Effects of energy-restricted diets with or without nuts on weight, body composition and glycaemic control in adults: a scoping review.

Energy-restricted (ER) diets promote weight loss and improve body composition and glycaemic control. Nut consumption also improves these parameters. However, less is known about the combined benefit of these two strategies. This scoping review implemented a systematic search of Medline, Embase and Scopus to identify randomised controlled trials evaluating the effect of ER diets with or without nuts on body mass, body composition and glycaemic control in adults. After reviewing titles and abstracts, twenty-nine full-text articles were screened, resulting in seven studies reported in eight papers that met the inclusion criteria. Energy restriction was achieved by prescribing a set energy target or reducing intake by 1000-4200 kJ from daily energy requirements. Interventions ranged from 4 to 52 weeks in duration and contained 42-84 g/d of almonds, peanuts, pistachios or walnuts. While all studies reported that energy restriction resulted in significant weight loss, the addition of nuts to ER diets demonstrated significantly greater weight loss in only approximately half of the included studies (4/7 studies). There was limited evidence to support additional benefits from nuts for body composition measures or glycaemic control. Although improvements in weight loss and glycaemia were not consistent when nuts were included in ER diets, no study revealed an adverse effect of nut consumption on health outcomes. Future studies could explore the effect of consuming different types and amounts of nuts, combined with various levels of energy restriction on weight, body composition and glycaemic control.

Eggs and Cardiovascular Disease Risk: An Update of Recent Evidence.

PURPOSE OF REVIEW: This review summarizes recent evidence published since a previous review in 2018 on the association between egg consumption and risk of cardiovascular disease (CVD) mortality, CVD incidence, and CVD risk factors. RECENT FINDINGS: No recent randomized controlled trials were identified. Evidence from observational studies is mixed, with studies reporting either an increased risk or no association of highest egg consumption with CVD mortality, and a similar spread of increased risk, decreased risk, or no association between egg intake and total CVD incidence. Most studies reported a reduced risk or no association between egg consumption and CVD risk factors. Included studies reported low and high egg intake as between 0 and 1.9 eggs/week and 2 and ≥14 eggs/week, respectively. Ethnicity may influence the risk of CVD with egg consumption, likely due to differences in how eggs are consumed in the diet rather than eggs themselves. Recent findings are inconsistent regarding the possible relationship between egg consumption and CVD mortality and morbidity. Dietary guidance should focus on improving the overall quality of the diet to promote cardiovascular health.

Acute feeding with almonds compared to a carbohydrate-based snack improves appetite-regulating hormones with no effect on self-reported appetite sensations: a randomised controlled trial.

PURPOSE: Early satiety has been identified as one of the mechanisms that may explain the beneficial effects of nuts for reducing obesity. This study compared postprandial changes in appetite-regulating hormones and self-reported appetite ratings after consuming almonds (AL, 15% of energy requirement) or an isocaloric carbohydrate-rich snack bar (SB). METHODS: This is a sub-analysis of baseline assessments of a larger parallel-arm randomised controlled trial in overweight and obese (Body Mass Index 27.5-34.9 kg/m2) adults (25-65 years). After an overnight fast, 140 participants consumed a randomly allocated snack (AL [n = 68] or SB [n = 72]). Appetite-regulating hormones and self-reported appetite sensations, measured using visual analogue scales, were assessed immediately before snack food consumption, and at 30, 60, 90 and 120 min following snack consumption. A sub-set of participants (AL, n = 49; SB, n = 48) then consumed a meal challenge buffet ad libitum to assess subsequent energy intake. An additional appetite rating assessment was administered post buffet at 150 min. RESULTS: Postprandial C-peptide area under the curve (AUC) response was 47% smaller with AL compared to SB (p < 0.001). Glucose-dependent insulinotropic polypeptide, glucagon and pancreatic polypeptide AUC responses were larger with AL compared to SB (18%, p = 0.005; 39% p < 0.001; 45% p < 0.001 respectively). Cholecystokinin, ghrelin, glucagon-like peptide-1, leptin and polypeptide YY AUCs were not different between groups. Self-reported appetite ratings and energy intake following the buffet did not differ between groups. CONCLUSION: More favourable appetite-regulating hormone responses to AL did not translate into better self-reported appetite or reduced short-term energy consumption. Future studies should investigate implications for longer term appetite regulation. ANZCTR REFERENCE NUMBER: ACTRN12618001861246 2018.

The Effect of Commencing Rotating Shift Work on Diet and Body Composition Changes in Graduate Paramedics: A Longitudinal Mixed Methods Study.

Objectives: Diet quality often changes as shift workers adjust to atypical work schedules, however, limited research exists examining the early effects of starting rotating shift work on diet and body composition. This study explored dietary behavior changes occurring in graduate paramedics during the first year of exposure to rotating shift work, and investigated dietary intake, diet quality and anthropometric changes over two years.Methods: Participants from a graduate paramedic cohort in Melbourne, Australia were approached after two years of shift work for study inclusion. Using a mixed method study approach, the qualitative component comprised individual in-depth interviews to explore perceived dietary behavior changes experienced over the first year of shift work. Interview transcripts were thematically analyzed and guided by the COM-B model (capability, opportunity, motivation, and behavior) and theoretical domains framework (TDF). Diet quality and dietary intake were quantitatively assessed by the Australian Eating SurveyTM at baseline, one year, and two years, along with body weight, waist circumference, and body mass index (BMI) to monitor changes.Results: Eighteen participants were included in the study. From the interviews, participants reported: 1. food choices are driven by wanting to fit in with coworker food habits, 2. food choices and mealtimes are unpredictable and 3. paramedics try to make healthy food choices but give in to less healthy options. While daily energy intake and diet quality scores did not differ in the first two years of shift work, daily energy from takeaway foods significantly increased (mean difference (MD): 2.96% EI; 95% CI: 0.44 - 5.48; p = 0.017) and increases in weight (MD: 2.96 kg; 95% CI: 0.89-5.04; p = 0.003), BMI (MD: 1.07 kg/m2; 95% CI: 0.26 - 1.87; p = 0.006) and waist circumference (MD: 5.07 cm; 95% CI: 1.25-8.89; p = 0.006) were also evident at two years.Conclusions: This study contributes new information on dietary changes and the current early trajectory of unintentional weight gain and takeaway reliance occurring within a graduate paramedic cohort over two years of shift work. To reduce the unintended metabolic consequences commonly observed with rotating shift schedules, workplaces could improve access to healthier food options and enable behavioral support/education to address nutrition-related health risks.

The Impact of Meal Timing on Risk of Weight Gain and Development of Obesity: a Review of the Current Evidence and Opportunities for Dietary Intervention.

PURPOSE OF REVIEW: The aim of this short review is to provide an updated commentary on the current literature examining the impact of meal timing on obesity and weight gain in adults. The potential mechanisms, including novel and emerging factors, behind timing of food intake across the 24-h period in the development of obesity, and dietary strategies manipulating meal timing to ameliorate weight gain are also explored. RECENT FINDINGS: Dietary patterns that feature meal timing outside of the regular daytime hours can contribute to circadian disruption as food is metabolised in opposition to internal daily rhythms and can feedback on the timekeeping mechanisms setting these rhythms. Epidemiological evidence examining the impact of late meal timing patterns is beginning to suggest that eating at night increases the risk of weight gain over time. Mechanisms contributing to this include changes to the efficiency of metabolism across the day, and dysregulation of appetite hormone and gut microbiota by mis-timed meals. When meals are eaten, in relation to the time of day, is increasingly considered of importance when implementing dietary change in order to address the growing burden of obesity, although further research is required in order to determine optimal patterns.

Minimal changes in telomere length after a 12-week dietary intervention with almonds in mid-age to older, overweight and obese Australians: results of a randomised clinical trial.

Diet is a modifiable risk factor for chronic disease and a potential modulator of telomere length (TL). The study aim was to investigate associations between diet quality and TL in Australian adults after a 12-week dietary intervention with an almond-enriched diet (AED). Participants (overweight/obese, 50-80 years) were randomised to an AED (n 62) or isoenergetic nut-free diet (NFD, n 62) for 12 weeks. Diet quality was assessed using a Dietary Guideline Index (DGI), applied to weighed food records, that consists of ten components reflecting adequacy, variety and quality of core food components and discretionary choices within the diet. TL was measured by quantitative PCR in samples of lymphocytes, neutrophils, and whole blood. There were no significant associations between DGI scores and TL at baseline. Diet quality improved with AED and decreased with NFD after 12 weeks (change from baseline AED + 9·8 %, NFD - 14·3 %; P < 0·001). TL increased in neutrophils (+9·6 bp, P = 0·009) and decreased in whole blood, to a trivial extent (-12·1 bp, P = 0·001), and was unchanged in lymphocytes. Changes did not differ between intervention groups. There were no significant relationships between changes in diet quality scores and changes in lymphocyte, neutrophil or whole blood TL. The inclusion of almonds in the diet improved diet quality scores but had no impact on TL mid-age to older Australian adults. Future studies should investigate the impact of more substantial dietary changes over longer periods of time.

A scoping review of chronotype and temporal patterns of eating of adults: tools used, findings, and future directions.

Circadian rhythms, metabolic processes and dietary intake are inextricably linked. Timing of food intake is a modifiable temporal cue for the circadian system and may be influenced by numerous factors, including individual chronotype - an indicator of an individual's circadian rhythm in relation to the light-dark cycle. This scoping review examines temporal patterns of eating across chronotypes and assesses tools that have been used to collect data on temporal patterns of eating and chronotype. A systematic search identified thirty-six studies in which aspects of temporal patterns of eating, including meal timings; meal skipping; energy distribution across the day; meal frequency; time interval between meals, or meals and wake/sleep times; midpoint of food/energy intake; meal regularity; and duration of eating window, were presented in relation to chronotype. Findings indicate that, compared with morning chronotypes, evening chronotypes tend to skip meals more frequently, have later mealtimes, and distribute greater energy intake towards later times of the day. More studies should explore the difference in meal regularity and duration of eating window amongst chronotypes. Currently, tools used in collecting data on chronotype and temporal patterns of eating are varied, limiting the direct comparison of findings between studies. Development of a standardised assessment tool will allow future studies to confidently compare findings to inform the development and assessment of guidelines that provide recommendations on temporal patterns of eating for optimal health.

Diet and cognitive function in cancer survivors with cancer-related cognitive impairment: A qualitative study.

OBJECTIVE: To identify cancer survivors' perceptions of the role diet plays in their cognitive function, and how their cancer-related cognitive changes influence their diet. METHODS: Cancer survivors diagnosed with cancer in the past 5 years, not on active treatment, and with self-reported cognitive changes since diagnosis were recruited from the general population. Semi-structured interviews were conducted with 15 Australian breast (n = 13) and colorectal (n = 2) survivors (mean time since diagnosed: 27.0 months ± SD=16.8). Questions related to how their diet and cognitive changes influenced each other. Interviews were recorded, and transcripts were analysed using thematic analysis. RESULTS: Four themes related to how diet impacted cognition: (a) directly (e.g. healthy diet improves cognition), (b) indirectly (e.g. diet affects tiredness which affects cognition); (c) no impact; and (d) potentially (e.g. poorer diet quality would worsen cognition). Three themes emerged for how cognitive changes were thought to impact survivors' diets: (a) planning meals is harder; (b) cooking is more difficult and complex; and, (c) choosing healthy is more challenging. CONCLUSIONS: Many cancer survivors perceived a bidirectional influence between diet and cognition that has cognitive and behavioural consequences. Diet could be investigated as a modifiable lifestyle behaviour to improve cancer-related cognitive impairment and fatigue. Survivors may benefit from dietary guidance with meal planning and preparing.

The impact of caffeine consumption during 50 hr of extended wakefulness on glucose metabolism, self-reported hunger and mood state.

Caffeine is known for its capacity to mitigate performance decrements. The metabolic side-effects are less well understood. This study examined the impact of cumulative caffeine doses on glucose metabolism, self-reported hunger and mood state during 50 hr of wakefulness. In a double-blind laboratory study, participants were assigned to caffeine (n = 9, 6M, age 21.3 ± 2.1 years; body mass index 21.9 ± 1.6 kg/m2 ) or placebo conditions (n = 8, 4M, age 23.0 ± 2.8 years; body mass index 21.8 ± 1.6 kg/m2 ). Following a baseline sleep (22:00 hours-08:00 hours), participants commenced 50 hr of sleep deprivation. Meal timing and composition were controlled throughout the study. Caffeine (200 mg) or placebo gum was chewed for 5 min at 01:00 hours, 03:00 hours, 05:00 hours and 07:00 hours during each night of sleep deprivation. Continual glucose monitors captured interstitial glucose 2 hr post-breakfast, at 5-min intervals. Hunger and mood state were assessed at 10:00 hours, 16:30 hours, 22:30 hours and 04:30 hours. Caffeine did not affect glucose area under the curve (p = 0.680); however, glucose response to breakfast significantly increased after 2 nights of extended wakefulness compared with baseline (p = 0.001). There was a significant main effect of day, with increased tiredness (p < 0.001), mental exhaustion (p < 0.001), irritability (p = 0.002) and stress (p < 0.001) on the second day of extended wake compared with day 1. Caffeine attenuated the rise in tiredness (p < 0.001), mental exhaustion (p = 0.044) and irritability (p = 0.018) on day 1 but not day 2. Self-reported hunger was not affected by sleep deprivation or caffeine. These data confirm the effectiveness of caffeine in improving performance under conditions of sleep deprivation by reducing feelings of tiredness, mental exhaustion and irritability without exacerbating glucose metabolism and feelings of hunger.

Total dietary sugar consumption does not influence sleep or behaviour in Australian children.

This study aimed to compare sugar intake in Australian children with current guidelines and determine if total sugar consumption as a percentage of energy (sugar %E) exacerbates the relationship between sleep and behaviour. A sample of 287 children aged 8-12 years (boys 48.8%, age: 10.7 ± 1.3 years), and their parents/guardians completed a battery of questionnaires. Children completed a food frequency questionnaire, and parents completed demographic, sleep, and behaviour questionnaires. Average sugar intake was 134.9 ± 71.7 g per day (sugar %E 26.0 ± 7.0%), and only 55 (19%) participants did not exceed the recommended sugar intake limit. Correlations and logistical regressions indicated that sugar %E was not associated with sleep or behavioural domains (r range = -0.07-0.08; p range = .173-.979) nor contributed to the prediction of sleep behaviour problems (p range = .16-.80). Whilst a high proportion of children consumed above the recommended amount of daily total sugar, total sugar consumption was not related to behavioural or sleep problems, nor affected the relationship between these variables.

Cerebrovascular and cognitive benefits of high-oleic peanut consumption in healthy overweight middle-aged adults.

OBJECTIVE: Peanuts contain bioactive nutrients beneficial for vascular function. This study investigated whether consumption of unsalted peanuts (with skins) would enhance cerebrovascular perfusion and cognitive performance. METHOD: In a randomized crossover trial, 61 volunteers (29 males/32 females, 65 ± 7 years, BMI 31 ± 4 kg/m2) consumed their habitual diet ± high-oleic peanuts (56-84 g/day), each for 12 weeks. Nutrient intakes, vascular and cognitive function were assessed at baseline and at the end of each 12-week phase. Differences between the ends of each phase were compared by general linear repeated measures ANOVA controlling for baseline. Pearson's correlation analyses determined relationships between differences in cerebrovascular reactivity (CVR) and cognitive function. RESULTS: Intakes of bioactive nutrients increased during the peanut phase. CVR was 5% greater in the left middle cerebral artery (MCA) and 7% greater in the right MCA. Small artery elasticity was 10% greater after peanut consumption; large artery elasticity and blood pressure did not differ between phases. Measures of short-term memory, verbal fluency, and processing speed were also higher following the peanut phase; other cognitive measures did not change. Differences in CVR in the left MCA correlated with differences in delayed memory and recognition. DISCUSSION: Regular peanut consumption improved cerebrovascular and cognitive function; increased intakes of bioactive nutrients may have mediated these improvements. This clinical trial was registered with the Australian Clinical Trials Registry (ACTRN 12612000192886).

Use-of-time and health-related quality of life in 10- to 13-year-old children: not all screen time or physical activity minutes are the same.

PURPOSE: To investigate associations between aspects of time use and health-related quality of life (HRQoL) in youth. METHODS: 239 obese and healthy-weight 10- to 13-year-old Australian children completed the Pediatric Quality of Life Inventory (PedsQL™) quantifying their health-related quality of life. Time use was evaluated over four days using the Multimedia Activity Recall for Children and Adolescents (MARCA), a validated 24 h recall tool. The average number of minutes/day spent in physical activity (divided into sport, active transport and play), screen time (divided into television, videogames and computer use), and sleep were calculated. Percent fat was measured using dual-energy X-ray absorptiometry, Tanner stage by self-report, and household income by parental report. Sex-stratified analysis was conducted using Partial Least Squares regression, with percent fat, Tanner stage, household income, and use-of-time as the independent variables, and PedsQL™ total, physical and psychosocial subscale scores as the dependent variables. RESULTS: For boys, the most important predictors of HRQoL were percent fat (negative), videogames (negative), sport (positive), and Tanner stage (negative). For girls, the significant predictors were percent fat (negative), television (negative), sport (positive), active transport (negative), and household income (positive). CONCLUSION: While body fat was the most significant correlate of HRQoL, sport was independently associated with better HRQoL, and television and videogames with poorer HRQoL. Thus, parents and clinicians should be mindful that not all physical activity and screen-based behaviours have equivocal relationships with children's HRQoL. Prospective research is needed to confirm causation and to inform current activity guidelines.

There is No Association Between the Omega-3 Index and Depressive Symptoms in Patients With Heart Disease Who Are Low Fish Consumers.

BACKGROUND: Long chain Omega-3 polyunsaturated fatty acids (LCn3PUFAs) may improve cardiovascular health and depression. This study investigated the relationships between erythrocyte membrane LCn3PUFA status, depression and angina symptoms in patients with heart disease. METHODS: We recruited 91 patients (65 males and 26 females, mean age 59.2±10.3 years) with heart disease and depressive symptoms (Center for Epidemiological Studies Depression Scale, CES-D ≥ 16) and low fish/fish oil intakes. The Omega-3 Index (EPA+DHA) of erythrocyte membranes (as a percentage of total fatty acids) was assessed by gas chromatography. Depression status was measured by both self-report and clinician-report scales; CES-D and the Hamilton depression scale (HAM-D). Angina symptoms were measured using the Seattle Angina Questionnaire and the Canadian Cardiovascular Society Classification for Angina Pectoris. RESULTS: The mean Omega-3 Index was 4.8±1.0% (±SD). Depression scores measured by CES-D and HAM-D were 29.2±8.8 (moderate to severe) and 11.0±5.7 (mild) (arbitrary units) respectively reflecting a different perception of depressive symptoms between patients and clinicians. Angina status was inversely associated with depression scores (r>-0.26, P<0.03). There were no significant relationships between individual LCn3PUFA or the Omega-3 Index and either the depression scores or the angina symptoms. CONCLUSION: Worse angina status was associated with worse depression, but the Omega-3 Index was not associated with symptoms of depression or angina in patients with heart disease.

No Effect of a Whey Growth Factor Extract during Resistance Training on Strength, Body Composition, or Hypertrophic Gene Expression in Resistance-Trained Young Men.

Growth factors can be isolated from bovine milk to form a whey growth factor extract (WGFE). This study examined whether WGFE promoted activation of the AKT/mTOR pathway enabling increased lean tissue mass and strength in resistance trained men. Forty six men with >6 months of resistance training (RT) experience performed 12 weeks of RT. Participants consumed 20 g/day of whey protein and were randomised to receive either 1.6 g WGFE/day (WGFE; n = 22) or 1.6 g cellulose/day (control, CONT; n = 24). The primary outcome was leg press one-repetition maximum (LP1-RM) which was assessed at baseline, 6 and 12 weeks. At baseline and 12 weeks body composition was assessed by dual energy x-ray absorptiometry, and muscle protein synthesis and gene expression were assessed (vastus lateralis biopsy) in a sub-sample (WGFE n = 10, CONT n = 10) pre- and 3 hr post-training. RT increased LP1-RM (+34.9%) and lean tissue mass (+2.3%; p < 0.05) with no difference between treatments (p > 0.48, treatment x time). Post-exercise P70s6k phosphorylation increased acutely, FOXO3a phosphorylation was unaltered. There were no differences in kinase signalling or gene expression between treatments. Compared with CONT, WGFE did not result in greater increases in lean tissue mass or strength in experienced resistance trained men.

Nut consumption for vascular health and cognitive function.

Nuts are rich in many nutrients that can benefit multiple cardiometabolic functions, including arterial compliance, blood pressure, inflammation, glucoregulation and endothelial vasodilatation. Impaired vasodilatation may contribute to impaired cognitive performance due to poor cerebral perfusion. The present narrative review examines associations between nut consumption, vascular health and cognitive function. It includes a systematic search which identified seventy-one epidemiological or intervention studies in which effects of chronic nut consumption on blood pressure, glucoregulation, endothelial vasodilator function, arterial compliance, inflammatory biomarkers and cognitive performance were evaluated. Weighted mean changes were estimated where data were available; they indicate that nut consumption reduces blood pressure and improves glucoregulation, endothelial vasodilator function and inflammation, whilst a limited number of studies suggest that nut consumption may also improve cognitive performance. Further clinical trials are warranted to explore relationships between nut consumption, endothelial function and cognitive function.

Lower energy intake following consumption of Hi-oleic and regular peanuts compared with iso-energetic consumption of potato crisps.

Snack foods can contribute a high proportion of energy intake to the diet. Peanuts are a snack food rich in unsaturated fatty acids, protein and fibre which have demonstrated satiety effects and may reduce total energy intake, despite their high energy density. This study examined the effects of consuming Hi-oleic (oleic acid ~75% of total fatty acids) peanuts and regular peanuts (oleic acid ~50% and higher in polyunsaturated fatty acids) compared with a high carbohydrate snack (potato crisps) on satiety and subsequent energy intake. Using a triple crossover study design, 24 participants (61 ± 1 years) consumed iso-energetic amounts (56-84 g) of Hi-oleic or regular peanuts or (60-90 g) potato crisps after an overnight fast. Hunger and satiety were assessed at baseline, 30, 60, 120 and 180 minutes following snack consumption using visual analogue scales, after which a cold buffet meal was freely consumed and energy intake measured. The same snack was consumed on 3 subsequent days with energy intake assessed from dietary records. This protocol was repeated weekly with each snack food. Total energy intake was lower following consumption of Hi-oleic and regular peanuts compared with crisps, both acutely during the buffet meal (-21%; p<.001 and -17%; p< .01) and over the 4 days (-11%; p< .001 and -9%; p< .01). Despite these reductions in energy intake, no differences in perceived satiety were observed. The findings suggest peanuts may be a preferred snack food to include in the diet for maintaining a healthy weight.

Study protocol for a 15-week randomised controlled trial assessing the independent effects of high-cholesterol and high-saturated fat diets on LDL cholesterol.

INTRODUCTION: Previous research has associated high dietary cholesterol intake with raised low-density lipoprotein cholesterol (LDL-C) and thus increased risk for cardiovascular disease (CVD). Emerging research suggests that it is saturated fat, not dietary cholesterol, associated with increased CVD risk. Despite being high in cholesterol, eggs, low in saturated fat, are not adversely associated with blood lipids or CVD risk. This paper describes a randomised controlled counter-balanced, cross-over trial assessing the effects of a high-cholesterol/low-saturated fat (egg) diet and a low-cholesterol/high-saturated fat diet (egg free) on blood lipids and lipoproteins, while accounting for physical activity levels which can also influence these parameters. The primary aim is to demonstrate that high cholesterol intake (from eggs) within a healthy, low-saturated fat diet does not adversely affect blood lipid levels and lipoprotein profiles. Instead, we propose that adverse effects on these parameters are mediated by saturated fat intake. The secondary aim is to explore relationships between changes in blood lutein and zeaxanthin concentrations and alterations in physical activity, examining whether changes in physical activity mediate effects on blood lipids and lipoproteins. METHODS AND ANALYSIS: Fifty-two adults aged 18-60 years with LDL-C less than 3.5 mmol/L will be randomly allocated to three isocaloric diets for 5 weeks each: a high-cholesterol (600 mg)/low-saturated fat (6%) (egg) diet, a low-cholesterol (300 mg)/high-saturated fat (12%) (egg free) diet and a control diet that is high in both cholesterol (600 mg) and saturated fat (12%). Lipid and lipoprotein levels, lipoprotein size and concentrations, blood pressure, blood glucose, physical activity levels, and plasma lutein and zeaxanthin concentrations will be measured. Treatment effects will be analysed using linear mixed effects models. ETHICS AND DISSEMINATION: Ethics approval was obtained from the University of South Australia Human Research Ethics Committee no. 204 327. Results will be disseminated through peer-reviewed journals and national and international presentations. TRIAL REGISTRATION NUMBER: NCT05267522.

Characterising concurrent pain experience and dietary patterns in people with chronic musculoskeletal pain: a feasibility study protocol.

INTRODUCTION: Nutrition-related factors linked to pain chronicity and disability include weight status and dietary behaviours. Dietary patterns associated with concurrent pain episodes, however, remain poorly characterised. This paper outlines the protocol for a feasibility study that aims to characterise pain-related dietary and lifestyle behaviours in people experiencing chronic musculoskeletal pain. METHODS: The study will recruit participants who experience musculoskeletal pain on 5 or more days of the week for at least 3 months. Participants will attend two in-person clinic visits where physical measurements and a series of pain and lifestyle questionnaires will be completed. Visits will be conducted pre and post a 2-week self-monitoring period where participants will self-report concurrent diet, sleep, mood, and pain on four days and will wear a wrist-worn activity monitor (GENEActiv). Key feasibility metrics will evaluate participant recruitment, enrolment and retention rates, and compliance with the study data collection protocol. DISCUSSION: There remains a lack of evidence behind dietary advice as an adjunct pain management tool. Upon completion of the protocol, feasibility outcomes will identify challenges to guide the design and delivery of a dietary intervention for chronic musculoskeletal pain.

Construct validity and test-retest reliability of a chrononutrition questionnaire for shift work and non-shift work populations.

The irregular eating patterns of both shift workers and evening chronotypes adversely affect cardiometabolic health. A tool that conveniently captures temporal patterns of eating alongside an indicator of circadian rhythm such as chronotype will enable researchers to explore relationships with diverse health outcome measures. We aimed to investigate the test-retest reliability and convergent validity of a Chrononutrition Questionnaire (CNQ) that captures temporal patterns of eating and chronotype in the general population (non-shift workers, university students, retirees, unemployed individuals) and shift work population. Participants attended two face-to-face/virtual sessions and completed the CNQ and food/sleep/work diaries. Outcomes included subjective chronotype, wake/sleep/mid-sleep time, sleep duration, meal/snack regularity, meal/snack/total frequency, times of first/last/largest eating occasions (EO), main meal (MM) 1/2/3, and duration of eating window (DEW). 116 participants enrolled (44.5 ± 16.5 years, BMI: 27.3 ± 5.8 kg/m2, 73% female, 52% general population); 105 completed the study. Reliability was acceptable for chronotype, sleep, and all temporal eating patterns except on night shifts. Convergent validity was good for chronotype and sleep except for certain shift/shift-free days. Generally, meal/snack regularity and frequency, and times of first/last EO showed good validity for the general population but not shift workers. Validity was good for DEW (except work-free days and afternoon shifts) and times of MM 1/2/3 (except afternoon and night shifts), while time of largest EO had poor validity. The CNQ has good test-retest reliability and acceptable convergent validity for the general and shift work population, although it will benefit from further validation, especially regarding regularity, frequency, and times of first and last eating occasions across more days amongst a larger sample size of shift workers. Use of the CNQ by researchers will expand our current understanding of chrononutrition as relationships between timing of food intake and the multitude of health outcomes are examined.