Exploring the acute effects of running on cerebral blood flow and food cue reactivity in healthy young men using functional magnetic resonance imaging.

Acute exercise suppresses appetite and alters food-cue reactivity, but the extent exercise-induced changes in cerebral blood flow (CBF) influences the blood-oxygen-level-dependent (BOLD) signal during appetite-related paradigms is not known. This study examined the impact of acute running on visual food-cue reactivity and explored whether such responses are influenced by CBF variability. In a randomised crossover design, 23 men (mean ± SD: 24 ± 4 years, 22.9 ± 2.1 kg/m2 ) completed fMRI scans before and after 60 min of running (68% ± 3% peak oxygen uptake) or rest (control). Five-minute pseudo-continuous arterial spin labelling fMRI scans were conducted for CBF assessment before and at four consecutive repeat acquisitions after exercise/rest. BOLD-fMRI was acquired during a food-cue reactivity task before and 28 min after exercise/rest. Food-cue reactivity analysis was performed with and without CBF adjustment. Subjective appetite ratings were assessed before, during and after exercise/rest. Exercise CBF was higher in grey matter, the posterior insula and in the region of the amygdala/hippocampus, and lower in the medial orbitofrontal cortex and dorsal striatum than control (main effect trial p ≤ .018). No time-by-trial interactions for CBF were identified (p ≥ .087). Exercise induced moderate-to-large reductions in subjective appetite ratings (Cohen's d = 0.53-0.84; p ≤ .024) and increased food-cue reactivity in the paracingulate gyrus, hippocampus, precuneous cortex, frontal pole and posterior cingulate gyrus. Accounting for CBF variability did not markedly alter detection of exercise-induced BOLD signal changes. Acute running evoked overall changes in CBF that were not time dependent and increased food-cue reactivity in regions implicated in attention, anticipation of reward, and episodic memory independent of CBF.

Associations of objectively measured physical activity, sedentary time and cardiorespiratory fitness with adipose tissue insulin resistance and ectopic fat.

BACKGROUND/OBJECTIVES: Inadequate movement, excess adiposity, and insulin resistance augment cardiometabolic risk. This study examined the associations of objectively measured moderate-to-vigorous intensity physical activity (MVPA), sedentary time and cardiorespiratory fitness (CRF), with adipose tissue insulin resistance and ectopic fat. METHODS: Data were combined from two previous experimental studies with community volunteers (n = 141, male = 60%, median (interquartile range) age = 37 (19) years, body mass index (BMI) = 26.1 (6.3) kg·m-2). Adipose tissue insulin resistance was assessed using the adipose tissue insulin resistance index (Adipo-IR); whilst magnetic resonance imaging (MRI) was used to measure liver, visceral (VAT) and subcutaneous abdominal adipose tissue (ScAT). Sedentary time and MVPA were measured via an ActiGraph GT3X+ accelerometer. Generalized linear models examined the association of CRF, MVPA, and sedentary time with Adipo-IR and fat depots. Interaction terms explored the moderating influence of age, sex, BMI and CRF. RESULTS: After controlling for BMI and cardiometabolic variables, sedentary time was positively associated with Adipo-IR (ß = 0.68 AU [95%CI = 0.27 to 1.10], P < 0.001). The association between sedentary time and Adipo-IR was moderated by age, CRF and BMI; such that it was stronger in individuals who were older, had lower CRF and had a higher BMI. Sedentary time was also positively associated with VAT (ß = 0.05 L [95%CI = 0.01 to 0.08], P = 0.005) with the relationship being stronger in females than males. CRF was inversely associated with VAT (ß = -0.02 L [95%CI = -0.04 to -0.01], P = 0.003) and ScAT (ß = -0.10 L [95%CI = -0.13 to -0.06], P < 0.001); with sex and BMI moderating the strength of associations with VAT and ScAT, respectively. CONCLUSIONS: Sedentary time is positively associated with adipose tissue insulin resistance which regulates lipogenesis and lipolysis. CRF is independently related to central fat storage which is a key risk factor for cardiometabolic disease.

The impact of acute exercise on appetite control: Current insights and future perspectives.

The interaction of exercise with appetite control and energy intake has been widely studied due to the ability of exercise-related energy expenditure to influence energy and substrate balance. Many empirical studies have explored appetite and energy intake responses to acute (single) exercise bouts involving a variety of protocols in diverse populations revealing several consistent trends. The balance of evidence suggests that acute moderate-to-vigorous intensity land-based exercise suppresses subjective appetite feelings and the orexigenic hormone acylated ghrelin and elevates the anorexigenic hormones peptide YY and glucagon-like peptide-1. These perturbations are transient and hormone concentrations usually return to resting values in the hours after exercise without evoking compensatory increases in appetite or energy intake on the same day. This evidence counters the popular assertion that exercise transiently increases appetite and may prompt greater energy intake at subsequent meals. The indifference of the appetite control system to acute exercise-induced energy deficits contrasts with the immediate increases in appetite and energy intake provoked by equivalent diet-induced energy deficits. There is, however, considerable inter-individual variability in subjective appetite and hormonal responses to acute exercise with some individuals experiencing greater exercise-induced appetite suppression than others. Current evidence supports the promotion of exercise as a strategy for inducing a short-term energy deficit but the relevance of this for long-term appetite regulation and the control of body mass remains uncertain.

Influence of water-based exercise on energy intake, appetite, and appetite-related hormones in adults: A systematic review and meta-analysis.

Single bouts of land-based exercise suppress appetite and do not typically alter energy intake in the short-term, whereas it has been suggested that water-based exercise may evoke orexigenic effects. The primary aim was to systematically review the available literature investigating the influence of water-based exercise on energy intake in adults (PROSPERO ID number CRD42022314349). PubMed, Medline, Sport-Discus, Academic Search Complete, CINAHL and Public Health Database were searched for peer-reviewed articles published in English from 1900 to May 2022. Included studies implemented a water-based exercise intervention versus a control or comparator. Risk of bias was assessed using the revised Cochrane 'Risk of bias tool for randomised trials' (RoB 2.0). We identified eight acute (same day) exercise studies which met the inclusion criteria. Meta-analysis was performed using a fixed effects generic inverse variance method on energy intake (8 studies (water versus control), 5 studies (water versus land) and 2 studies (water at two different temperatures)). Appetite and appetite-related hormones are also examined but high heterogeneity did not allow a meta-analysis of these outcome measures. We identified one chronic exercise training study which met the inclusion criteria with findings discussed narratively. Meta-analysis revealed that a single bout of exercise in water increased ad-libitum energy intake compared to a non-exercise control (mean difference [95% CI]: 330 [118, 542] kJ, P = 0.002). No difference in ad libitum energy intake was identified between water and land-based exercise (78 [-176, 334] kJ, P = 0.55). Exercising in cold water (18-20 °C) increased energy intake to a greater extent than neutral water (27-33 °C) temperature (719 [222, 1215] kJ; P < 0.005). The one eligible 12-week study did not assess whether water-based exercise influenced energy intake but did find that cycling and swimming did not alter fasting plasma concentrations of total ghrelin, insulin, leptin or total PYY but contributed to body mass loss 87.3 (5.2) to 85.9 (5.0) kg and 88.9 (4.9) to 86.4 (4.5) kg (P < 0.05) respectively. To conclude, if body mass management is a person's primary focus, they should be mindful of the tendency to eat more in the hours after a water-based exercise session, particularly when the water temperature is cold (18-20 °C).

Analytical Performance of the Factory-Calibrated Flash Glucose Monitoring System FreeStyle Libre2TM in Healthy Women.

Continuous glucose monitoring (CGM) is used clinically and for research purposes to capture glycaemic profiles. The accuracy of CGM among healthy populations has not been widely assessed. This study assessed agreement between glucose concentrations obtained from venous plasma and from CGM (FreeStyle Libre2TM, Abbott Diabetes Care, Witney, UK) in healthy women. Glucose concentrations were assessed after fasting and every 15 min after a standardized breakfast over a 4-h lab period. Accuracy of CGM was determined by Bland-Altman plot, 15/15% sensor agreement analysis, Clarke error grid analysis (EGA) and mean absolute relative difference (MARD). In all, 429 valid CGM readings with paired venous plasma glucose (VPG) values were obtained from 29 healthy women. Mean CGM readings were 1.14 mmol/L (95% CI: 0.97 to 1.30 mmol/L, p < 0.001) higher than VPG concentrations. Ratio 95% limits of agreement were from 0.68 to 2.20, and a proportional bias (slope: 0.22) was reported. Additionally, 45% of the CGM readings were within ±0.83 mmol/L (±15 mg/dL) or ±15% of VPG, while 85.3% were within EGA Zones A + B (clinically acceptable). MARD was 27.5% (95% CI: 20.8, 34.2%), with higher MARD values in the hypoglycaemia range and when VPG concentrations were falling. The FreeStyle Libre2TM CGM system tends to overestimate glucose concentrations compared to venous plasma samples in healthy women, especially during hypoglycaemia and during glycaemic swings.

Sleep extension and metabolic health in male overweight/obese short sleepers: A randomised controlled trial.

While limited evidence suggests that longer sleep durations can improve metabolic health in habitual short sleepers, there is no consensus on how sustained sleep extension can be achieved. A total of 18 men (mean [SD] age 41 [ 9] years), who were overweight/obese (mean [SD] body mass index 30 [3] kg/m2 ) and short sleepers at increased risk of type 2 diabetes were randomised to a 6-week sleep-extension programme based on cognitive behavioural principles (n = 10) or a control (n = 8) group. The primary outcome was 6-week change in actigraphic total sleep time (TST). Fasting plasma insulin, insulin resistance (Homeostatic Model Assessment for Insulin Resistance [HOMA-IR]), blood pressure, appetite-related hormones from a mixed-meal tolerance test, and continuous glucose levels were also measured. Baseline to 6-week change in TST was greater in the sleep-extension group, at 79 (95% confidence interval [CI] 68.90, 88.05) versus 6 (95% CI -4.43, 16.99) min. Change in the sleep-extension and control groups respectively also showed: lower fasting insulin (-11.03 [95% CI -22.70, 0.65] versus 7.07 [95% CI -4.60, 18.74] pmol/L); lower systolic (-11.09 [95% CI -17.49, -4.69] versus 0.76 [95% CI -5.64, 7.15] mmHg) and diastolic blood pressure (-12.16 [95% CI -17.74, -6.59] versus 1.38 [95% CI -4.19, 6.96] mmHg); lower mean amplitude of glucose excursions (0.34 [95% CI -0.57, -0.12] versus 0.05 [95% CI -0.20, 0.30] mmol/L); lower fasting peptide YY levels (-18.25 [95%CI -41.90, 5.41] versus 21.88 [95% CI -1.78, 45.53] pg/ml), and improved HOMA-IR (-0.51 [95% CI -0.98, -0.03] versus 0.28 [95% CI -0.20, 0.76]). Our protocol increased TST and improved markers of metabolic health in male overweight/obese short sleepers.

Higher levels of physical activity are associated with reduced tethering and migration of pro-inflammatory monocytes in males with central obesity.

Despite evidence that monocyte migration is accentuated by central adiposity, the impact of physical activity (PA) and exercise, particularly in the post-prandial state, on limiting migration are not established. We hypothesised that PA and a single bout of walking exercise would be associated with reduced ex vivo monocyte tethering and migration in middleaged males with central obesity (CO). Objective levels of PA were measured for 7 days in lean males (LE, N=12, mean (SD) age 39 (10) years, waist circumference 81.0 (6.3) cm) and males with CO (N=12, mean (SD) age 40 (9) years, waist circumference 115.3 (13.9) cm), followed by donation of a fasted blood sample. On the same day, CO undertook a bout of walking exercise, before donation of a second fasted blood sample. An ex vivo assay, coupled to flow cytometry, determined tethering and migration of classical, intermediate, and non-classical monocytes. C-C and CXC chemokine receptor (CCR2, CCR5 and CX3CR1) expression were also determined on total and classical monocytes. Monocyte subsets (total, classical, intermediate and CCR2+ monocytes), metabolic (glucose and lipids) and inflammatory (C-reactive protein) markers were greater in CO vs. LE (lower highdensity lipoprotein); however, adjustments for PA mitigated group differences for glucose, lipids, and monocyte subsets. Ex vivo tethering and migration (absolute and relative) of most monocyte subsets was greater in CO vs LE. Relative monocyte tethering and migration was largely not influenced by PA; however, higher PA was associated with reduced absolute migration and tethering of CD16 expressing monocytes in CO. Prior walking had no impact on these variables. These results highlight that regular PA, not single exercise bouts may limit the migration of pro-inflammatory monocytes in CO. These changes may relate to physiological parameters in blood (i.e. number of cells and their adhesion), rather than differences in chemokine receptor expression.

Effects of moderate to vigorous intensity cycling on appetite, ad libitum energy intake and appetite-related hormones in healthy South Asian and white European men.

Compensatory changes in appetite and energy intake do not appear to occur in the short-term after acute exercise; however, responses have not been compared in South Asians, a group at high risk of central obesity and type 2 diabetes, with white Europeans. This study examined appetite perceptions, energy intake and appetite-related hormones after moderate-to-vigorous intensity cycling in South Asian versus white European men. Fifteen South Asians (mean(SD) 29(8) years; 25.4(4.5) kg m-2) and fifteen white Europeans (33(10) years; 26.1(3.8) kg m-2) matched for age and body mass index completed two 7 h trials (control and exercise). Participants rested throughout both trials apart from completing 60 min cycling at 2-3 h in the exercise trial. A standardised breakfast was consumed at 0 h and an ad libitum buffet meal at 4 h. Appetite perceptions and appetite-related hormones were measured at predetermined intervals. Exercise suppressed acylated ghrelin (d = 0.19, P < 0.001) and increased total peptide YY (PYY) (d = 0.14, P = 0.004), insulin (d = 0.09, P = 0.046) and glucose concentrations (d = 0.31, P < 0.001) (main effect of trial), without stimulating compensatory increases in energy intakes in either group (group-by-trial interactions). South Asians exhibited lower absolute energy intake and higher insulin concentrations than white Europeans (main effect group d ≥ 0.63, P ≤ 0.003), whereas group-by-time interactions revealed lower acylated ghrelin concentrations at 3 and 4 h (d ≥ 0.75, P ≤ 0.038) and higher glucose concentrations at 0.75 and 2 h (d ≥ 0.67, P ≤ 0.008) in South Asian than white European men. These findings demonstrate that acute exercise induces a short-term energy deficit and similar appetite responses in South Asian and white European men.

Postprandial Metabolism and Physical Activity in Asians: A Narrative Review.

The widespread benefits of physical activity in enhancing health and lowering the risk of non-communicable chronic diseases are well established across populations globally. Nevertheless, the prevalence of several lifestyle-related chronic diseases, including cardiovascular disease, varies markedly across countries and ethnicities. Direct ethnic comparative studies on the health benefits of physical activity are sparse and evidence-based physical activity guidelines are not ethnicity-specific. Indeed, physical activity guidelines in some Asian countries were developed primarily based on data from Western populations even though the magnitude of potential benefit may not be the same among different ethnic groups. Unfavorable diurnal perturbations in postprandial triglycerides and glucose are risk factors for cardiovascular disease. This narrative review summarizes differences in these risk factors primarily between individuals of Asian and white European descent but also within different Asian groups. Moreover, the variable effects of physical activity on mitigating risk factors among these ethnic groups are highlighted along with the underlying metabolic and hormonal factors that potentially account for these differences. Future ethnic comparative studies should include investigations in understudied ethnic groups, such as those of East Asian origin, given that the effectiveness of physical activity for ameliorating cardiovascular disease varies even among Asian groups.

Acute Hyperenergetic, High-Fat Feeding Increases Circulating FGF21, LECT2, and Fetuin-A in Healthy Men.

BACKGROUND: Hepatokines such as fibroblast growth factor 21 (FGF21), leukocyte cell-derived chemotaxin 2 (LECT2), fetuin-A, fetuin-B, and selenoprotein P (SeP) are liver-derived proteins that are modulated by chronic energy status and metabolic disease. Emerging data from rodent and cell models indicate that hepatokines may be sensitive to acute nutritional manipulation; however, data in humans are lacking. OBJECTIVE: The aim was to investigate the influence of hyperenergetic, high-fat feeding on circulating hepatokine concentrations, including the time course of responses. METHODS: In a randomized, crossover design, 12 healthy men [mean ± SD: age, 24 ± 4 y; BMI (kg/m2), 24.1 ± 1.5] consumed a 7-d hyperenergetic, high-fat diet [HE-HFD; +50% energy, 65% total energy as fat (32% saturated, 26% monounsaturated, 8% polyunsaturated)] and control diet (36% total energy as fat), separated by 3 wk. Whole-body insulin sensitivity was assessed before and after each diet using oral-glucose-tolerance tests. Fasting plasma concentrations of FGF21 (primary outcome), LECT2, fetuin-A, fetuin-B, SeP, and related metabolites were measured after 1, 3, and 7 d of each diet. Hepatokine responses were analyzed using 2-factor repeated-measures ANOVA and subsequent pairwise comparisons. RESULTS: Compared with the control, the HE-HFD increased circulating FGF21 at 1 d (105%) and 3 d (121%; P ≤ 0.040), LECT2 at 3 d (17%) and 7 d (32%; P ≤ 0.004), and fetuin-A at 7 d (7%; P = 0.028). Plasma fetuin-B and SeP did not respond to the HE-HFD. Whole-body insulin sensitivity was reduced after the HE-HFD by 31% (P = 0.021). CONCLUSIONS: Acute high-fat overfeeding augments circulating concentrations of FGF21, LECT2, and fetuin-A in healthy men. Notably, the time course of response varies between proteins and is transient for FGF21. These findings provide further insight into the nutritional regulation of hepatokines in humans and their interaction with metabolic homeostasis. This study was registered at clinicaltrials.gov as NCT03369145.

Correction to: Energy replacement diminishes the postprandial triglyceride­lowering effect from accumulated walking in older women.

The original version of this article unfortunately contained a mistake. The error of NEFA AUC values in first (mean and 95% CI) and the main text (effect size and 95% CI).

Energy replacement diminishes the postprandial triglyceride-lowering effect from accumulated walking in older women.

PURPOSE: Dietary replacement of an acute exercise-induced energy deficit offsets the postprandial triglyceride (TG)-lowering effect of exercise in young boys and middle-aged men. It is unclear whether these findings are observed when exercise is accumulated in older adults. This study examined the effect of accumulating short bouts of exercise, with and without dietary replacement of an exercise-induced energy deficit, on postprandial TG in older women. METHODS: Seventeen older women (≥ 65 years) underwent three, 8-h trials: (1) control, (2) accumulated walking and (3) accumulated walking with energy replacement. During the control trial, participants rested for 8 h. The accumulated walking trials comprised twenty 1.5 min brisk walking bouts performed at a pre-determined self-selected pace separated by 15 min seated rest. In each trial, participants consumed a standardised breakfast and lunch. The breakfast in the accumulated walking with energy replacement trial included replacement of the energy deficit (0.62 MJ, 149 kcal) induced by exercise. Venous blood samples were collected fasted and at 2, 4, 6 and 8 h after breakfast. RESULTS: Time-averaged postprandial serum TG concentrations over 8 h were lower after accumulated walking than control and accumulated walking with energy replacement (mean ± SD: 1.46 ± 0.93 vs 1.71 ± 1.01 vs 1.60 ± 0.98 mmol/L, respectively: main effect of trial p = 0.017). There was little difference between control and accumulated walking with energy replacement. CONCLUSIONS: Replacing the energy expenditure induced by accumulating 30 min of brisk walking in short (1.5 min) bouts diminishes the postprandial TG-lowering effect in older women.

An acute bout of swimming increases post-exercise energy intake in young healthy men and women.

Single bouts of land-based exercise (for example, walking, running, cycling) do not typically alter post-exercise energy intake on the day of exercise. However, anecdotal and preliminary empirical evidence suggests that swimming may increase appetite and energy intake. This study compared the acute effects of swimming on appetite, energy intake, and food preference and reward, versus exertion-matched cycling and a resting control. Thirty-two men (n = 17; mean ± SD age 24 ± 2 years, body mass index [BMI] 25.0 ± 2.6 kg/m2) and women (n = 15; age 22 ± 3 years, BMI 22.8 ± 2.3 kg/m2) completed three experimental trials (swimming, cycling, control) in a randomised, crossover design. The exercise trials involved 60-min of 'hard' exercise (self-selected rating of perceived exertion: 15) performed 90-min after a standardised breakfast. Food preference and reward were assessed via the Leeds Food Preference Questionnaire 15-min after exercise, whilst ad libitum energy intake was determined 30-min after exercise. The control trial involved identical procedures except no exercise was performed. Compared with control (3259 ± 1265 kJ), swimming increased ad libitum energy intake (3857 ± 1611 kJ; ES = 0.47, 95% CI of the mean difference between trials 185, 1010 kJ, P = 0.005); the magnitude of increase was smaller after cycling (3652 ± 1619 kJ; ES = 0.31, 95% CI -21, 805 kJ, P = 0.062). Ad libitum energy intake was similar between swimming and cycling (ES = 0.16, 95% CI -207, 618 kJ, P = 0.324). This effect was consistent across sexes and unrelated to food preference and reward which were similar after swimming and cycling compared with control. This study has identified an orexigenic effect of swimming. Further research is needed to identify the responsible mechanism(s), including the relevance of water immersion and water temperature per se.

True Interindividual Variability Exists in Postprandial Appetite Responses in Healthy Men But Is Not Moderated by the FTO Genotype.

BACKGROUND: After meal ingestion, a series of coordinated hormone responses occur concomitantly with changes in perceived appetite. It is not known whether interindividual variability in appetite exists in response to a meal. OBJECTIVES: The aim of this study was to 1) assess the reproducibility of appetite responses to a meal; 2) quantify individual differences in responses; and 3) explore any moderating influence of the fat mass and obesity associated (FTO) gene. METHODS: Using a replicated crossover design, 18 healthy men (mean ± SD age: 28.5 ± 9.8 y; BMI: 27.0 ± 5.0 kg/m2) recruited according to FTO genotype (9 AA, 9 TT) completed 2 identical control and 2 identical standardized meal conditions (5025 kJ) in randomized sequences. Perceived appetite and plasma acylated ghrelin, total peptide YY (PYY), insulin, and glucose concentrations were measured before and after interventions as primary outcomes. Interindividual differences were explored using Pearson's product-moment correlations between the first and second replicates of the control-adjusted meal response. Within-participant covariate-adjusted linear mixed models were used to quantify participant-by-condition and genotype-by-condition interactions. RESULTS: The meal suppressed acylated ghrelin and appetite perceptions [standardized effect size (ES): 0.18-4.26] and elevated total PYY, insulin, and glucose (ES: 1.96-21.60). For all variables, SD of change scores was greater in the meal than in the control conditions. Moderate-to-large positive correlations were observed between the 2 replicates of control-adjusted meal responses for all variables (r = 0.44-0.86, P ≤ 0.070). Participant-by-condition interactions were present for all variables (P ≤ 0.056). FTO genotype-by-condition interactions were nonsignificant (P ≥ 0.19) and treatment effect differences between genotype groups were small (ES ≤ 0.27) for all appetite parameters. CONCLUSIONS: Reproducibility of postprandial appetite responses is generally good. True interindividual variability is present beyond any random within-subject variation in healthy men but we detected no moderation by the FTO genotype. These findings highlight the importance of exploring individual differences in appetite for the prevention and treatment of obesity. This trial was registered at clinicaltrials.gov as NCT03771690.

Exploration of associations between the FTO rs9939609 genotype, fasting and postprandial appetite-related hormones and perceived appetite in healthy men and women.

BACKGROUND: The fat mass and obesity-associated gene (FTO) rs9939609 A-allele has been associated with obesity risk. Although the exact mechanisms involved remain unknown, the FTO rs9939609 A-allele has been associated with an impaired postprandial suppression of appetite. OBJECTIVES: To explore the influence of FTO rs9939609 genotype on fasting and postprandial appetite-related hormones and perceived appetite in a heterogeneous sample of men and women. DESIGN: 112 healthy men and women aged 18-50-years-old completed three laboratory visits for the assessment of FTO rs9939609 genotype, body composition, aerobic fitness, resting metabolic rate, visceral adipose tissue, liver fat, fasting leptin, and fasting and postprandial acylated ghrelin, total PYY, insulin, glucose and perceived appetite. Participants wore accelerometers for seven consecutive days for the assessment of physical activity and sedentary behaviour. Multivariable general linear models quantified differences between FTO rs9939609 groups for fasting and postprandial appetite outcomes, with and without the addition of a priori selected physiological and behavioural covariates. Sex-specific univariable Pearson's correlation coefficients were quantified between the appetite-related outcomes and individual characteristics. RESULTS: 95% confidence intervals for mean differences between FTO rs9939609 groups overlapped zero in unadjusted and adjusted general linear models for all fasting (P ≥ 0.28) and postprandial (P ≥ 0.19) appetite-related outcomes. Eta2 values for explained variance attributable to FTO rs9939609 were <5% for all outcomes. An exploratory correlation matrix indicated that associations between fasting and postprandial acylated ghrelin, total PYY and general or abdominal adiposity were also small (r = -0.23 to 0.15, P ≥ 0.09). Fasting leptin, glucose and insulin and postprandial insulin concentrations were associated with adiposity outcomes (r = 0.29 to 0.81, P ≤ 0.033). CONCLUSIONS: Associations between the FTO rs9939609 genotype and fasting or postprandial appetite-related outcomes were weak in healthy men and women.

Sex differences in postprandial lipaemia after acute high-intensity interval running in young people.

Acute exercise reduces postprandial triacylglycerol concentrations ([TAG]) in boys and girls; however, it is not known whether between-sex differences exist in response to exercise. Fifteen boys (mean(SD): 11.8(0.4) years) and sixteen girls (12.1(0.7) years) completed two, 2-day conditions. On day 1, participants rested (CON) or completed 10 × 1 min high-intensity interval runs at 100% maximal aerobic speed with 1 min recovery (HIIR). On day 2, participants consumed a standardised breakfast and lunch over a 6.5-h period during which seven capillary blood samples were collected. Based on ratios of the geometric means (95% CI for ratios), fasting [TAG] was 32% lower in boys than girls (-44 to -18%, ES = 1.31, P < 0.001), and 12% lower after HIIR than CON (-18 to -5%, ES = 0.42, P = 0.003); the magnitude of reduction was not significantly different between the sexes (8% (ES = 0.36) vs. 15% (ES = 0.47), respectively; P = 0.29). The total area under the [TAG] versus time curve was 27% lower in boys than girls (-40 to -10%, ES = 1.02, P = 0.005), and 10% lower after HIIR than CON (-16 to -5%, ES = 0.36, P = 0.001); the magnitude of reduction was similar between the sexes (11% (ES = 0.43) vs. 10% (ES = 0.31), respectively; P = 0.87). The small-moderate reduction in postprandial [TAG] after HIIR was similar between the sexes.

Acute high-intensity interval rowing increases thrombin generation in healthy men.

PURPOSE: High-intensity exercise induces several health benefits, but may acutely and transiently increase the risk of cardiovascular events due to thrombotic changes promoting blood coagulation and thrombin formation. This study examined the effects of high-intensity exercise on plasma thrombin generation and triacylglycerol concentrations. METHODS: Sixteen healthy men completed two, 2-day conditions separated by 1 week. On day 1, participants rested (control) or completed four, 3-min high-intensity rowing intervals at an average rating of perceived exertion of 17 (exercise). Venous blood samples were collected pre- and post-intervention to determine plasma thrombin generation. On day 2, participants rested and consumed a glucose load (0 h) and high-fat meal (2 h). Fifteen venous blood samples were collected between 0 and 8 h to measure plasma thrombin generation and triacylglycerol concentrations. RESULTS: On day 1, lag time was shorter and peak thrombin and endogenous thrombin potential were greater in the exercise than control condition (ES ≥ 0.37, main effect condition P ≤ 0.03), and post-intervention compared with pre-intervention (ES ≥ 0.49, main effect time P ≤ 0.003). The magnitude of the post-intervention change was greater in the exercise than control condition for all thrombin generation parameters (condition by time interaction P ≤ 0.05). On day 2, no differences in postprandial thrombin generation parameters were seen between conditions (P ≥ 0.21). The total area under the curve for triacylglycerol was lower in the exercise than control condition (ES = 0.34, P = 0.02). CONCLUSION: An acute bout of high-intensity interval rowing increased plasma thrombin generation immediately after exercise, but these differences were eliminated 16-24 h after exercise.

The effect of prior walking on coronary heart disease risk markers in South Asian and European men.

PURPOSE: Heart disease risk is elevated in South Asians possibly due to impaired postprandial metabolism. Running has been shown to induce greater reductions in postprandial lipaemia in South Asian than European men, but the effect of walking in South Asians is unknown. METHODS: Fifteen South Asian and 14 white European men aged 19-30 years completed two, 2-day trials in a randomised crossover design. On day 1, participants rested (control) or walked for 60 min at approximately 50 % maximum oxygen uptake (exercise). On day 2, participants rested and consumed two high-fat meals over a 9-h period during which 14 venous blood samples were collected. RESULTS: South Asians exhibited higher postprandial triacylglycerol [geometric mean (95 % confidence interval) 2.29 (1.82 to 2.89) vs. 1.54 (1.21 to 1.96) mmol L(-1) h(-1)], glucose [5.49 (5.21 to 5.79) vs. 5.05 (4.78 to 5.33) mmol L(-1) h(-1)], insulin [32.9 (25.7 to 42.1) vs. 18.3 (14.2 to 23.7) µU mL(-1) h(-1)] and interleukin-6 [2.44 (1.61 to 3.67) vs. 1.04 (0.68 to 1.59) pg mL(-1) h(-1)] than Europeans (all ES ≥ 0.72, P ≤ 0.03). Between-group differences in triacylglycerol, glucose and insulin were not significant after controlling for age and percentage body fat. Walking reduced postprandial triacylglycerol [1.79 (1.52 to 2.12) vs. 1.97 (1.67 to 2.33) mmol L(-1) h(-1)] and insulin [21.0 (17.0 to 26.0) vs. 28.7 (23.2 to 35.4) µU mL(-1) h(-1)] (all ES ≥ 0.23. P ≤ 0.01), but group differences were not significant. CONCLUSIONS: Healthy South Asians exhibited impaired postprandial metabolism compared with white Europeans, but these differences were diminished after controlling for potential confounders. The small-moderate reduction in postprandial triacylglycerol and insulin after brisk walking was not different between the ethnicities.

Are There Interindividual Responses of Cardiovascular Disease Risk Markers to Acute Exercise? A Replicate Crossover Trial.

PURPOSE: Using a replicated crossover design, we quantified the response heterogeneity of postprandial cardiovascular disease risk marker responses to acute exercise. METHODS: Twenty men (mean (SD) age, 26 (6) yr; body mass index, 23.9 (2.4) kg·m -2 ) completed four 2-d conditions (two control, two exercise) in randomized orders. On days 1 and 2, participants rested and consumed two high-fat meals over 9 h. Participants ran for 60 min (61 (7)% of peak oxygen uptake) on day 1 (6.5 to 7.5 h) of both exercise conditions. Time-averaged total area under the curve (TAUC) for triacylglycerol, glucose, and insulin were calculated from 11 venous blood samples on day 2. Arterial stiffness and blood pressure responses were calculated from measurements at baseline on day 1 and at 2.5 h on day 2. Consistency of individual differences was explored by correlating the two replicates of control-adjusted exercise responses for each outcome. Within-participant covariate-adjusted linear mixed models quantified participant-by-condition interactions and individual response SDs. RESULTS: Acute exercise reduced mean TAUC-triacylglycerol (-0.27 mmol·L -1 ·h; Cohen's d = 0.29, P = 0.017) and TAUC-insulin (-25 pmol·L -1 ·h; Cohen's d = 0.35, P = 0.022) versus control, but led to negligible changes in TAUC-glucose and the vascular outcomes (Cohen's d ≤ 0.36, P ≥ 0.106). Small-to-moderate, but nonsignificant, correlations were observed between the two response replicates ( r = -0.42 to 0.15, P ≥ 0.066). We did not detect any individual response heterogeneity. All participant-by-condition interactions were P ≥ 0.137, and all individual response SDs were small with wide 95% confidence intervals overlapping zero. CONCLUSIONS: Large trial-to-trial within-subject variability inhibited detection of consistent interindividual variability in postprandial metabolic and vascular responses to acute exercise.

The association of smoking with different eating and dietary behaviours: A cross-sectional analysis of 80 296 United Kingdom adults.

BACKGROUND AND AIMS: Smokers typically have a lower body mass index (BMI) than non-smokers, while smoking cessation is associated with weight gain. In pre-clinical research, nicotine in tobacco smoking suppresses appetite and influences subsequent eating behaviour; however, this relationship is unclear in humans. This study measured the associations of smoking with different eating and dietary behaviours. DESIGN: A cross-sectional analysis of data from health assessments conducted between 2004 and 2022. SETTING: An independent healthcare-based charity within the United Kingdom. PARTICIPANTS: A total of 80 296 men and women (mean ± standard deviation [SD]: age, 43.0 ± 10.4 years; BMI, 25.7 ± 4.2 kg/m2; 62.5% male) stratified into two groups based on their status as a smoker (n = 6042; 7.5%) or non-smoker (n = 74 254; 92.5%). MEASUREMENTS: Smoking status (self-report) was the main exposure, while the primary outcomes were selected eating and dietary behaviours. Age, sex and socioeconomic status (index of multiple deprivation [IMD]) were included as covariates and interaction terms, while moderate-to-vigorous exercise and sleep quality were included as covariates only. FINDINGS: Smokers had lower odds of snacking between meals and eating food as a reward or out of boredom versus non-smokers (all odds ratio [OR] ≤ 0.82; P < 0.001). Furthermore, smokers had higher odds of skipping meals, going more than 3 h without food, adding salt and sugar to their food, overeating and finding it hard to leave something on their plate versus non-smokers (all OR ≥ 1.06; P ≤ 0.030). Additionally, compared with non-smokers, smoking was associated with eating fried food more times per week (rate ratio [RR] = 1.08; P < 0.001), eating fewer meals per day, eating sweet foods between meals and eating dessert on fewer days per week (all RR ≤ 0.93; P < 0.001). Several of these relationships were modified by age, sex and IMD. CONCLUSIONS: Smoking appears to be associated with eating and dietary behaviours consistent with inhibited food intake, low diet quality and altered food preference. Several of these relationships are moderated by age, sex and socioeconomic status.