Energy balance measurement: when something is not better than nothing

Menopause and Body Composition: A Complex Field

Given that menopause affects about half of the world's midlife population, it is crucial to understand its impact beyond traditional menopausal symptomology. For instance, many women, while transitioning through menopause, experience profound changes in body composition. These changes may contribute to postmenopausal reductions in metabolic health. This narrative review explores the influence of menopause on skeletal muscle and adipose tissue, highlighting the decline in muscle mass and strength and the gain and redistribution of adipose tissue, particularly the increase in visceral adiposity. Although menopausal changes in body composition are seemingly extensively studied, the longitudinal studies are not that common, and the precise mechanisms driving body composition changes remain unclear, with uncertainties surrounding the roles of hormonal shifts compared with regular aging, energy balance, and lifestyle factors. Notably, it remains debated whether menopause or estrogen meaningfully influences resting energy expenditure. The review also considers the potential mitigating effects of menopausal hormone therapy and regular exercise. Understanding these changes is essential for developing effective strategies to support women's health during and after menopause.

Isotope Dilution for Measuring Total Energy Expenditure, Water Turnover, and Total Body Water in Athletes: A Systematic Review

Isotope-based tracer methods allow the determination of total energy expenditure (TEE), water turnover (rH2O), and total body water (TBW) in free-living conditions. These methods have exciting applications in athletes. However, the limited number of available measurements constrains their applicability. The aim was to describe the application of isotope dilution techniques for measuring TEE, rH2O, and TBW in athletic populations. A comprehensive search (https://doi.org/10.17605/OSF.IO/7932T) was performed in three databases: PubMed, EBSCO (CINAHL, MEDLINE, and SPORTDiscus), and Cochrane Library. A total of 1,540 records were identified (564 excluded) and 174 through other sources. After excluding 53 duplicates, 1,097 articles were screened. A total of 121 studies were included, totaling 3,244 measurements from different types of sports, age range, and tier level, with 1,020 from female athletes and 139 measurements where sex was not reported. For TEE, 75 studies were included with values ranging from 1,939 to 10,070 kcal/day. For rH2O, 15 studies were included with values ranging from 2.7 to 13.4 L/day. For TBW, 77 studies were included with values ranging from 29.8 to 76.8 kg. Variability was observed across the studies among the variables of interest. Overall, males showed higher TEE, rH2O, and TBW values than females, with endurance sports showing the greatest variability in energy and water flux, and TBW values varying most in team and mixed sports. Future research should increase representation of females, athletes with disabilities, and Tier 5 "world-class" athletes to establish normative values across sports, age groups, and sex while applying standardized isotope dilution methodologies.

Dietary Sugar Intake and Incident Type 2 Diabetes Risk: A Systematic Review and Dose-Response Meta-Analysis of Prospective Cohort Studies

The dose-response relationship between dietary sugar and type 2 diabetes (T2D) risk is uncertain. MEDLINE, Embase, CINAHL, Web of Science and Cochrane databases were searched through July 9, 2024 for prospective cohort studies reporting relative measures of incident T2D risk by categories of dietary sugar (total, free, added, fructose, sucrose) or 2 beverage sources (non-diet sugar-sweetened beverages [SSBs], fruit juice) in healthy adults. Linear and restricted cubic spline dose-response models were fitted for each exposure, and study-specific slopes and confidence intervals (CIs) were calculated. Heterogeneity was evaluated using Q-statistics. Risk of bias was evaluated using the Risk of Bias in Non-randomized Studies of Exposures (ROBINS-E) tool. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was applied to assess the certainty of evidence. Of 10,384 studies, 29 cohorts were included: SSB: 18 (n = 541,288); fruit juice: 14 (n = 490,413); sucrose: 7 (n = 223,238); total sugar: 4 (n = 109,858); fructose: 5 (n = 158,136); and added sugar: 2 (n = 31,004). Studies were conducted in Europe (13), United States (11), Asia (6), Australia (4), and Latin America (3). Each additional serving of SSB and fruit juice was associated with a higher risk of T2D (risk ratio [RR]: 1.25; 95% CI: 1.17, 1.35 and RR: 1.05; 95% CI: >1.00, 1.11, respectively; moderate certainty). In contrast, 20 g/d intakes of total sugar and sucrose were inversely associated with T2D (RR: 0.96; 95% CI: 0.94, 0.98; low certainty; and RR: 0.95; 95% CI: 0.91, <1.00; moderate certainty, respectively). No associations were found for added sugar (RR: 0.99; 95% CI: 0.96, 1.01; low certainty) or fructose (RR: 0.98; 95% CI: 0.83, 1.15; very low certainty). These findings suggest that dietary sugar consumed as a beverage (SSB and fruit juice) is associated with incident T2D risk. The results do not support the common assumption that dietary sugar (i.e., total sugar and sucrose), irrespective of type and amount, is consistently associated with increased T2D risk. This study was registered in PROSPERO as CRD42023401800.

Metabolomic profiling of a cholesterol lowering plant-based diet from two randomized controlled feeding trials

BACKGROUND

Objective biomarkers of diet, such as metabolomics, may improve dietary assessment and provide additional insight into how diet influences disease risk. The portfolio diet, a cholesterol-lowering plant-based diet, is recommended for lowering low-density lipoprotein cholesterol (LDL-C). This diet is low in saturated fat and includes nuts, plant protein (legumes), viscous fiber, and phytosterols.

OBJECTIVE

We examined metabolomic profiles in response to the portfolio diet in two randomized controlled trials (RCTs), where all foods were provided to the participants, compared to a control vegetarian diet and the same control diet with a statin.

METHODS

The first RCT included 34 adults (age 58.4 ± 8.6 y) and the second RCT included 25 adults (age 61.0 ± 9.6 y), all with high LDL-C (>4.1 mmol/L). Plasma samples were obtained at baseline, week 2, and week 4 in both RCTs for metabolomics analysis using liquid chromatography-tandem mass spectrometry. Linear mixed models were used to examine effects of the interventions on the metabolites in each RCT, applying a Bonferroni correction.

RESULTS

Of 496 known metabolites, 145 and 63 metabolites significantly changed within the portfolio diet interventions in the first and second RCT, respectively. The majority were glycerophosphocholines (32%), triacylglycerols (20%), glycerophosphoethanolamines (14%), sphingomyelins (8%), and amino acids and peptides (8%) in the first RCT, and glycerophosphocholines (48%), glycerophosphoethanolamines (17%), and amino acids and peptides (8%) in the second RCT. Fifty-two metabolites were consistently changed in the same direction with the portfolio diet intervention across both RCTs, after Bonferroni correction.

CONCLUSIONS

Many of these metabolites likely reflect the plant-based nature, low saturated fat content, and cholesterol-lowering effects of the diet, such as increased N2-acetylornithine, L-pipecolic acid, lenticin, and decreased C18:0 lipids and cholesteryl esters. Further research is needed to validate these metabolites as biomarkers of a plant-based dietary pattern.

Improved food habits and anthropometry among primary school children following a novel healthy eating programme

OBJECTIVE

Assess longer-term changes in food habits and anthropometry among Grades 1-2 primary school students from four public schools in Colombo, Sri Lanka, following a 3-week programme including a classroom-based motivational storybook discussion and self-monitoring food diary (FD).

METHODS

This follow-up study assessed changes from baseline (pre-intervention) BMI z-scores and food habits (increased healthy food-item consumption/decreased unhealthy food-item consumption reflected by an increase in FD score) and parental perceptions (anonymous questionnaires) among 863 students (aged 6-8 years), between 9 and 12 months after completing the programme (November 2019-February 2020).

RESULTS

Food habits showed sustained improvement from baseline mean FD score (baseline vs. follow-up: 51 ± 23% vs. 67 ± 22%, p < 0.001), with children from all BMI subgroups (underweight [UW], normal weight [NW], overweight [OW] and obesity [OB]) showing a significant increase in FD scores (ranging from 14.1% to 17.2%, p < 0.001). BMI z-scores increased in children living with UW (-2.85 to -2.21, p < 0.00) and NW (-0.70 to -0.57, p < 0.001), but did not change in children with OW (+1.5 to +1.49, p = 0.83) and OB (+2.85 to +2.21, p = 0.19). Most parents (n = 497, 97.8%) reported satisfaction with programme outcomes.

CONCLUSION

This programme led to sustained improvement in food habits among young primary school children from all BMI categories, increase in BMI towards the median among children living with UW and NW, and stabilization of BMI in children with OW and OB, suggesting it as a useful tool for improving nutritional status of young children in low- and middle-income countries (LMIC) facing the double burden of under- and overnutrition.

Special Diets and Nutrient Intakes in Morbidly Obese US Adults in Comparison to the 2020-2025 Dietary Guidelines for Americans

BACKGROUND

Morbid Obesity (MO), defined by a Body Mass Index (BMI) > 40 kg/m2, is the most severe form of obesity. The risk of suffering from any chronic medical condition is almost twice as high in MO as compared to overweight. Despite obesity being one of the most serious contemporary public health concerns, there is a paucity of nutrient intake data in adults with MO. Nutritional assessments in morbidly obese adults are often based on individuals seeking weight loss surgery rather than focusing on the general community.

METHODS

Using National Health and Nutrition Examination Surveys data (NHANES, 2007-2016), we estimated nutrient intakes in the general US population with MO, thereby focusing on a comparative assessment to the Dietary Guidelines for Americans (DGA, 2020-2025). Nutrient intakes were assessed in morbidly obese US adults with a BMI > 40 kg/m2, regardless of their intention to seek weight loss treatment and regardless of reporting special diets. Sex- and age-specific nutrient intake assessments were performed, with the aim to identify population subgroups that may warrant particular attention from a public health perspective.

RESULTS

The study sample comprised 1,708 participants with MO. This may be extrapolated to represent 14,047,276 US Americans. MO was more prevalent in females as compared to males (65.60% vs 34.40%) and the sample's average age was 46.25 years, with a tendency towards a lower mean age in higher BMI groups. The alignment with the DGA was poor across both sexes, and particularly with regard to the nutrients of public health concern (fiber, calcium), saturated fatty acid intake and the intakes of several fat-soluble vitamins. Fiber intake was found to be particularly low in females with MO. Total energy intake was not associated with BMI in participants with MO. Morbidly obese individuals frequently reported special diets, with up to 28% of the examined population disclosing at least one special diet.

CONCLUSIONS

Using a descriptive epidemiological approach, we identified numerous sociodemographic and nutritional factors associated with MO. The poor alignment with US national dietary guidelines warrants special considerations and dedicated public health nutrition efforts to combat the increasing obesity-related burden.

The Effect of the Menstrual Cycle on Energy Intake: A Systematic Review and Meta-analysis

CONTEXT

Energy intake may differ across the menstrual cycle, with some studies identifying greater energy intake in the luteal phase (LP) compared with the follicular phase (FP) and others finding no clear differences. To date, no study has systematically synthesized the available data to draw more definite conclusions while considering any methodological inconsistencies between studies.

OBJECTIVE

The aim was to conduct a systematic review/meta-analysis in an effort to determine if there are differences in energy intake between the FP and LP.

DATA SOURCES

A systematic search strategy was developed and the search was conducted in 5 databases for studies that investigated any changes in energy intake across menstrual phases.

DATA EXTRACTION

Using Covidence, studies were identified and included if they contained individuals between the ages of 18 and 45 years, maintained an average body mass index (BMI) of 18.5-25 kg/m2, had no history of disordered eating, and included energy intake and menstrual cycle measurements in the FP and LP.

DATA ANALYSIS

Effect sizes were calculated for each study and a random-effects model was used to pool the results of each study.

RESULTS

Fifteen datasets were included consisting of 330 female participants with a mean age of 26 ± 4 years and mean BMI of 22.4 ± 2.3 kg/m2. Overall, there was a statistically significant difference (standardized mean difference = 0.69; P = .039) with increased energy intake in the LP compared with the FP (crude 168 kcal⋅d-1 average difference between phases).

CONCLUSION

Energy intake was found to be greater in the LP compared with the FP, providing insight into the effect of the menstrual cycle on energy intake. However, there were repeated methodological inconsistencies and future work should strive to utilize best practices for both energy intake measurement and menstrual phase specification.

Associations of Device-Measured Physical Activity and Sedentary Time With Neural Responses to Visual Food Cues in Adults: A Functional Magnetic Resonance Imaging Study

Self-reported physical activity is associated with lower brain food cue responsiveness in reward-related regions, but relationships utilizing objective physical activity measurement tools have not been explored. This cross-sectional study examined whether device-measured moderate-to-vigorous intensity physical activity and sedentary time are related to neural responses to visual food cues using functional magnetic resonance imaging. Fifty-one healthy adults (30 men, 21 women; mean ± SD: age 26 ± 6 years; body mass index 24.1 ± 3.0 kg/m2) underwent a functional magnetic resonance imaging scan after an overnight fast while viewing images of high/very high-energy density foods (HED), very low/low-energy density foods (LED) and non-food objects. Free-living moderate-to-vigorous intensity physical activity and sedentary time were measured for seven consecutive days using an ActiGraph wGT3X-BT and activPAL4 accelerometer, respectively. Associations of behavioural variables with brain food cue reactivity were examined in regression models controlling for physiological and behavioural covariates. After adjusting for age, sex, body mass index and device weartime, moderate-to-vigorous intensity physical activity was negatively associated with reactivity to LED versus non-food cues in the precentral gyrus, hippocampus, posterior insula, and amygdala, which may diminish inhibitory-related responses towards healthier lower energy value foods. Time spent in moderate-to-vigorous intensity physical activity was positively associated with reactivity to LED versus non-food cues in the dorsal striatum, a region implicated in food motivation. A positive association was identified between sedentary time and reactivity to HED versus non-food cues in the dorsal division of the posterior cingulate gyrus that has been implicated in attention allocation. These findings suggest that moderate-to-vigorous intensity physical activity may enhance the appeal of and motivation to consume LED foods, whereas sedentary time may promote attention towards HED foods, highlighting the potential for engaging in greater physical activity and less sedentary time to positively influence the central (brain) appetite control system.

Best practices for including sex as a variable in appetite research

Despite increasing recognition that sex is a critical variable in appetite research, many studies fail to include participants of both sexes, fail to consider reproductive physiology in participant selection, or include both sexes but fail to test for sex differences in outcomes. To help remedy this situation, this article seeks to engender enthusiasm for including sex as a variable in appetite research. We first illustrate some sex differences in healthy and disordered eating, including both male-female differences and differences across the menstrual cycle. We next provide methodological guidance for studies involving male and female participants around puberty, during reproductive adulthood, and during reproductive senescence. Studies in children ≥5 y of age should consider adrenarche and gonadarche. Appetite studies in girls and women following menarche and similarly aged males should consider the influences of sex-specific aspects the hypothalamic-pituitary-gonadal (HPG) axis function. The cyclicity of HPG function (i.e., the menstrual cycle) in girls and women presents the challenge of identifying of menstrual-cycle subphases, which are highly variable within and between individuals. Reproductive senescence refers to changes in HPG axis function that occur in both men and women beginning in mid-life. Current best practices involve consideration of hormone-assay methodology, experimental design, and statistical analyses. On the horizon are options based on wearable-sensors and nanotechnology. Well informed consideration of sex as a variable will accelerate progress in appetite research by increasing rigor, replicability, and relevance.

Impact of Different Low-Volume Concurrent Training Regimens on Cardiometabolic Health, Inflammation, and Fitness in Obese Metabolic Syndrome Patients

BACKGROUND/OBJECTIVES

Evidence supports the benefits of concurrent training (CT), which combines endurance and resistance exercises, for enhancing health and physical fitness. Recently, low-volume, time-efficient exercise approaches such as low-volume high-intensity interval training (LOW-HIIT), whole-body electromyostimulation (WB-EMS), and single-set resistance training (1-RT) have gained popularity for their feasibility and efficacy in improving various health outcomes. This study investigated the effects of low-volume CT, focusing on (1) whether exercise order affects cardiometabolic health, inflammation, and fitness adaptations and (2) which combination, LOW-HIIT plus WB-EMS or LOW-HIIT plus 1-RT, yields better results.

METHODS

Ninety-three obese metabolic syndrome (MetS) patients undergoing caloric restriction were randomly assigned to four groups performing the different low-volume CT protocols over 12 weeks. Outcomes included cardiometabolic, inflammatory, and fitness parameters.

RESULTS

In both combinations, no significant differences were found regarding exercise order. However, the pooled LOW-HIIT and 1-RT group achieved superior improvements in blood pressure, blood lipids, inflammation markers (CRP, hsCRP), the MetS severity score, and overall fitness compared to the LOW-HIIT and WB-EMS combination. Compared to previous studies using these modalities individually, LOW-HIIT plus 1-RT appeared to further reduce inflammation, whereas LOW-HIIT combined with WB-EMS was less effective for cardiometabolic health, potentially due to interference effects between modalities.

CONCLUSIONS

While LOW-HIIT plus WB-EMS appears to be a viable option for individuals unable to perform traditional resistance training, the findings suggest prioritizing LOW-HIIT plus 1-RT to maximize health outcomes. These findings highlight the importance of tailored exercise prescriptions and the need for further research into optimizing CT protocols for diverse populations.

Are post-exercise plasma glucose elevations involved in exercise-induced appetite suppression?

Changes in glucose and insulin are potentially involved in the appetite-regulatory effects of exercise considering their role post-prandially. The purpose of this study was to examine whether glucose and insulin play a role in post-exercise appetite regulation. Twelve participants (M = 8; 26 ± 5 years) completed 3 experimental sessions in a systematically rotated randomized crossover design: (1) no-exercise control (CTRL); (2) moderate-intensity continuous training (MICT; 30 min, 70% maximal oxygen consumption (V̇O2max)); and (3) sprint interval training (SIT; 4 × 30 s "all-out" sprints, interspersed with 4 min rest). Plasma glucose, insulin, acylated ghrelin, active peptide tyrosine tyrosine (PYY), active glucagon-like peptide-1 (GLP-1), and overall appetite perceptions were measured pre-exercise, 0, 30, 60, and 120 min post-exercise. Energy intake was recorded the day before, of, and after experimental sessions. Glucose was elevated 0 min post-exercise (p < 0.097, d > 0.52) compared to CTRL with no differences between exercise bouts. Acylated ghrelin was suppressed by MICT (60, 120 min) and SIT (0, 30, 60, 120 min; p < 0.080, d > 0.56) compared to CTRL, while also suppressed in SIT compared to MICT at 30, 60, 120 min (p < 0.026, d > 0.74). GLP-1 was elevated following MICT (0, 30, and 60 min) and SIT (60 min; p < 0.094, d > 0.53) compared to CTRL and following MICT compared to SIT (0 min; p = 0.005, d = 1.03). Overall appetite was suppressed by SIT post-exercise (p < 0.058, d > 0.61) compared to CTRL and MICT, and by MICT 0 min post-exercise compared to CTRL (p = 0.036, d = 0.71). There were no exercise effects on insulin, PYY, or free-living energy intake (p > 0.217, ηp 2 < 0.130). Glucose and insulin do not appear to play a role in exercise-induced appetite suppression.

Associations between sleep, energy balance, and obesity markers over 6 months in Black emerging adults-pilot study findings from the Sleep, Health Outcomes, and Body Weight (SHOW) study

Insufficient sleep (short sleep duration and poor sleep quality) is associated with obesity risk. Emerging adults (ages 18-28 years) have a greater risk of excess weight gain and insufficient sleep, and these risks are higher in Black individuals. Using a measurement burst design, we assessed associations between sleep with energy balance components and obesity marker changes over 6 months in 15 Black emerging adults (12 females; age: 21 ± 2.5 years; body mass index: 25.7 ± 4.5 kg/m2; body fat: 25.8 ± 11.9%). Since our sample was predominantly female (80%), we repeated our analyses for females only. Participants completed the following measurements at baseline (BLN) and 6 months later (6MO): 7 days of actigraphy-based sleep and physical activity energy expenditure (EE) and 2 nights of in-home polysomnography-based sleep; resting EE and thermic effect of food with indirect calorimetry; ad libitum energy intake (EI) via self-reported methods over 4 days and directly measured over 3 days with provided meals. Body weight (2.6 kg, p = 0.01) and waist circumference (2.4 cm, p = 0.03) increased from BLN to 6MO. Changes in actigraphy-based sleep duration were associated with changes in body weight (β = 0.03, standard error (SE) = 0.02, p = 0.04) and fat mass (β = 0.07, SE = 0.03 p = 0.03) in females only. Greater rapid eye movement sleep duration was associated with increases in resting EE (β = 2.24, SE = 0.84, p = 0.02). Greater slow-wave sleep was associated with increases in self-reported EI (β = 18.34, SE = 4.7, p < 0.01). Sleep may impact components of energy balance and risk of weight gain in Black emerging adults. Additional research is needed to confirm our pilot findings.

Predictive equation derived from 6,497 doubly labelled water measurements enables the detection of erroneous self-reported energy intake

Nutritional epidemiology aims to link dietary exposures to chronic disease, but the instruments for evaluating dietary intake are inaccurate. One way to identify unreliable data and the sources of errors is to compare estimated intakes with the total energy expenditure (TEE). In this study, we used the International Atomic Energy Agency Doubly Labeled Water Database to derive a predictive equation for TEE using 6,497 measures of TEE in individuals aged 4 to 96 years. The resultant regression equation predicts expected TEE from easily acquired variables, such as body weight, age and sex, with 95% predictive limits that can be used to screen for misreporting by participants in dietary studies. We applied the equation to two large datasets (National Diet and Nutrition Survey and National Health and Nutrition Examination Survey) and found that the level of misreporting was >50%. The macronutrient composition from dietary reports in these studies was systematically biased as the level of misreporting increased, leading to potentially spurious associations between diet components and body mass index.

Water intake in athletes: Agreement between food records and isotope-dilution methods

BACKGROUND

Although water intake (WI) is commonly estimated through self-reporting, its inaccuracy is reported. Water turnover (rH2O)-derived WI is the reference method; however, it is costly. The study aimed to validate alternative methods for determining WI in a group of athletes.

METHODS

Eighty-two athletes (20.4 ± 5.1 years; 28 females) were included in this cross-sectional validation study. Doubly labelled water (DLW) determined rH2O and rH2O-derived WI by subtracting metabolic, transcutaneous, and inspired water from rH2O (reference). The rH2O components were determined by alternative approaches: i) average values of macronutrients instead of individual food records (DLW-derived WI); ii) estimating total energy expenditure (TEE) and rCO2 through a predictive equation instead of DLW (2H-derived WI); iii) estimating rH2O by prediction equation (equation-derived WI). Food records were employed to determine WI (food record-derived WI).

RESULTS

Only DLW-derived WI showed no significant differences compared to reference in both sexes (females: 2 mL/day, p = 0.183; males: -4 mL/day, p = 0.118). 2H-derived WI showed significant but small differences (females: 23 mL/day, p = 0.001; males: 32 mL/day, p < 0.001) while food record-derived WI showed the largest differences (females: -924 mL/day, p < 0.001; males: -1504 mL/day, p < 0.001). DLW-derived and 2H-derived WI showed good performance [r2 > 0.987 and concordance correlation coefficient (CCC) > 0.993], while food record-derived WI showed poor performance [r2 < 0.031 and CCC < 0.133)].

CONCLUSION

Although some alternative approaches provide adequate estimates, DLW- and 2H-derived WI are the only valid methods to determine WI in our sample of competitive athletes. These approaches are less costly and could contribute to the development of WI guidelines for athletes. Food records underestimate WI, but evidence-based recommendations could reduce misrecordings.

Greater lactate accumulation does not alter peripheral concentrations of key appetite-regulating neuropeptides

The potential mechanisms involved in lactate's role in exercise-induced appetite suppression require further examination. We used sodium bicarbonate (NaHCO3) supplementation in a double-blind, placebo-controlled, randomized crossover design to explore lactate's role on neuropeptide Y (NPY), agouti-related peptide (AgRP), and alpha-melanocyte-stimulating hormone (α-MSH) concentrations. Twelve adults (7 males; 24.2 ± 3.4 kg·m-2; 42.18 ± 8.56 mL·kg-1·min-1) completed two identical high-intensity interval training sessions following ingestion of NaHCO3 (BICARB) or sodium chloride (PLACEBO) pre-exercise. Blood lactate, acylated ghrelin, NPY, AgRP, α-MSH, and appetite perceptions were measured pre-exercise, 0-, 30-, 60-, and 90-min postexercise. Free-living energy intake (electronic food diaries) was measured the day before, of, and after each experimental session. In BICARB, blood lactate was greater postexercise (P < 0.002, d > 0.70), though acylated ghrelin was similar (P = 0.075, [Formula: see text] = 0.206) at all time points postexercise (P > 0.034, d < 0.22). NPY (P = 0.006, [Formula: see text] > 0.509) and AgRP (P < 0.001, [Formula: see text] > 0.488) had main effects of time increasing following exercise and returning to baseline, with no differences between sessions (NPY: P = 0.0.192, [Formula: see text] = 0.149; AgRP: P = 0.422, [Formula: see text] = 0.060). α-MSH had no main effect of time (P = 0.573, [Formula: see text] = 0.063) or session (P = 0.269, [Formula: see text] = 0.110). Appetite perceptions were similar during BICARB and PLACEBO (P = 0.007, d = 0.28), increasing in both sessions postexercise (P < 0.088, d > 0.57). Energy intake had a main effect of day (P = 0.025, [Formula: see text] = 0.825), where the experimental session day was greater than the day before (P = 0.010, d = 0.59) with no other differences between days (P > 0.260, d < 0.38). The lower accumulation of lactate than our previous work did not generate exercise-induced appetite suppression as there were no differences in acylated ghrelin, appetite perceptions, or peripheral concentrations of neuropeptides.NEW & NOTEWORTHY Current evidence supports lactate's role in exercise-induced appetite suppression. Here, we demonstrate a smaller degree of lactate accumulation with sodium bicarbonate ingestion and HIIT than our previous work and no subsequent suppression of acylated ghrelin concentrations, subjective appetite perceptions, or peripheral concentrations of neuropeptides. These results suggest either changes in central appetite-regulating neuropeptides are not reflected peripherally or the smaller magnitude of lactate accumulation did not generate exercise-induced appetite suppression as seen previously.

Effectiveness of Nutrition Education on Weight Loss and Body Metrics Among Obese Adults: An Interventional Study

Background Obesity has detrimental personal, societal, and economic consequences and raises the risk of developing chronic diseases such as diabetes and cardiovascular diseases. Diet and exercise behaviors are frequently the focus of weight loss programs. Effective nutrition education is associated with a reduced risk of chronic diseases and body weight management. Individualized lifestyle and counseling sessions with follow-ups reduce weight loss compared to single combined sessions. Objectives The objective of this study was to assess the effectiveness of nutrition education intervention on weight loss among adults aged 18-40 years in Lahore through an interventional study. Methods This study was conducted in Lahore. According to the inclusion criteria, overweight/obese (Body Mass Index (BMI) ≥ 23 kg/m²), young (18-40 years old) men and women were part of this study. A total of 50 participants were randomized into two groups, one as the control group and the other one as the intervention group. Group counseling was provided to the control group. The intervention group was assessed individually through follow-ups for 3 months of online and on-campus sessions. Data was collected at four intervals at baseline, month 1, month 2, and month 3 through a self-administered assessment form. Data was analyzed using the statistical package for social science, SPSS version 25 (IBM Corp., Armonk, USA). Results Out of the 50 participants, 54% (27) were women while 46% (23) were men (mean age 29.90, SD = 6.26, BMI at baseline 32.18 kg/m², 26. 49 kg/m²), and randomized by a blinded researcher. At three months, the mean differences in BMI, waist circumference, waist-to-hip ratio, and body fat percentage between the groups were 3 kg (23.44 ± 0.58, 95% CI 22.86-24.02), 33.90 cm (95% CI 32.50-35.30), 0.86 (95% CI 0.74-0.98), and 24.79% (95% CI 18.00-31.58), respectively, in favor of the intervention group (p < 0.005).  Conclusion This study demonstrates that a structured dietary intervention combined with physical activity guidance leads to significant weight loss and improved body composition in obese adults. These findings support the effectiveness of comprehensive weight loss strategies for managing obesity.

Sleep apnoea symptoms and sleepiness associate with future diet quality: a prospective analysis in the Bogalusa Heart Study

Sleep apnoea is a known risk factor for cardiometabolic diseases (CMD), but it is unknown whether sleep apnoea or its symptoms contribute to increased CMD through an association with diet quality. This study assessed the association between sleep apnoea symptoms on future diet quality in the Bogalusa Heart Study (BHS). This prospective study included 445 participants who completed a sleep apnoea questionnaire in 2007-2010 and a FFQ in 2013-2016 (mean follow-up: 5·8 years; age 43·5 years; 34 % male; 71 % White/29 % Black persons). Diet quality was measured with the Alternate Healthy Eating Index (AHEI) 2010, the Healthy Eating Index (HEI) 2015 and the alternate Mediterranean diet score. Adjusted mean differences in dietary patterns by sleep apnoea risk, excessive snoring and daytime sleepiness were estimated with multivariable linear regression. Models included multi-level socio-economic factors, lifestyle and health characteristics including BMI, physical activity and depressive symptoms. Those with high sleep apnoea risk, compared with low, had lower diet quality 5·8 years later (percentage difference in AHEI (95 % CI -2·1 % (-3·5 %, -0·7 %)). Daytime sleepiness was associated with lower diet quality. After adjusting for dietary pattern scores from 2001 to 2002, having high sleep apnoea risk and excessive sleepiness were associated with 1·5 % (P < 0·05) and 3·1 % (P < 0·001) lower future AHEI scores, respectively. These findings suggest that individuals with sleep apnea or excessive sleepiness should be monitored for diet quality and targeted for dietary interventions to improve CMD risk.

Energy Balance and Dietary Intake in Young Rugby Players during a Pre-Season Micro-Cycle: A Cluster Analysis

Rugby players must develop excellent levels of conditioning during adolescence. However, this pivotal period of life is also characterized by a surge in biological growth, which further increases the energy and nutritional requirements of this population. This study examined within-individual differences in energy intake (EI) and energy balance (EB) of 46 young rugby players during a pre-season micro-cycle. Two clusters were identified with significantly different characteristics and EB states, suggesting that young rugby players adjust their EI to match their body composition goals. The first cluster is characterized by players with a low body fat% (12.87 ± 2.53). They had a positive EB (330 ± 517 kcal), suggesting a goal of increasing muscle mass. Conversely, the second cluster is characterized by a higher body fat% (23.1 ± 1.6, p < 0.005) and reported a negative, lower EB (-683 ± 425 kcal, p < 0.005), suggesting a goal focused on reducing fat mass. Although our study provides more optimistic results than previous ones regarding the high risk of inadequate EI in young rugby players, we emphasize the importance of rigorous nutritional support, especially for players aiming to lose weight, to avoid severe caloric restriction, as well as the downstream effects of such practices on their nutritional status, given the higher risk of macro- (e.g., CHO < 6 g/kg/d) and micronutrient (e.g., iron < 11 mg/d, calcium < 1300 mg/d, vitamin D < 5 mg/d) deficiencies.

Effect of Early Time-Restricted Eating on Metabolic Markers and Body Composition in Individuals with Overweight or Obesity

This study aimed to evaluate the effect of early time-restricted eating (eTRE) on metabolic markers and body composition in individuals with overweight or obesity. Seventeen subjects completed a randomized, crossover, and controlled clinical trial. Twelve women and five men participated, with a mean age of 25.8 ± 10.0 years and a BMI of 32.0 ± 6.3 kg/m2. The eTRE intervention included 16 h of fasting (3:00 pm to 7:00 am) and 8 h of ad libitum eating (7:00 am to 03:00 pm) (16:8). The trial included four weeks of interventions followed by a four-week washout period. Body weight, waist and hip circumferences, and body composition measurements were taken. Additionally, a venous blood sample was collected for biochemical determinations. In a before-after analysis, eTRE induced a reduction in BW and BMI in women but this was not significant when compared to the control group. eTRE did not modify any other anthropometric measurements, fasting biochemical parameters, glycemic and insulinemic responses, blood pressure, or subjective appetite. In conclusion, eTRE did not induce beneficial effects on the glycemic and lipid metabolisms, body composition, subjective appetite, or blood pressure. These findings may be attributed to the special characteristics of the population and the short intervention period.

Guilt by association: Plant-based foods can be incorporated into both healthy and unhealthy plant-based diet indices associated with coronary heart disease

Background

One approach to test for differential associations between plant foods with health uses a scoring approach: foods categorized into animal or 'healthy' plant-based or 'unhealthy' plant-based groups to construct a plant-based diet index (PDI), healthy PDI (hPDI), and unhealthy PDI (uPDI).

Objective

To evaluate robustness of associations between diet indices and incident coronary heart disease (CHD) risk when recategorizing food groups in indices.

Methods

Using REasons for Geographic and Racial Differences in Stroke (REGARDS) data, we replicated a published use of the scoring approach. Using Cox proportional hazards regression, we assessed ramifications of the following on associations between diet indices and CHD risk: 1) reconfiguring foods within and among food groups, using potatoes as an example, 2) leave-one-out analysis for each of 12 plant-based food groups, and 3) agnostically redefining each food group as 'healthy' or 'unhealthy'.

Results

Over 153,286 person-years of follow-up, there were 868 cases of CHD. Replication analyses did not reach statistical significance. General patterns of magnitude of hazard ratios (HRs) in replication and reconfiguration models were PDI HRs < hPDI HRs < uPDI HRs for women, and hPDI < PDI < uPDI for men. Five models reconfiguring potatoes resulted in small, varied differences in PDI, hPDI, and uPDI associations. Leave-one-out analyses resulted in greater variation of associations between indices and CHD. In agnostic models, each plant-based food group was classified in indices as 'healthy' and 'unhealthy' with statistically significant beneficial or deleterious associations with CHD. Averaged over 4,096 models, HRs' shifts were small when food groups were moved between 'healthy' and 'unhealthy'.

Conclusion

Statistically significant associations between hPDI, uPDI, and PDI and incident CHD were not replicated. Small perturbations of the scoring approach had varied impacts on HRs. Agnostically constructing diet indices demonstrated the potential for guilt (or benefit) by association: any of the food groups we studied could be categorized with others in an index showing beneficial or deleterious associations.

Secular trends and determinants of ad libitum energy intake measured in a research setting from 1999-2020

Introduction

Historically, secular and seasonal trend analyses have been examined using self-report measures of intake. Rarely are objective measures and known determinants of dietary intake used in these analyses. Our objective was to quantify the seasonal and secular differences in an objective ad libitum intake paradigm while considering the contribution of determinants, such as fat-free mass (FFM) index and spontaneous physical activity (SPA) limited to the restricted space of a whole-room calorimeter.

Methods

For this study, recruitment of N = 292 healthy, diabetes free, adults occurred from 1999 to 2020. Assessment during their 10-day stay included body composition (by DXA), SPA (by an approximately 24-h stay in whole-room calorimetry), and ad libitum intake (by a vending machine for 3 days). This secondary analysis used general linear models (GLM) to investigate secular and seasonal differences while adjusting for sex, age, FFM index, FM (fat mass) index, SPA, and race/ethnicity.

Results

FFM index and SPA were positively associated with all intake measures (p < 0.05). In all adjusted seasonal models, season did not affect intake. Adjusted secular trends models (kcals/year) demonstrated a decrease in total kcals (β = -55), intake as percent weight maintaining energy needs (β = -2), protein kcals (β = -10), fat kcals (β = -27), and carbohydrates kcals (β = -22) (all p < 0.05). After further adjustment for SPA, significance remained in all intake measures (p < 0.05). Secular trends in body composition revealed no changes in weight, BMI, and percent body fat (all p > 0.20).

Discussion

Our results indicate that over time, ad libitum intake decreased in this controlled research setting and remained significant even after accounting for positive determinants of intake. A significant ad libitum decrease, coupled with no change in body composition, may highlight a participant bias toward calorie restriction in a controlled setting over time and deserves further investigation.

Misstatements, misperceptions, and mistakes in controlling for covariates in observational research

We discuss 12 misperceptions, misstatements, or mistakes concerning the use of covariates in observational or nonrandomized research. Additionally, we offer advice to help investigators, editors, reviewers, and readers make more informed decisions about conducting and interpreting research where the influence of covariates may be at issue. We primarily address misperceptions in the context of statistical management of the covariates through various forms of modeling, although we also emphasize design and model or variable selection. Other approaches to addressing the effects of covariates, including matching, have logical extensions from what we discuss here but are not dwelled upon heavily. The misperceptions, misstatements, or mistakes we discuss include accurate representation of covariates, effects of measurement error, overreliance on covariate categorization, underestimation of power loss when controlling for covariates, misinterpretation of significance in statistical models, and misconceptions about confounding variables, selecting on a collider, and p value interpretations in covariate-inclusive analyses. This condensed overview serves to correct common errors and improve research quality in general and in nutrition research specifically.

Should carbohydrate-modified diets be the first option for weight loss in people with impaired glucose metabolism? A scoping review

While the "precision nutrition" movement is at an early stage of development, several investigations have compared low-fat versus carbohydrate (CHO)-modified diets (i.e., low-or-reduced-CHO, low glycemic index/load diets, and high-fiber) in people with normal versus impaired glucose metabolism. The purpose of this scoping review was to summarize evidence in support of the hypothesis that CHO-modified diets are more effective for weight loss among people with impaired glucose metabolism. Fifteen articles were included in this review: seven retrospective analyses of randomized clinical trials and eight prospective randomized clinical trials with prespecified hypotheses related to a diet (low-fat vs. CHO-modified) × phenotype (normal vs. impaired) interaction. Evidence in support of the hypothesis was identified in six of seven retrospective and three of eight prospective studies, which led to a recommendation of CHO-modified diets as a first-line option for people with impaired glucose metabolism. However, the evidence in support of this recommendation is relatively weak, and dietary prescriptions should consider additional contextual information that may influence overall dietary adherence. Additional and rigorous research using innovative randomized experimental approaches is needed for stronger dietary weight loss recommendations based on pretreatment glycemic status.

Low- and high-load resistance training exercise to volitional fatigue generate exercise-induced appetite suppression

Research on exercise-induced appetite suppression often does not include resistance training (RT) exercise and only compared matched volumes.

PURPOSE

To compare the effects of low-load and high-load RT exercise completed to volitional fatigue on appetite-regulation.

METHODS

11 resistance-trained males (24 ± 2 y) completed 3 sessions in a crossover experimental design: 1) control (CTRL); 2) RT exercise at 30% 1-repetition maximum (RM); and 3) RT exercise at 90% 1-RM. RT sessions consisted of 3 sets of 5 exercises completed to volitional fatigue. Acylated ghrelin, active glucagon-like peptide-1 (GLP-1), active peptide tyrosine (PYY), lactate, and subjective appetite perceptions were measured pre-exercise, 0-, 60-, and 120-min post-exercise. Energy intake was recorded the day before, of, and after each session.

RESULTS

Lactate was elevated following both 30% (0-, 60-, 120-min post-exercise) and 90% (0-, 60-min post-exercise; P < 0.001, d > 3.92) versus CTRL, with 30% greater than 90% (0-min post-exercise; P = 0.011, d = 1.14). Acylated ghrelin was suppressed by 30% (P < 0.007, d > 1.22) and 90% (P < 0.028, d > 0.096) post-exercise versus CTRL, and 30% suppressed concentrations versus 90% (60-min post-exercise; P = 0.032, d = 0.95). There was no effect on PYY (P > 0.171, ηp2 <0.149) though GLP-1 was greater at 60-min post-exercise in 90% (P = 0.052, d = 0.86) versus CTRL. Overall appetite was suppressed 0-min post-exercise following 30% and 90% versus CTRL (P < 0.013, d > 1.10) with no other differences (P > 0.279, d < 0.56). There were no differences in energy intake (P > 0.101, ηp2 <0.319).

CONCLUSIONS

RT at low- and high-loads to volitional fatigue induced appetite suppression coinciding with changes in acylated ghrelin though limited effects on anorexigenic hormones or free-living energy intake were present.

ONE QUALITY concept: a narrative perspective to unravel nutritional challenges, controversies, and the imperative need of transforming our food systems

Ensuring a healthy and sustainable diet for all should be a global priority, and to achieve this goal the food system requires substantial changes. Adopting a one-size-fits-all approach is not feasible, and we need to consider the cultural particularities of each geography and not try to export models that work in one place but may be unsustainable in others. Our discussion will center on two key aspects within this overarching process: (a) the combination of a rigorous evidence-based approach with existing or proposed Nutritional Guidelines and policies required to realize the "ONE HEALTH" and "ONE QUALITY" concepts. Examining the Mediterranean diet and the latest findings on saturated fats will aid us in comprehending the necessary paradigm shift required to formulate new guidelines with substantial impact in preventing the rising prevalence of Non-Communicable Diseases worldwide; (b) the adequacy and scope of the data bank necessary to develop a global, science-based approach.

The impact of body composition on the degree of misreporting of food diaries

BACKGROUND/OBJECTIVES

Accurate assessments of energy intake (EI) are needed in lifestyle interventions to guarantee a negative energy balance (EB), thereby losing weight. This study aimed (1) to compare objectively measured and self-reported EI and (2) to determine the predictors of underreporting divided by sex, adiposity and BMI category.

METHODS

Seventy-three participants [mean (SD): 43.7 (9.2) years, BMI = 31.5 (4.5) kg/m2, 37% females] of the Champ4Life intervention were included in this study. EI was measured using the "intake-balance method" and self-reported through 3-day food records. Fat mass (FM) and fat-free mass (FFM) were measured by dual-energy X-ray absorptiometry. Bland-Altman analysis was performed to compare both EI assessments.

RESULTS

Self-reported EI was lower than measured EI during both neutral (-355 kcal/d) and negative EB (-570 kal/day). While no significant trends were observed for EI evaluation in either neutral (p = 0.315) or negative EB (p = 0.611), limits of agreement were wide (-1720 to 1010 and -1920 to 779 kcal/day, respectively). In females, the degree of misreporting (kcal/day and %) was predicted by weight (p = 0.032 and p = 0.039, respectively) and FM (p = 0.029 and p = 0.037, respectively). In males, only BMI (p = 0.036) was a predictor of misreporting (kcal/day).

CONCLUSION

Self-reported EI did not agree with measured EI. Our results show that larger body size was associated with higher levels of underestimation for EI (females only). Nevertheless, misreporting EI is a complex issue involving more associations than merely body composition. A deeper understanding could inform counseling for participants filling out food records in other to reduce misreporting and improve validity.

Ten weeks of low-volume walking training improve cardiometabolic health and body composition in sedentary postmenopausal women with obesity without affecting markers of bone metabolism

This study aimed to determine the effects of walking exercise to induce a mild energy deficit and to improve body composition and metabolic status in postmenopausal women (PMW) with obesity as means of minimizing endocrine disruption and maintaining bone health. Twenty-four PMW with obesity (age: 55.0 ± 3.7 y, BMI: 32.9 ± 4.2 kg/m2, percent body fat: 46.2 ± 3.6%) were randomly assigned into either exercise (n = 12) or control (n = 12) groups. Exercise group participated in a-10 week supervised progressive walking programme   and control group maintained regular habits. Pre- and post-training assessments included body composition, bone mass, peak oxygen uptake (V ˙ O2peak), osteocalcin, bone alkaline phosphatase (BAP), type I collagen cross-linked C-telopeptide (CTX)glucose, glycated haemoglobin (HbA1c)), leptin and adiponectin. Results: Following the training program, body weight (2.6%; p < 0.001), fat mass (4.5%; p = 0.002), resting glucose (6.8%; p = 0.017), and HbA1c (3.7%; p = 0.047) decreased, while relative V ˙ O2peak (16%; p < 0.001) increased in the exercise group. Leptin, adiponectin, CTX, osteocalcin or BAP did not change in either group. In conclusion, small dose of aerobic exercise improves key markers of metabolic health in PMW with obesity without negatively affecting markers of bone metabolism.

Twenty-Four-Hour Urinary Sugars Biomarker in a Vending Machine Intake Paradigm in a Diverse Population

Accurately measuring dietary sugars intake in large-scale epidemiological studies is necessary to understand dietary sugars' true impact on health. Researchers have developed a biomarker that can be used to assess total sugars intake. Our objective is to test this biomarker in diverse populations using an ad libitum intake protocol. Healthy adult participants (n = 63; 58% Indigenous Americans/Alaska Natives; 60% male; BMI (mean ± SD) = 30.6 ± 7.6 kg.m2) were admitted for a 10-day inpatient stay. On day 2, body composition was measured by DXA, and over the last 3 days, ad libitum dietary intake was measured using a validated vending machine paradigm. Over the same days, participants collected daily 24 h urine used to measure sucrose and fructose. The 24 h urinary sucrose and fructose biomarker (24hruSF) (mg/d) represents the sum of 24 h urinary sucrose and fructose excretion levels. The association between the 3-day mean total sugars intake and log 24uSF level was assessed using the Pearson correlation. A linear mixed model regressing log-biomarker on total sugars intake was used to investigate further the association between biomarker, diet, and other covariates. Mean (S.D.) total sugars intake for the group was 197.7 g/d (78.9). Log 24uSF biomarker was moderately correlated with total sugars intake (r = 0.33, p = 0.01). In stratified analyses, the correlation was strongest in females (r = 0.45, p = 0.028), the 18-30 age group (r = 0.44, p = 0.079), Indigenous Americans (r = 0.51, p = 0.0023), and the normal BMI category (r = 0.66, p = 0.027). The model adjusted for sex, age, body fat percent, and race/ethnicity demonstrated a statistically significant association between 24uSF and total sugars intake (β = 0.0027, p < 0.0001) and explained 31% of 24uSF variance (marginal R2 = 0.31). Our results demonstrated a significant relationship between total sugars intake and the 24uSF biomarker in this diverse population. However, the results were not as strong as those of controlled feeding studies that investigated this biomarker.

Psychometric validation of four-item exercise identity and healthy-eater identity scales and applications in weight loss maintenance

BACKGROUND

Identifying as someone who engages in health promoting behaviors like healthy eating and exercising may be associated with sustained engagement in those behaviors, but reliable and valid instruments are needed to improve the rigor of this research. Two studies were conducted to (1) examine the psychometric properties of a four-item exerciser identity measure (4-EI) and an adapted healthy-eater identity measure (4-HEI) and (2) examine differences in identity strengths across categories of weight loss success.

METHODS

Data from 1,709 community dwelling adults in the International Weight Control Registry (IWCR) were used. A random half of the sample was used to assess the proposed unidimensional factor structure of the 4-EI and 4-HEI and examine convergent and discriminant validity using Spearman rank-order correlations. One-way ANOVA was used in the other random half of the sample to compare 4-EI and 4-HEI scores (-3 to + 3) across three self-defined weight loss categories ('Successful', 'Regain', and 'Unsuccessful') and those maintaining ≥ 5% weight loss for > 1 year vs. not.

RESULTS

Results support the unidimensional factor structure with all four items (eigenvalue scores > 2.89) as well as convergent and discriminant validity for both measures. Exercise identity was strongly correlated with self-reported physical activity (r (735) = 0.52, p <.001) and measures of autonomous motivation. Healthy eating identity was moderately correlated with cognitive restraint in eating (r (744) = 0.42, p <.001) and other measures predictive of eating behavior. 4-EI and 4-HEI are stronger in Successful (4-EI: M = 0.90, SD = 1.77; 4-HEI: M = 1.56 SD = 1.37) vs. Regain (4-EI: M=-0.18, SD = 1.68; 4-HEI: M =.57, SD = 1.48) and Unsuccessful (4-EI:M=-0.28, SD = 1.62; 4-HEI: M = 0.51, SD = 1.33) and those maintaining ≥ 5% weight loss (4-EI:M = 0.47, SD = 1.78; 4-HEI: M = 1.13, SD = 1.49) vs. not (4-EI:M=-0.27, SD = 1.66; 4-HEI: M = 0.53, SD = 1.47), p's < 0.001.

CONCLUSIONS

The 4-EI and 4-HEI have acceptable psychometric properties and can advance understanding of the role of identity in exercise and dietary behaviors and weight loss maintenance.

TRIAL REGISTRATION

The parent observational study, International Weight Control Registry (IWCR), for these sub-studies is registered in ClinicalTrials.gov (NCT04907396).

Interindividual variability in energy intake and expenditure during a weight loss intervention

INTRODUCTION

Behavioral compensations may occur as a response to a negative energy balance. The aim of this study was to explore the associations between changes in energy intake (EI) and changes in physical activity (PA, min/day; kcal/d) as a response to a weight loss (WL) intervention and to understand if interindividual differences occur in EI and energy expenditure (EE).

METHODS

Eighty-one participants [mean (SD): age = 42.8 (9.4)y, BMI = 31.2 (4.4)kg/m2, 37% females] divided in intervention (IG, n = 43) and control group (CG, n = 38) were included. The IG underwent a moderate energy restriction (300-500 kcal/d). EI was measured through the intake-balance method. Non-exercise PA (NEPA) and exercise (through logbook) were assessed by accelerometery. The EE in NEPA (NEAT) and in exercise (EiEE) was calculated by applying the Freedson Combination'98 algorithm over the time spent in these activities. Pearson correlations were performed in IG to examine associations between EE components, EI and body composition. To understand if interindividual differences were observed, the SD of individual response (SDIR) and the smallest worthwhile change (SWC, SDbaselineCG×0.2) were calculated.

RESULTS

Changes in EI [Δ EI, (kcal/d)] was negatively associated with Δ exercise (min/d:r = -0.413, p = 0.045; %:r = -0.846, p = 0.008) and with Δ EiEE (kcal/d:r = -0.488, p = 0.016; %:r = -0.859, p = 0.006). A negative correlation was found between Δ sedentary time and Δ NEPA (min/d:r = -0.622, p = 0.002; %:r = -0.487, p = 0.018). An interindividual variability was found for EI(SDIR = 151.6, SWC = 72.3) and EE (SDIR = 165, SWC = 134).

CONCLUSIONS

Decreases in EI were not associated to compensatory responses such as decreases in PA and/or increases in sedentary time. Interindividual variability was found for EI and EE. Nevertheless, behavioral compensations and the interindividual variability should be considered when implementing WL interventions, to increase the likelihood of achieving sustainable results. (clinicaltrials.gov ID: NCT03031951).

The Validity and Feasibility of Utilizing the Photo-Assisted Dietary Intake Assessment among College Students and Elderly Individuals in China

Dietary assessments hold significant importance within the field of public health. However, the current methods employed for dietary assessments face certain limitations and challenges that necessitate improvement. The aim of our study was to develop a reliable and practical dietary assessment tool known as photo-assisted dietary intake assessment (PAD). In order to evaluate its validity, we conducted an analysis on a sample of 71 college students' dinners at a buffet in a canteen. We compared estimates of food weights obtained through the 24-h recall (24 HR) or PAD method with those obtained through the weighing method; we also evaluated the feasibility of PAD for recording dinner intakes among a sample of college students (n = 76) and elderly individuals (n = 121). In addition, we successfully identified the dietary factors that have a significant impact on the bias observed in weight estimation. The findings of the study indicated that the PAD method exhibited a higher level of consistency with the weighing method compared to the 24 HR method. The discrepancy in D% values between cereals (14.28% vs. 40.59%, P < 0.05), vegetables (17.67% vs. 44.44%, P < 0.05), and meats (14.29% vs. 33.33%, P < 0.05) was clearly apparent. Moreover, a significant proportion of the food mass value acquired through the PAD method fell within the limits of agreement (LOAs), in closer proximity to the central horizontal line. Furthermore, vegetables, cereals, eggs, and meats, for which the primary importance lies in accuracy, exhibited a considerably higher bias with the 24 HR method compared to the PAD method (P < 0.05), implying that the PAD method has the potential to mitigate the quality bias associated with these food items in the 24 HR method. Additionally, the PAD method was well received and easily implemented by the college students and elderly individuals. In conclusion, the PAD method demonstrates a considerable level of accuracy and feasibility as a dietary assessment method that can be effectively employed across diverse populations.

Short-Term Effect of a Health Promotion Intervention Based on the Electronic 12-Hour Dietary Recall (e-12HR) Smartphone App on Adherence to the Mediterranean Diet Among Spanish Primary Care Professionals: Randomized Controlled Clinical Trial

BACKGROUND

The World Health Organization has called for addressing the growing burden of noncommunicable diseases (NCDs) by promoting healthy lifestyles among the population. Regarding patient health, primary care professionals (PCPs) are the first line of care who can positively influence patients' behavior and lifestyle habits. However, a significant percentage of PCPs do not lead a healthy lifestyle. Therefore, addressing their health behaviors may be the key to substantially increasing health promotion advice in general practice. The Mediterranean diet has been extensively studied, and there is strong evidence of it being a dietary pattern for the prevention of NCDs, in addition to its significant environmental, sociocultural, and local economics benefits.

OBJECTIVE

This study focused only on the dietary aspect of the PCPs' lifestyle. The primary objective was to evaluate the effect of using the Electronic 12-Hour Dietary Recall (e-12HR) smartphone app to improve diet, specifically to promote adherence to the Mediterranean diet (AMD), among PCPs. The secondary objectives were to establish the usability of the e-12HR app and to determine AMD among PCPs.

METHODS

An individual-level randomized, controlled, and single-blind clinical trial was conducted with 2 parallel groups: a control group (CG), using the nonfeedback version of the e-12HR app, and an intervention group (IG), using the feedback version of the e-12HR app. The level of human involvement was fully automated through the use of the app. There was a 28-day follow-up period. Participants were PCPs (medicine or nursing) recruited offline at one of the selected primary care centers (Andalusia, Spain, Southern Europe), of both sexes, over 18 years old, possessing a smartphone, and having smartphone literacy.

RESULTS

The study response rate was 73% (71 of 97 PCPs), with 27 (38%) women and 44 (62%) men: 40 (56%) PCPs in the CG and 31 (44%) in the IG. At baseline, AMD was medium (mean Mediterranean Diet Serving Score [MDSS] index 9.45, range 0-24), with 47 (66%) PCPs with a medium/high MDSS index. There were significant statistical improvements (CG vs IG, in favor of the IG) at week 4 (no significant statistical differences at baseline): +25.6% for the MDSS index (P=.002) and +213.1% for the percentage with a medium/high MDSS index (P=.001). In relation to specific food groups, there were significant statistical improvements for fruits (+33.8%, P=.02), vegetables (+352%, P=.001), nuts (+184%, P=.02), and legumes (+75.1%, P=.03). The responses to the usability rating questionnaire were satisfactory.

CONCLUSIONS

The results support recommending the use of the e-12HR app as a tool to contribute to improving diet and preventing NCDs among PCPs, while positively influencing patient dietary behavior and preventing diet-related NCDs among patients.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05532137; https://clinicaltrials.gov/study/NCT05532137.

Meat consumption & positive mental health: A scoping review

The objective of this scoping review was to examine the breadth of the existing literature on the relation between meat consumption or meat abstention and positive psychological functioning. In April 2022, we conducted a systematic search of online databases (PubMed, PsycINFO, CINAHL Plus, Medline, Cochrane Library, and Web of Science) for primary research examining positive psychological functioning in meat consumers and those who abstain from meat. Thirteen studies met the inclusion/exclusion criteria, representing 89,138 participants (54,413 females and 33,863 males) with 78,562 meat consumers and 10,148 meat abstainers (13-102 years) from multiple geographic regions. The primary outcomes were life satisfaction, "positive mental health", self-esteem, and vigor. The secondary outcomes were "meaning in life", optimism, positive emotions, and psychological well-being. Eight of the 13 studies demonstrated no differences between the groups on positive psychological functioning, three studies showed mixed results, and two studies showed that compared to meat abstainers, meat consumers had greater self-esteem, "positive mental health", and "meaning in life". Studies varied substantially in methods and outcomes. Although a small minority of studies showed that meat consumers had more positive psychological functioning, no studies suggested that meat abstainers did. There was mixed evidence for temporal relations, but study designs precluded causal inferences. Our review demonstrates the need for future research given the equivocal nature of the extant literature on the relation between meat consumption and meat abstention and positive psychological functioning.

Do macronutrient intakes affect obesity indices in Jordanian adults?

OBJECTIVE

To determine whether macronutrient intake is associated with novel obesity indices, including the conicity index (CI), body adiposity index (BAI), abdominal volume index (AVI), body roundness index (BRI), and weight-adjusted-waist index (WWI).

METHODOLOGY

A cross-sectional survey was conducted with 491 adults (344 males and 147 females) working at different universities in Jordan (July-December 2019). Daily intake of energy (kcal), carbohydrates (g), protein (g), and fat (g) was obtained using 24-h recalls collected over 2 days. Additionally, obesity indices were calculated.

RESULTS

Regardless of sex, energy, and carbohydrate intakes had a moderately significant positive association, whereas protein and fat intakes had a weakly significant association with BAI, AVI, and BRI. CI and WWI showed a weakly significant association with all macronutrients in males, a moderate correlation with energy and carbohydrate intake, and a weak association with fat and protein intake in females. Male participants had significant increases in the CI (T1 = 1.29 ± 0.01 vs. T3 = 1.36 ± 0.01, p = .018), AVI (T1 = 17.96 ± 0.52 vs. T3 = 22.81 ± 0.57, p = .011), and WWI (T1 = 10.72 ± 0.11 vs. T3 = 11.29 ± 0.09, p = .047) indices scores through the carbohydrate intake tertiles. Additionally, there was a significant increase in scores of AVI (T1 = 18.60 ± 0.56 vs. T3 = 21.42 ± 0.46, p = .048) and an almost significant increase in CI (T1 = 1.30 ± 0.01vs. T3 = 1.33 ± 0.01, p = .056) through the tertiles of protein intake.

CONCLUSION

Macronutrients were significantly associated with all indices. The effect of macronutrients on obesity indices is sex-based. Among men, CI, AVI, and WWI were the indices most affected by carbohydrate and protein intakes. Future studies should further investigate food sources and macronutrient quality.

Diet composition and energy intake in humans

Absolute energy from fats and carbohydrates and the proportion of carbohydrates in the food supply have increased over 50 years. Dietary energy density (ED) is primarily decreased by the water and increased by the fat content of foods. Protein, carbohydrates and fat exert different effects on satiety or energy intake (EI) in the order protein > carbohydrates > fat. When the ED of different foods is equalized the differences between fat and carbohydrates are modest. Covertly increasing dietary ED with fat, carbohydrate or mixed macronutrients elevates EI, producing weight gain and vice versa. In more naturalistic situations where learning cues are intact, there appears to be greater compensation for the different ED of foods. There is considerable individual variability in response. Macronutrient-specific negative feedback models of EI regulation have limited capacity to explain how availability of cheap, highly palatable, readily assimilated, energy-dense foods lead to obesity in modern environments. Neuropsychological constructs including food reward (liking, wanting and learning), reactive and reflective decision making, in the context of asymmetric energy balance regulation, give more comprehensive explanations of how environmental superabundance of foods containing mixtures of readily assimilated fats and carbohydrates and caloric beverages elevate EI through combined hedonic, affective, cognitive and physiological mechanisms. This article is part of a discussion meeting issue 'Causes of obesity: theories, conjectures and evidence (Part II)'.

Veganism and body weight: An N of 1 self-experiment

The causal effect that veganism has on body weight has not been scientifically examined. An N of 1 self-experiment was conducted in which blinded body weight and additional behavioural and psychological measures were assessed during two phases of vegan vs. non-vegan lifestyle adherence. In study phase 1, body weight change was -0.8 kg over 1 month of veganism (vs. +0.5 kg non-vegan month). In study phase 2, weight change was -1.2 kg over two veganism months (vs. +1.6 kg non-vegan months). Behavioural and psychological measures were similar during vegan vs. non-vegan periods. Veganism appeared to reduce body weight in this N of 1 self-experiment.

Effects of ketone bodies on energy expenditure, substrate utilization, and energy intake in humans

The potential of ketogenic approaches to regulate energy balance has recently gained attention since ketones may influence both energy expenditure and energy intake. In this narrative review, we summarized the most relevant evidence about the role of ketosis on energy expenditure, substrate utilization, and energy intake in humans. We considered different strategies to induce ketosis, such as fasting, dietary manipulation, and exogenous ketone sources. In general, ketosis does not have a major influence on energy expenditure but promotes a shift in substrate utilization towards ketone body oxidation. The strategies to induce ketosis by reduction of dietary carbohydrate availability (e.g., ketogenic diets) do not independently influence energy intake, being thus equally effective for weight loss as diets with higher carbohydrate content. In contrast, the intake of medium-chain triglycerides and ketone esters induces ketosis and appears to increase energy expenditure and reduce energy intake in the context of high carbohydrate availability. These latter strategies lead to slightly enhanced weight loss. Unfortunately, distinguishing the effects of the various ketogenic strategies per se from the effects of other physiological responses is not possible with the available human data. Highly controlled, inpatient studies using targeted strategies to isolate the independent effects of ketones are required to adequately address this knowledge gap.

Criterion validity of wrist accelerometry for assessing energy intake via the intake-balance technique

BACKGROUND

Intake-balance assessments measure energy intake (EI) by summing energy expenditure (EE) with concurrent change in energy storage (ΔES). Prior work has not examined the validity of such calculations when EE is estimated via open-source techniques for research-grade accelerometry devices. The purpose of this study was to test the criterion validity of accelerometry-based intake-balance methods for a wrist-worn ActiGraph device.

METHODS

Healthy adults (n = 24) completed two 14-day measurement periods while wearing an ActiGraph accelerometer on the non-dominant wrist. During each period, criterion values of EI were determined based on ΔES measured by dual X-ray absorptiometry and EE measured by doubly labeled water. A total of 11 prediction methods were tested, 8 derived from the accelerometer and 3 from non-accelerometry methods (e.g., diet recall; included for comparison). Group-level validity was assessed through mean bias, while individual-level validity was assessed through mean absolute error, mean absolute percentage error, and Bland-Altman analysis.

RESULTS

Mean bias for the three best accelerometry-based methods ranged from -167 to 124 kcal/day, versus -104 to 134 kcal/day for the non-accelerometry-based methods. The same three accelerometry-based methods had mean absolute error of 323-362 kcal/day and mean absolute percentage error of 18.1-19.3%, versus 353-464 kcal/day and 19.5-24.4% for the non-accelerometry-based methods. All 11 methods demonstrated systematic bias in the Bland-Altman analysis.

CONCLUSIONS

Accelerometry-based intake-balance methods have promise for advancing EI assessment, but ongoing refinement is necessary. We provide an R package to facilitate implementation and refinement of accelerometry-based methods in future research (see paulhibbing.com/IntakeBalance).

Metabolomic based approach to identify biomarkers of broccoli intake

It is well-established that consumption of cruciferous and brassica vegetables has a correlation with reduced rates of many negative health outcomes. There is an increased interest in identifying food intake biomarkers to address limitations related to self-reported dietary assessment. The study aims to identify biomarkers of broccoli intake using metabolomic approaches, examine the dose-response relationship, and predict the intake by multimarker panel. Eighteen volunteers consumed cooked broccoli in A-Diet Discovery study and fasting and postprandial urine samples were collected at 2, 4 and 24 hours. Subsequently the A-Diet Dose-response study was performed where volunteers consumed different portions of broccoli (49, 101 or 153 g) and urine samples were collected at the end of each intervention week. Urine samples were analysed by 1H-NMR and LC-MS. Multivariate data analysis and one-way ANOVA were performed to identify discriminating biomarkers. A panel of putative biomarkers was examined for its ability to predict intake through a multiMarker model. Multivariate analysis revealed discriminatory spectral regions between fasting and fed metabolic profiles. Subsequent time-series plots revealed multiple features increased in concentration following the consumption. Urinary S-methyl cysteine sulfoxide (SMCSO) increased as broccoli intake increased (0.17-0.24 μM per mOSM per kg, p < 0.001). Similarly from LC-MS data genipin, dihydro-β-tubaic acid and sinapic acid increased with increasing portions of intake. A panel of 8 features displayed good ability to predict intake from biomarker data only. In conclusion, urinary SMCSO and several LC-MS features appeared as potentially promising biomarkers of broccoli consumption and demonstrated dose-response relationship. Future work should focus on validating these compounds as food intake biomarkers.

The influence of physical activity on neural responses to visual food cues in humans: A systematic review of functional magnetic resonance imaging studies

This systematic review examined whether neural responses to visual food-cues measured by functional magnetic resonance imaging (fMRI) are influenced by physical activity. Seven databases were searched up to February 2023 for human studies evaluating visual food-cue reactivity using fMRI alongside an assessment of habitual physical activity or structured exercise exposure. Eight studies (1 exercise training, 4 acute crossover, 3 cross-sectional) were included in a qualitative synthesis. Structured acute and chronic exercise appear to lower food-cue reactivity in several brain regions, including the insula, hippocampus, orbitofrontal cortex (OFC), postcentral gyrus and putamen, particularly when viewing high-energy-density food cues. Exercise, at least acutely, may enhance appeal of low-energy-density food-cues. Cross-sectional studies show higher self-reported physical activity is associated with lower reactivity to food-cues particularly of high-energy-density in the insula, OFC, postcentral gyrus and precuneus. This review shows that physical activity may influence brain food-cue reactivity in motivational, emotional, and reward-related processing regions, possibly indicative of a hedonic appetite-suppressing effect. Conclusions should be drawn cautiously given considerable methodological variability exists across limited evidence.

Evaluating self-reported retrospective average daily fruit, vegetable, and egg intake: Trustworthy-Sometimes!

Retrospective self-reports are commonly used to assess dietary intake. Yet, their use is criticized as it is unclear whether the underlying assumptions for valid self-reports are met: Individuals have to consider the behavior of all days in the retention interval and weigh the behavior of all days equally. This study examines whether these assumptions for retrospective self-reports are met and whether interindividual differences in self-report performance are relevant regarding these assumptions. Ninety-two participants aged 18-61 years participated in seven sequential 24-h recalls and one retrospective 7-day recall concerning their intake of fruit, vegetables, and eggs. A multiple linear regression approach was used to examine the relation between the daily reported dietary intake and the 7-day recall. In the overall sample, the requirements for retrospective self-reports were not tenable. Distinguishing good and poor self-reporters based on a rational criterion showed that the requirements can be taken as given for good self-reporters, whereas poor self-reporters base their retrospective self-reports mostly on recency effects. The underlying requirements for retrospective self-reports appear to be met in two thirds of the sample, supporting the use of retrospective self-reports to capture dietary behavior. Future research should investigate characteristics separating good from poor self-reporters.

High- and normal-protein diets improve body composition and glucose control in adults with type 2 diabetes: a randomized trial

OBJECTIVE

Weight loss of ≥10% improves glucose control and may remit type 2 diabetes (T2D). High-protein (HP) diets are commonly used for weight loss, but whether protein sources, especially red meat, impact weight loss-induced T2D management is unknown. This trial compared an HP diet including beef and a normal-protein (NP) diet without red meat for weight loss, body composition changes, and glucose control in individuals with T2D.

METHODS

A total of 106 adults (80 female) with T2D consumed an HP (40% protein) diet with ≥4 weekly servings of lean beef or an NP (21% protein) diet excluding red meat during a 52-week weight loss intervention. Body weight, body composition, and cardiometabolic parameters were measured before and after intervention.

RESULTS

Weight loss was not different between the HP (-10.2 ± 1.6 kg) and NP (-12.7 ± 4.8 kg, p = 0.336) groups. Both groups reduced fat mass and increased fat-free mass percent. Hemoglobin A1c, glucose, insulin, insulin resistance, blood pressure, and triglycerides improved, with no differences between groups.

CONCLUSIONS

The lack of observed effects of dietary protein and red meat consumption on weight loss and improved cardiometabolic health suggests that achieved weight loss, rather than diet composition, should be the principal target of dietary interventions for T2D management.

Predicting energy intake with an accelerometer-based intake-balance method

Nutritional interventions often rely on subjective assessments of energy intake (EI), but these are susceptible to measurement error. To introduce an accelerometer-based intake-balance method for assessing EI using data from a time-restricted eating (TRE) trial. Nineteen participants with overweight/obesity (25-63 years old; 16 females) completed a 12-week intervention (NCT03129581) in a control group (unrestricted feeding; n 8) or TRE group (n 11). At the start and end of the intervention, body composition was assessed by dual-energy X-ray absorptiometry (DXA) and daily energy expenditure (EE) was assessed for 2 weeks via wrist-worn accelerometer. EI was back-calculated as the sum of net energy storage (from DXA) and EE (from accelerometer). Accelerometer-derived EI estimates were compared against estimates from the body weight planner of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Mean EI for the control group declined by 138 and 435 kJ/day for the accelerometer and NIDDK methods, respectively (both P ≥ 0·38), v. 1255 and 1469 kJ/day, respectively, for the TRE group (both P < 0·01). At follow-up, the accelerometer and NIDDK methods showed excellent group-level agreement (mean bias of -297 kJ/day across arms; standard error of estimate 1054 kJ/day) but high variability at the individual level (limits of agreement from -2414 to +1824 kJ/day). The accelerometer-based intake-balance method showed plausible sensitivity to change, and EI estimates were biologically and behaviourally plausible. The method may be a viable alternative to self-report EI measures. Future studies should assess criterion validity using doubly labelled water.

Habitual Physical Activity and Dietary Profiles in Older Japanese Males with Normal-Weight Obesity

Normal-weight obesity is defined as having high body fat but a normal body mass index (BMI). This study examined whether there are differences in habitual physical activity and diet between individuals with normal-weight obesity and obese or non-obesity. This study included 143 males aged 65-75 years, and they were classified into the following three groups according to BMI and visceral fat area (VFA): obese group (n = 27 (BMI: ≥25 kg/m² and VFA: ≥100 cm²)), normal-weight obese group (n = 35 (BMI: <25 kg/m² and VFA: ≥100 cm²)) and non-obese group (n = 81 (BMI: <25 kg/m² and VFA < 100 cm²)). Lowered high-density lipoprotein cholesterol and elevated triglyceride and alanine transaminase were observed in the normal-weight obese group than in the non-obese group (all for p ≤ 0.04, effect size ≥ 0.50). No differences were found in physical activity and dietary habits between non-obese and normal-weight obese groups (all for p > 0.05). Although impaired lipid and liver function parameters were observed in older males with normal-weight obesity compared with older males with non-obesity, physical activity and dietary profiles in themselves were not shown these differences in the present study.

Disentangling the effects of obesity and high-fat diet on glucose homeostasis using a photoperiod induced obesity model implicates ectopic fat deposition as a key factor

OBJECTIVE

Obesity in laboratory rodents is generally induced by feeding them a high fat diet (HFD). This model does not permit separation of the impact of the HFD from the resultant obesity on metabolic defects such as impaired glucose homeostasis. In Brandt's voles we have previously shown that exposure to long photoperiod (LD: 16L: 8D) induces obesity even when they are fed a low fat diet. We show here that these voles are largely resistant to HFD. This model therefore permits some separation of the effects of HFD and obesity on glucose homeostasis. The objective was therefore to use this model to assess if glucose homeostasis is more related to diet or obesity METHODS: Male voles, which were 35 days old and born in LD, were exposed to SD and a low fat diet for 70 days. We then randomly separated the animals into 4 groups for another 63 days: SL (short day and low fat diet: n = 19) group; SH (short day and high-fat diet, n = 20) group; LL (long day and low-fat diet, n = 20) group; LH (long day and high-fat diet, n = 18) group. Glucose tolerance tests (GTT) were performed after treatment for 56 days, and body compositions of the voles were quantified at the end by dissection.

RESULTS

Consistent with our previous work LD voles were more obese than SD voles. Although total body weight was independent of dietary fat content, HFD did have an effect on fat storage. Photoperiod induced obesity had no effect on glucose homeostasis, and the fat content in both the liver and muscle. In contrast, HFD induced adiposity was linked with elevated fat deposition in muscle (but not in liver) and led to impaired glucose tolerance.

CONCLUSIONS

The contrasting effects of diet and photoperiod were consistent with the predictions of the 'lipotoxicity hypothesis'. This may contribute to our understanding of why some human individuals are able to be obese yet remain metabolically healthy.

Equating NHANES Monitor-Based Physical Activity to Self-Reported Methods to Enhance Ongoing Surveillance Efforts

PURPOSE

Harmonization of assessment methods represents an ongoing challenge in physical activity research. Previous research has demonstrated the utility of calibration approaches to enhance agreement between measures of physical activity. The present study utilizes a calibration methodology to add behavioral context from the Global Physical Activity Questionnaire (GPAQ), an established report-based measure, to enhance interpretations of monitor-based data scored using the novel Monitor Independent Movement Summary (MIMS) methodology.

METHODS

Matching data from the GPAQ and MIMS were obtained from adults (20-80 yr of age) assessed in the 2011-2014 National Health and Nutrition Examination Survey. After developing percentile curves for self-reported activity, a zero-inflated quantile regression model was developed to link MIMS to estimates of moderate to vigorous physical activity (MVPA) from the GPAQ.

RESULTS

Cross-validation of the model showed that it closely approximated the probability of reporting MVPA across age and activity-level segments, supporting the accuracy of the zero-inflated model component. Validation of the quantile regression component directly corresponded to the 25%, 50%, and 75% values for both men and women, further supporting the model fit.

CONCLUSIONS

This study offers a method of improving activity surveillance by translating accelerometer signals into interpretable behavioral measures using nationally representative data. The model provides accurate estimates of minutes of MVPA at a population level but, because of the bias and error inherent in report-based measures of physical activity, is not suitable for converting or interpreting individual-level data. This study provides an important preliminary step in utilizing information from both device- and report-based methods to triangulate activity related outcomes; however additional measurement error modeling is needed to improve precision.