between breakfast consumption and dietary intake, physical activity (PA), and adiposity before and after accounting for energy intake and PA in minority girls.

DESIGN

Cross-sectional data were obtained on body mass index (BMI), percentage body fat (measured by BodPod), dietary intake (measured with 3-d dietary records), and PA (measured with 7-d accelerometry) from 87 Latina and African American girls 8-17 y of age (75% Latina, 80% overweight). Dietary records were used to categorize girls as more frequent breakfast eaters (MF; 2 or 3 of 3 d; n = 57) or less frequent breakfast eaters (LF; 0 or 1 of 3 d; n = 30). Chi-square tests, ANCOVA, and multiple regression analyses were conducted. Mediation was assessed with a Sobel test.

RESULTS

Compared with the MF group, the LF group spent 30% less time (12.6 min/d) in moderate-to-vigorous-intensity PA (MVPA; P = 0.004) and had a higher percentage body fat (P = 0.029). MVPA accounted for 25% (95% CI: -8.8%, 58.1%; P = 0.139) of the relation between breakfast consumption and percentage body fat. We were unable to show that energy intake or MVPA was a significant mediator of the relation between breakfast consumption and adiposity in this sample.

CONCLUSIONS

Evidence suggests that among predominantly overweight minority girls, MVPA, but not energy intake, was associated with both breakfast consumption and adiposity; however, a lack of power reduced our ability to detect a significant mediation effect. Other unobserved variables likely contribute to this relation.

Process evaluation of Project WebHealth: a nondieting Web-based intervention for obesity prevention in college students

OBJECTIVE

To evaluate the motivational effect of the Project WebHealth study procedures and intervention components on weight-related health behavior changes in male and female college students.

DESIGN

Process evaluation.

SETTING

Eight universities in the United States.

PARTICIPANTS

Project WebHealth participants (n = 653; 29% men).

MAIN OUTCOME MEASURES

Participants rated motivational effects of study procedures and intervention components. Participants were grouped into outcome-based health behavior categories based on achievement of desired targets for fruit and vegetable intake, physical activity, and/or body weight.

ANALYSIS

Differences in motivation from each procedure and component were analyzed by gender- and outcome-based health behavior category.

RESULTS

Women were generally more motivated than men. Compared to those who did not meet any target health behaviors, men with improved health outcomes (68%) were significantly more motivated by the skills to fuel the body lesson, goal setting, and research snippets. Their female counterparts (63%) were significantly more motivated by the lessons on body size and eating enjoyment, and by the suggested weekly activities.

CONCLUSIONS AND IMPLICATIONS

Specific study procedures and components of Project WebHealth motivated study participants to improve their weight-related health behaviors, and they differed by gender. Findings support the need for gender-tailored interventions in this population.

Does the transtheoretical model of behavior change provide a useful basis for interventions to promote fruit and vegetable consumption?

PURPOSE

To determine whether Transtheoretical Model (TTM) constructs differ between individuals making successful versus unsuccessful stage transitions for consumption of five or more servings of fruit and vegetables each day and thus provide a useful basis for designing health promotion interventions.

DESIGN

Longitudinal, observational study. A randomly selected, multiethnic cohort of adults assessed at 6-month intervals over 2 years.

SETTING

General community, Hawaii.

SUBJECTS

There were 700 participants (62.6% female; mean = 47 ± 17.1 years; 31.1% Asian, 22.1% Native Hawaiian/Pacific Islander, 35.0% Caucasian; 25.1% participation rate).

MEASURES

Stage of readiness, experiential and behavioral processes of change, pros, cons, self-efficacy, and self-reported fruit and vegetable consumption.

ANALYSIS

The study used t-tests to determine which TTM variable scores differed consistently between those making "successful" versus "unsuccessful " stage transitions from precontemplation, preparation, and maintenance. Sample sizes for contemplation and action prohibited similar analyses.

RESULTS

Compared to those remaining in precontemplation, individuals successfully progressing from precontemplation showed significantly greater use of behavioral processes (collectively and self-liberation) and consciousness raising (p < .001). However, only self-liberation demonstrated significant differences consistently over time.

CONCLUSION

This longitudinal investigation reveals that TTM behavioral processes, particularly self-liberation, predict successful transition out of precontemplation for adult fruit and vegetable consumption, suggesting that public health messages tailored according to these TTM variables may be effective for this group. However, for adults prepared to adopt or maintain fruit and vegetable consumption, tailoring based on variables from other theories is needed.

Impact of an Online Healthful Eating and Physical Activity Program for College Students

Purpose.

To identify impact of an online nutrition and physical activity program for college students.

Design.

Randomized, controlled trial using online questionnaires and on-site physical and fitness assessments with measurement intervals of 0 (baseline), 3 (postintervention), and 15 months (follow-up).

Setting.

Online intervention delivered to college students; a centralized Web site was used for recruitment, data collection, data management, and intervention delivery.

Subjects.

College students (18–24 years old, n = 1689), from eight universities (Michigan State University, South Dakota State University, Syracuse University, The Pennsylvania State University, Tuskegee University, University of Rhode Island, University of Maine, and University of Wisconsin).

Intervention.

A 10-lesson curriculum focusing on healthful eating and physical activity, stressing nondieting principles such as size acceptance and eating competence (software developer: Rainstorm, Inc, Orono, Maine).

Measures.

Measurements included anthropometrics, cardiorespiratory fitness, fruit/vegetable (FV) intake, eating competence, physical activity, and psychosocial stress.

Analysis.

Repeated measures analysis of variance for outcome variables.

Results.

Most subjects were white, undergraduate females (63%), with 25% either overweight or obese. Treatment group completion rate for the curriculum was 84%. Over 15 months, the treatment group had significantly higher FV intake (+.5 cups/d) and physical activity participation (+270 metabolic equivalent minutes per week) than controls. For both groups, anthropometric values and stress increased, and fitness levels decreased. Gender differences were present for most variables. First-year males and females gained more weight than participants in other school years.

Conclusion.

A 10-week online nutrition and physical activity intervention to encourage competence in making healthful food and eating decisions had a positive, lasting effect on FV intake and maintained baseline levels of physical activity in a population that otherwise experiences significant declines in these healthful behaviors.

Associations between weight-related eating behaviors and adiposity in postmenopausal Japanese American and white women

The purpose of this study was to test the associations between cognitive and psychological eating behavior traits and detailed measures of adiposity and body fat distribution using imaging-based methods in a cross-sectional study. Eating behavior traits (compensatory and routine restraint, external eating, and emotional eating) were assessed using the validated Weight-Related Eating Questionnaire, and measures of adiposity using anthropometry, dual energy X-ray absorptiometry (DXA), and magnetic resonance imaging (MRI). Each adiposity outcome of interest (total fat, ratio of trunk fat to periphery fat, visceral and subcutaneous fats as % of abdominal area, and % liver fat) was regressed on the four eating behaviors while adjusting for age and race/ethnicity. This study included a total of 60 postmenopausal Japanese American (n=30) and white (n=30) women (age: 60-65 years, BMI: 18.8-39.6 kg/m(2)). Weight-related eating behavior traits did not differ by ethnicity. Higher external eating scores were associated with measures of total adiposity, including higher BMI (β=0.36, p=0.02) and DXA total fat mass (β=0.41, p=0.001), and with MRI abdominal subcutaneous fat (β=0.55, p=0.001). Higher routine restraint scores were associated with visceral adiposity (β=0.42, p=0.04). Our findings suggest that different weight-related eating behavior traits might increase not only total adiposity but also abdominal and visceral fat deposition associated with higher metabolic risks. Future research, preferably in a prospective study of men and women and including biomarkers related to psychological stress, will be needed to explore potential underlying biological mechanisms.

Psychometric properties and construct validity of the Weight-Related Eating Questionnaire in a diverse population

This study evaluates the 16-item, four-factor Weight-Related Eating Questionnaire (WREQ), which assesses theory-based aspects of eating behavior, across diverse, nonclinical subgroups. A total of 621 men and women aged 18-81 years (34.3 ± 16.4) with a mean BMI of 25.7 ± 6.1 kg/m(2) (range 15.5-74.1 kg/m(2)) were recruited from general education classes at the University of Hawai'i, Manoa and an online survey panel of Hawai'i residents to complete a web-based survey. Participants were predominantly white (23%), Asian/Asian-mix (42%), or Native Hawaiian/Pacific Islander (18%). The WREQ's factor structure was successfully replicated by confirmatory factor analysis (CFA) for the entire sample and by weight status, gender, age, and race with strong internal consistency. Four-week test-retest reliability (n = 31) for the subscales was excellent with interclass correlations of 0.849-0.932. Tests of population invariance confirmed the generalizability of the WREQ across all subgroups having provided no evidence that the factor structure, factor loadings, or indicator intercepts varied significantly between the groups. Multivariate regression analyses showed that emotional eating was independently associated with BMI (β = 0.272, P < 0.001) as well as moderate- and long-term weight change rates (weight gain) in young adults (β = 0.152, P = 0.042) and adults (β = 0.217, P = 0.001). Compensatory restraint was negatively associated with weight gain in adults (β = -0.133, P = 0.039). Routine restraint and emotional eating were highest among dieters. All associations remained significant after accounting for gender, age, and race. The hypothesized WREQ measurement model demonstrated very good construct validity, confirming the unbiased generalizability of the WREQ measure across sex, age, race, and BMI subgroups, and excellent criterion-related validity with respect to current BMI, weight change, and weight control status.

Race/ethnic differences in desired body mass index and dieting practices among young women attending college in Hawai'i

In accordance with the sociocultural model, race/ethnicity is considered a major influence on factors associated with body image and body dissatisfaction, and eating disorders are often characterized as problems that are primarily limited to young White women from Western cultures. The purpose of this study was to determine whether there are differences that exist by race in desired body weight; the importance placed on those ideals; and dieting strategies among White, Asian American, Native Hawaiian/Pacific Islanders, and other mixed-race young women in Hawai'i. A total of 144 female college students 18-20 years of age were surveyed about body weight as well as eating and exercise habits. Results demonstrated that all the young women wanted to lose weight. However, there were no differences in desired body weight or desired weight change by race after controlling for body mass index suggesting that current weight rather than race/ethnicity is the predominant influence on weight-related concerns. Young White women placed the greatest level of importance on achieving a lower body weight, which corresponded with a greater likelihood to be attempting weight loss (dieting) and greater endorsement of behaviors consistent with weight loss compared to their counterparts. Findings imply that, for young women, race/ethnicity may not have as significant an impact on factors associated with body weight ideals as previously believed. Rather, differences in the value placed on achieving a desired body weight, as it relates to disordered eating, should be further explored among race/ethnic groups.

Identifying clusters of college students at elevated health risk based on eating and exercise behaviors and psychosocial determinants of body weight

Weight gain and an increase in overweight and obesity in college students raise serious health concerns. Weight management interventions for college-age men and women might be more effective if they were tailored to subgroups of students with similar behavioral and psychosocial characteristics associated with body weight status. The purpose of this study was to use cluster analysis to identify homogenous subgroups of college-aged men and women enrolled in a weight gain prevention study (Project WebHealth) using baseline data collected in 2008. Project WebHealth was a 15-month nutrition and physical activity intervention designed to decrease the rate of unwanted weight gain in 1,689 college students at eight geographically diverse universities in the United States. Outcome measures included anthropometrics, fruit and vegetable intake, physical activity, cardiorespiratory fitness, and psychosocial variables associated with weight status in college students. Cluster analysis was performed separately by sex using a two-step clustering procedure using weight-related eating and exercise behaviors and psychosocial variables. Cluster groupings were validated against students' measured weight status and waist circumference as indicators of health risk. The study design was cross-sectional. Results showed that three similar clusters were identified for each sex. Validity of the cluster solution was supported by significant group differences in body mass index and waist circumference with the High Risk cluster at elevated health risk compared to the others. For men, variability in eating competence and cognitive restraint scores contributed most to the difference between clusters, whereas for women, emotional eating and uncontrolled eating scores did. These findings could be used to improve effectiveness of messages and interventions by tailoring them to subgroups of college students with similar behavioral and psychosocial characteristics associated with elevated health risk.

Project TwEATs. A feasibility study testing the use of automated text messaging to monitor appetite ratings in a free-living population

There are no standardized methods for monitoring appetite in free-living populations. Fifteen participants tested a computer-automated text-messaging system designed to track hunger ratings over seven days. Participants were sent text-messages (SMS) hourly and instructed to reply during waking hours with their current hunger rating. Of 168 SMS, 0.6-7.1% were undelivered, varying by mobile service provider. On average 12 SMS responses were received daily with minor variations by observation day or day of the week. Compliance was over 74%, and 93% of the ratings were received within 30-min. Automated text-messaging is a feasible method to monitor appetite ratings in this population.

Non-exercise estimation of VO(2)max using the International Physical Activity Questionnaire

Non-exercise equations developed from self-reported physical activity can estimate maximal oxygen uptake (VO(2)max) as well as submaximal exercise testing. The International Physical Activity Questionnaire (IPAQ) is the most widely used and validated self-report measure of physical activity. This study aimed to develop and test a VO(2)max estimation equation derived from the IPAQ-Short Form (IPAQ-S). College-aged males and females (n = 80) completed the IPAQ-S and performed a maximal exercise test. The estimation equation was created with multivariate regression in a gender-balanced subsample of participants, equally representing five levels of fitness (n = 50) and validated in the remaining participants (n = 30). The resulting equation explained 43% of the variance in measured VO(2)max (SEE = 5.45 ml·kg(-1)·min(-1)). Estimated VO(2)max for 87% of individuals fell within acceptable limits of error observed with submaximal exercise testing (20% error). The IPAQ-S can be used to successfully estimate VO(2)max as well as submaximal exercise tests. Development of other population-specific estimation equations is warranted.