Deconstructing interindividual variability in energy metabolism: implications for metabolic health.

A person's metabolic rate corresponds to the whole body level sum of all oxidative reactions occurring on the cellular level. The energy expenditure (EE) can be categorized into various obligatory and facultative processes. In sedentary adults, basal metabolic rate is the largest contributor to total daily EE, and interindividual variability can be significant. Additional EE is required for digesting and metabolizing food, thermoregulatory adaptation to cold, and to support exercise and nonexercise body movements. Interindividual variability also exists for these EE processes, even after controlling for known factors. The complex mechanisms of interindividual variability in EE can have genetic and environmental origins and require further investigation. Exploration of interindividual variability in EE and its underlying factors holds importance to metabolic health, as it may predict disease risk, and be useful in the personalization of preventative and treatment strategies.

The role of postprandial thermogenesis in the development of impaired glucose tolerance and type II diabetes.

Accounting for 5%-15% of total daily energy expenditure, postprandial thermogenesis (PPT) refers to an acute increase in resting metabolic rate (RMR) in the hours after eating. This is largely explained by the energy costs of processing the macronutrients of a meal. Most individuals spend the majority of the day in the postprandial state, thus over one's lifetime even minor differences in PPT may possess true clinical significance. In contrast to RMR, research indicates that PPT may be reduced in the development of both prediabetes and type II diabetes (T2D). The present analysis of existing literature has found that this impairment may be exaggerated in hyperinsulinemic-euglycemic clamp studies compared with food and beverage consumption studies. Nonetheless, it is estimated that daily PPT following carbohydrate consumption alone is approximately 150 kJ lower among individuals with T2D. This estimate fails to consider protein intake, which is notably more thermogenic than carbohydrate intake (20%-30% vs. 5%-8%, respectively). Putatively, dysglycemic individuals may lack the insulin sensitivity required to divert glucose toward storage-a more energy-taxing pathway. Accordingly, the majority of findings has associated an impaired PPT with a reduced "obligatory" energy output (i.e., the energy costs associated with nutrient processing). More recently, it has been reported that "facultative" thermogenesis [e.g., the energy costs associated with sympathetic nervous system (SNS) stimulation] may also contribute to any impairment in PPT among individuals with prediabetes and T2D. Further longitudinal research is required to truly ascertain whether meaningful changes in PPT manifest in the prediabetic state, before the development of T2D.

Low 24-hour core body temperature as a thrifty metabolic trait driving catch-up fat during weight regain after caloric restriction.

The recovery of body weight after substantial weight loss or growth retardation is often characterized by a disproportionately higher rate of fat mass vs. lean mass recovery, with this phenomenon of "preferential catch-up fat" being contributed by energy conservation (thrifty) metabolism. To test the hypothesis that a low core body temperature (Tc) constitutes a thrifty metabolic trait underlying the high metabolic efficiency driving catch-up fat, the Anipill system, with telemetry capsules implanted in the peritoneal cavity, was used for continuous monitoring of Tc for several weeks in a validated rat model of semistarvation-refeeding in which catch-up fat is driven solely by suppressed thermogenesis. In animals housed at 22°C, 24-h Tc was reduced in response to semistarvation (-0.77°C, P < 0.001) and remained significantly lower than in control animals during the catch-up fat phase of refeeding (-0.27°C on average, P < 0.001), the lower Tc during refeeding being more pronounced during the light phase than during the dark phase of the 24-h cycle (-0.30°C vs. -0.23°C, P < 0.01) and with no between-group differences in locomotor activity. A lower 24-h Tc in animals showing catch-up fat was also observed when the housing temperature was raised to 29°C (i.e., at thermoneutrality). The reduced energy cost of homeothermy in response to caloric restriction persists during weight recovery and constitutes a thrifty metabolic trait that contributes to the high metabolic efficiency that underlies the rapid restoration of the body's fat stores during weight regain, with implications for obesity relapse after therapeutic slimming and the pathophysiology of catch-up growth.

Standing economy: does the heterogeneity in the energy cost of posture maintenance reside in differential patterns of spontaneous weight-shifting?

PURPOSE: Due to sedentarity-associated disease risks, there is much interest in methods to increase low-intensity physical activity. In this context, it is widely assumed that altering posture allocation can modify energy expenditure (EE) to impact body-weight regulation and health. However, we have recently shown the existence of two distinct phenotypes pertaining to the energy cost of standing-with most individuals having no sustained increase in EE during steady-state standing relative to sitting comfortably. Here, we investigated whether these distinct phenotypes are related to the presence/absence of spontaneous "weight-shifting", i.e. the redistribution of body-weight from one foot to the other. METHODS: Using indirect calorimetry to measure EE in young adults during sitting and 10 min of steady-state standing, we examined: (i) heterogeneity in EE during standing (n = 36); (ii) EE and spontaneous weight-shifting patterns (n = 18); (iii) EE during spontaneous weight-shifting versus experimentally induced weight-shifting (n = 7), and; (iv) EE during spontaneous weight-shifting versus intermittent leg/body displacement (n = 6). RESULTS: Despite heterogeneity in EE response to steady-state standing, no differences were found in the amount or pattern of spontaneous weight-shifting between the two phenotypes. Whilst experimentally induced weight-shifting resulted in a mean EE increase of only 11% (range: 0-25%), intermittent leg/body displacement increased EE to >1.5 METs in all participants. CONCLUSIONS: Although the variability in spontaneous weight-shifting signatures between individuals does not appear to underlie heterogeneity in the energy cost of standing posture maintenance, these studies underscore the fact that leg/body displacement, rather than standing posture alone, is needed to increase EE above the currently defined sedentary threshold.

Oral non-steroidal anti-inflammatory drugs versus other oral analgesic agents for acute soft tissue injury.

BACKGROUND: Acute soft tissue injuries are common and costly. The best drug treatment for such injuries is not certain, although non-steroidal anti-inflammatory drugs (NSAIDs) are often recommended. OBJECTIVES: To assess the effects (benefits and harms) of NSAIDs compared with other oral analgesics for treating acute soft tissue injuries. SEARCH METHODS: We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (12 September 2014), the Cochrane Central Register of Controlled Trials (The Cochrane Library, 2014 Issue 8), MEDLINE (1966 to September 2014), EMBASE (1980 to September 2014), CINAHL (1937 to November 2012), AMED (1985 to November 2012), International Pharmaceutical Abstracts (1970 to November 2012), PEDro (1929 to November 2012), and SPORTDiscus (1985 to November 2012), plus internet search engines, trial registries and other databases. We also searched reference lists of relevant articles and contacted authors of retrieved studies and pharmaceutical companies to obtain relevant unpublished data. SELECTION CRITERIA: We included randomised or quasi-randomised controlled trials involving people with acute soft tissue injury (sprain, strain or contusion of a joint, ligament, tendon or muscle occurring up to 48 hours prior to inclusion in the study) and comparing oral NSAID versus paracetamol (acetaminophen), opioid, paracetamol plus opioid, or complementary and alternative medicine. The outcomes were pain, swelling, function, adverse effects and early re-injury. DATA COLLECTION AND ANALYSIS: At least two review authors independently assessed studies for eligibility, extracted data and assessed risk of bias. We assessed the quality of the evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology. MAIN RESULTS: We included 16 trials, with a total of 2144 participants. Two studies included children only. The other 14 studies included predominantly young adults, of whom over 60% were male. Seven studies recruited people with ankle sprains only. Most studies were at low or unclear risk of bias; however, two were at high risk of selection bias, three were at high risk of bias from lack of blinding, one was at high risk of bias due to incomplete outcome data, and four were at high risk of selective outcome reporting bias. The evidence was usually either low quality or very low quality, reflecting study limitations, indirectness such from as suboptimal dosing of single comparators, imprecision, or one or more of these. Thus we are either uncertain or very uncertain of the estimates.Nine studies, involving 991 participants, compared NSAIDs with paracetamol. While tending to favour paracetamol, there was a lack of clinically important differences between the two groups in pain at less than 24 hours (377 participants, 4 studies; moderate-quality evidence), at days 1 to 3 (431 participants, 4 studies; low quality), and at day 7 or over (467 participants, 4 studies; low quality). A similar lack of difference between the two groups applied to swelling at day 3 (86 participants, 1 study; very low quality) and at day 7 or over (77 participants, 1 study; low quality). There was little difference between the two groups in return to function at day 7 or over (316 participants, 3 studies; very low quality): based on an assumed recovery of function of 804 per 1000 participants in the paracetamol group, 8 fewer per 1000 recovered in the NSAID group (95% confidence interval (CI) 80 fewer to 73 more). There was low-quality evidence of a lower risk of gastrointestinal adverse events in the paracetamol group: based on an assumed risk of gastrointestinal adverse events of 16 per 1000 participants in the paracetamol group, 13 more participants per 1000 had a gastrointestinal adverse event in the NSAID group (95% CI 0 to 35 more).Four studies, involving 958 participants, compared NSAIDs with opioids. Since a study of a selective COX-2 inhibitor NSAID (valdecoxib) that was subsequently withdrawn from the market dominates the evidence for this comparison (706 participants included in the analyses for pain, function and gastrointestinal adverse events), the applicability of these results is in doubt and we give only a brief summary. There was low quality evidence for a lack of clinically important differences between the two groups regarding pain at less than 24 hours, at days 4 to 6, and at day 7. Evidence from single studies showed a similar lack of difference between the two groups for swelling at day 3 (68 participants) and day 10 (84 participants). Return to function at day 7 or over favoured the NSAID group (low-quality), and there were fewer gastrointestinal adverse events in the selective COX-2 inhibitor NSAID group (very low quality).Four studies, involving 240 participants, compared NSAIDs with the combination of paracetamol and an opioid. The applicability of findings from these studies is partly in question because the dextropropoxyphene combination analgesic agents used are no longer in general use. While the point estimates favoured NSAID, the very low-quality evidence did not show a difference between the two interventions in the numbers with little or no pain at day 1 (51 participants, 1 study), day 3 (149 participants, 2 studies), or day 7 (138 participants, 2 studies). Very low-quality evidence showed a similar lack of difference between the two groups applied to swelling at day 3 (reported in two studies) and at day 7 (reported in two studies), in return to function at day 7 (89 participants, 1 study), and in gastrointestinal adverse events (141 participants, 3 studies).No studies compared NSAIDs with complementary and alternative medicines, and no study reported re-injury rates. AUTHORS' CONCLUSIONS: There is generally low- or very low-quality but consistent evidence of no clinically important difference in analgesic efficacy between NSAIDs and other oral analgesics. There is low-quality evidence of more gastrointestinal adverse effects with non-selective NSAID compared with paracetamol. There is low- or very low-quality evidence of better function and fewer adverse events with NSAIDs compared with opioid-containing analgesics; however, one study dominated this evidence using a now unavailable COX-2 selective NSAID and is of uncertain applicability. Further research is required to determine whether there is any difference in return to function or adverse effects between both non-selective and COX-2 selective NSAIDs versus paracetamol.

Human Metabolism and Excretion of Kawakawa (Piper excelsum) Leaf Chemicals.

SCOPE: Piper excelsum (kawakawa) has a history of therapeutic use by Maori in Aotearoa New Zealand. It is currently widely consumed as a beverage and included as an ingredient in "functional" food product. Leaves contain compounds that are also found in a wide range of other spices, foods, and medicinal plants. This study investigates the human metabolism and excretion of kawakawa leaf chemicals. METHODS AND RESULTS: Six healthy male volunteers in one study (Bioavailability of Kawakawa Tea metabolites in human volunteers [BOKA-T]) and 30 volunteers (15 male and 15 female) in a second study (Impact of acute Kawakawa Tea ingestion on postprandial glucose metabolism in healthy human volunteers [TOAST]) consume a hot water infusion of dried kawakawa leaves (kawakawa tea [KT]). Untargeted Liquid Chromatography-Tandem Mass spectrometry (LC-MS/MS) analyses of urine samples from BOKA-T identified 26 urinary metabolites that are significantly associated with KT consumption, confirmed by the analysis of samples from the independent TOAST study. Seven of the 26 metabolites are also detected in plasma. Thirteen of the 26 urinary compounds are provisionally identified as metabolites of specific compounds in KT, eight metabolites are identified as being derived from specific compounds in KT but without resolution of chemical structure, and five are of unknown origin. CONCLUSIONS: Several kawakawa compounds that are also widely found in other plants are bioavailable and are modified by phase 1 and 2 metabolism.

Utilising a Clinical Metabolomics LC-MS Study to Determine the Integrity of Biological Samples for Statistical Modelling after Long Term -80 °C Storage: A TOFI_Asia Sub-Study.

Biological samples of lipids and metabolites degrade after extensive years in -80 °C storage. We aimed to determine if associated multivariate models are also impacted. Prior TOFI_Asia metabolomics studies from our laboratory established multivariate models of metabolic risks associated with ethnic diversity. Therefore, to compare multivariate modelling degradation after years of -80 °C storage, we selected a subset of aged (≥5-years) plasma samples from the TOFI_Asia study to re-analyze via untargeted LC-MS metabolomics. Samples from European Caucasian (n = 28) and Asian Chinese (n = 28) participants were evaluated for ethnic discrimination by partial least squares discriminative analysis (PLS-DA) of lipids and polar metabolites. Both showed a strong discernment between participants ethnicity by features, before (Initial) and after (Aged) 5-years of -80 °C storage. With receiver operator characteristic curves, sparse PLS-DA derived confusion matrix and prediction error rates, a considerable reduction in model integrity was apparent with the Aged polar metabolite model relative to Initial modelling. Ethnicity modelling with lipids maintained predictive integrity in Aged plasma samples, while equivalent polar metabolite models reduced in integrity. Our results indicate that researchers re-evaluating samples for multivariate modelling should consider time at -80 °C when producing predictive metrics from polar metabolites, more so than lipids.

Intra-pancreatic fat is associated with high circulating glucagon and GLP-1 concentrations following whey protein ingestion in overweight women with impaired fasting glucose: A randomised controlled trial.

AIM: Intra-pancreatic fat deposition (IPFD) while hypothesised to impair beta-cell function, its impact on alpha-cells remains unclear. We evaluated the association between IPFD and markers of pancreatic cells function using whey protein. METHODS: Twenty overweight women with impaired fasting glucose (IFG) and low or high IPFD (<4.66% vs ≥4.66%) consumed 3 beverage treatments: 0 g (water control), 12.5 g (low-dose) and 50.0 g (high-dose) whey protein, after an overnight fast, in randomised order. Blood glucose, insulin, C-peptide, glucagon, gastric-inhibitory polypeptide (GIP), glucagon-like peptide-1 (GLP-1) and amylin were analysed postprandially over 4 h. Incremental area-under-the-curve (iAUC), incremental maximum concentration (iCmax), and time to maximum concentration (Tmax) for these were compared between IPFD groups using repeated measures linear mixed models, also controlled for age (pcov). RESULTS: iAUC and iCmax glucose and insulin while similar between the two IPFD groups, high IPFD and ageing contributed to higher postprandial glucagon (iAUC: p = 0.012; pcov = 0.004; iCmax: p = 0.069; pcov = 0.021) and GLP-1 (iAUC: p = 0.006; pcov = 0.064; iCmax: p = 0.011; pcov = 0.122) concentrations. CONCLUSION: In our cohort, there was no evidence that IPFD impaired protein-induced insulin secretion. Conversely, IPFD may be associated with increased protein-induced glucagon secretion, a novel observation which warrants further investigation into its relevance in the pathogenesis of dysglycaemia and type-2 diabetes.

Effect of a Higher-Protein Nut versus Higher-Carbohydrate Cereal Enriched Diet on the Gut Microbiomes of Chinese Participants with Overweight and Normoglycaemia or Prediabetes in the Tu Ora Study.

Global increases in metabolic disorders such as type 2 diabetes (T2D), especially within Asian populations, highlight the need for novel approaches to dietary intervention. The Tu Ora study previously evaluated the effects on metabolic health of including a nut product into the diet of a New Zealand cohort of Chinese participants with overweight and normoglycaemia or prediabetes through a 12-week randomised, parallel-group clinical trial. In this current study, we compared the impact of this higher-protein nut bar (HP-NB) versus a higher-carbohydrate cereal bar (HC-CB) on the faecal microbiome by employing both 16S rRNA gene amplicon and shotgun metagenomic sequencing of pre- and post-intervention pairs from 84 participants. Despite the higher fibre, protein, and unsaturated fat content of nuts, there was little difference between dietary groups in gut microbiome composition or functional potential, with the bacterial phylum Firmicutes dominating irrespective of diet. The lack of observed change suggests the dietary impact of the bars may have been insufficient to affect the gut microbiome. Manipulating the interplay between the diet, microbiome, and metabolic health may require a more substantial and/or prolonged dietary perturbation to generate an impactful modification of the gut ecosystem and its functional potential to aid in T2D risk reduction.

The Role of Bovine and Non-Bovine Milk in Cardiometabolic Health: Should We Raise the "Baa"?

Although causality is yet to be confirmed, a considerable volume of research has explored the relationships between cow milk consumption, type II diabetes, and cardiovascular disease. Contrastingly, it has not been comprehensively examined whether milk of non-bovine origin can provide cardiometabolic protection. This narrative review outlines the marked differences in macronutrient composition, particularly protein and lipid content, and discusses how whole milk product (and individual milk ingredients) from different species could impact cardiometabolic health. There is some data, although primarily from compositional analyses, animal studies, and acute clinical trials, that non-bovine milk (notably sheep and goat milk) could be a viable substitute to cow milk for the maintenance, or enhancement, of cardiometabolic health. With a high content of medium-chain triglycerides, conjugated linoleic acid, leucine, and essential minerals, sheep milk could assist in the prevention of metabolic-related disorders. Similarly, albeit with a lower content of such functional compounds relative to sheep milk, goat and buffalo milk could be plausible counterparts to cow milk. However, the evidence required to generate nutritional recommendations for 'non-bovine milk' is currently lacking. Longer-term randomised controlled trials must assess how the bioactive ingredients of different species' milks collectively influence biomarkers of, and subsequently incidence of, cardiometabolic health.

Acute Effects of Kawakawa (Piper excelsum) Intake on Postprandial Glycemic and Insulinaemic Response in a Healthy Population.

Background: Piper excelsum (kawakawa) is an endemic shrub of Aotearoa, New Zealand, of cultural and medicinal importance to Maori. Its fruits and leaves are often consumed. These tissues contain several compounds that have been shown to be biologically active and which may underpin its putative health-promoting effects. The current study investigates whether kawakawa tea can modulate postprandial glucose metabolism. Methods: We report a pilot three-arm randomized crossover study to assess the bioavailability of kawakawa tea (BOKA-T) in six male participants with each arm having an acute intervention of kawakawa tea (4 g/250 mL water; 1 g/250 mL water; water) and a follow-up two-arm randomized crossover study to assess the impact of acute kawakawa tea ingestion on postprandial glucose metabolism in healthy human volunteers (TOAST) (4 g/250 mL water; and water; n = 30 (15 male and 15 female)). Participants consumed 250 mL of kawakawa tea or water control within each study prior to consuming a high-glycemic breakfast. Pre- and postprandial plasma glucose and insulin concentrations were measured, and the Matsuda index was calculated to measure insulin sensitivity. Results: In the BOKA-T study, lower plasma glucose (p < 0.01) and insulin (p < 0.01) concentrations at 60 min were observed after consumption of a high-dose kawakawa tea in comparison to low-dose or water. In the TOAST study, only plasma insulin (p = 0.01) was lower at 60 min in the high-dose kawakawa group compared to the control group. Both studies showed a trend towards higher insulin sensitivity in the high-dose kawakawa group compared to water only. Conclusions: Consuming kawakawa tea may modulate postprandial glucose metabolism. Further investigations with a longer-term intervention study are warranted.

Fatty Pancreas and Cardiometabolic Risk: Response of Ectopic Fat to Lifestyle and Surgical Interventions.

Ectopic fat accumulation in non-adipose organs, such as the pancreas and liver, is associated with an increased risk of cardiometabolic disease. While clinical trials have focused on interventions to decrease body weight and liver fat, ameliorating pancreatic fat can be crucial but successful intervention strategies are not yet defined. We identified twenty-two published studies which quantified pancreatic fat during dietary, physical activity, and/or bariatric surgery interventions targeted at body weight and adipose mass loss alongside their subsequent effect on metabolic outcomes. Thirteen studies reported a significant decrease in body weight, utilising weight-loss diets (n = 2), very low-energy diets (VLED) (n = 2), isocaloric diets (n = 1), a combination of diet and physical activity (n = 2), and bariatric surgery (n = 5) including a comparison with VLED (n = 1). Surgical intervention achieved the largest decrease in pancreatic fat (range: -18.2% to -67.2%) vs. a combination of weight-loss diets, isocaloric diets, and/or VLED (range: -10.2% to -42.3%) vs. diet and physical activity combined (range: -0.6% to -3.9%), with a concurrent decrease in metabolic outcomes. While surgical intervention purportedly is the most effective strategy to decrease pancreas fat content and improve cardiometabolic health, the procedure is invasive and may not be accessible to most individuals. Given that dietary intervention is the cornerstone for the prevention of adverse metabolic health, the alternative approaches appear to be the use of weight-loss diets or VLED meal replacements, which are shown to decrease pancreatic fat and associated cardiometabolic risk.

Exploring the Chemical Space of Kawakawa Leaf (Piper excelsum).

The chemical profiles of kawakawa (Piper excelsum) leaves were analysed through targeted and non-targeted LC-MS/MS. The phytochemical profile was obtained for both aqueous extracts representative of kawakawa tea and methanolic extracts. Sixty-four compounds were identified from eight leaf sources including phenylpropanoids, lignans, flavonoids, alkaloids and amides. Eight of these compounds were absolutely quantified. The chemical content varied significantly by leaf source, with two commercially available sources of dried kawakawa leaves being relatively high in phenylpropanoids and flavonoids compared with field-collected fresh samples that were richer in amides, alkaloids and lignans. The concentrations of pharmacologically active metabolites ingested from the traditional consumption of kawakawa leaf as an aqueous infusion, or from novel use as a seasoning, are well below documented toxicity thresholds.

Weight cycling practices in sport: A risk factor for later obesity?

Weight cycling, repeated cycles of weight loss and weight regain over time, is commonplace amongst many population groups. Although the effect of weight cycling on future obesity and cardiometabolic risk is still hotly debated, evidence does indicate that individuals who were normal weight prior to weight cycling are more susceptible to its adverse consequences than those who were overweight or with obesity. Athletes, and particularly those who compete in the so-called weight-sensitive sports, are prone to dieting and weight cycling practice owing to the competitive advantage to be gained from manipulating their body weight. However, in comparison with the general population, athletes tend to be leaner and weight loss phases more rapid and superimposed on a background of a high level of physical activity. In this context, it can be questioned whether weight cycling in this subpopulation will indeed increase risk for future obesity. It is perhaps surprising that despite recognition that athletes commonly partake in weight cycling during their career, studies are scarce and firm conclusions regarding the effect of this practice on future cardiometabolic risk remain to be drawn. In this review, we examine weight cycling prevalence and strategies in athletes and the current evidence relating to its short- and long-term consequences. In addition, a conceptual framework relating the dynamics of weight loss and recovery to athlete characteristics will be discussed, highlighting the need for well-controlled, prospective studies in this specific subpopulation.

Objectively Measured Physical Activity Is Associated With Body Composition and Metabolic Profiles of Pacific and New Zealand European Women With Different Metabolic Disease Risks.

Objective: To assess associations between physical activity (PA), body composition, and biomarkers of metabolic health in Pacific and New Zealand European (NZE) women who are known to have different metabolic disease risks. Methods: Pacific (n = 142) or NZE (n = 162) women aged 18-45 years with a self-reported body mass index (BMI) of either 18.5-25.0 kg⋅m-2 or ≥30.0 kg⋅m-2 were recruited and subsequently stratified as either low (<35%) or high (≥35%) BF%, with approximately half of each group in either category. Seven-day accelerometery was used to assess PA levels. Fasting blood was analysed for biomarkers of metabolic health, and whole body dual-energy X-ray absorptiometry (DXA) was used to estimate body composition. Results: Mean moderate-to-vigorous physical activity (MVPA; min⋅day-1) levels differed between BF% (p < 0.05) and ethnic (p < 0.05) groups: Pacific high- 19.1 (SD 15.2) and low-BF% 26.3 (SD 15.6) and NZE high- 30.5 (SD 19.1) and low-BF% 39.1 (SD 18.4). On average Pacific women in the low-BF% group engaged in significantly less total PA when compared to NZE women in the low-BF% group (133 cpm); no ethnic difference in mean total PA (cpm) between high-BF% groups were observed: Pacific high- 607 (SD 185) and low-BF% 598 (SD 168) and NZE high- 674 (SD 210) and low-BF% 731 (SD 179). Multiple linear regression analysis controlling for age and deprivation showed a significant inverse association between increasing total PA and fasting plasma insulin among Pacific women; every 100 cpm increase in total PA was associated with a 6% lower fasting plasma insulin; no significant association was observed in NZE women. For both Pacific and NZE women, there was an 8% reduction in fasting plasma insulin for every 10-min increase in MVPA (p ≤ 0.05). Conclusion: Increases in total PA and MVPA are associated with lower fasting plasma insulin, thus indicating a reduction in metabolic disease risk. Importantly, compared to NZE, the impact of increased total PA on fasting insulin may be greater in Pacific women. Considering Pacific women are a high metabolic disease risk population, these pre-clinical responses to PA may be important in this population; indicating promotion of PA in Pacific women should remain a priority.

Assessment of the Dose-Response Relationship between Meal Protein Content and Postprandial Thermogenesis: Effect of Sex and the Oral Contraceptive Pill.

Implementation of efficacious dietary interventions to regulate energy balance requires understanding of the determinants of individual response. To date, information regarding individual variability in response to elevated meal protein content is lacking. This study investigates whether sex and/or oral contraceptive pill (OCP) use play a role in the response to elevated meal protein in 21 healthy young adults (seven men, seven women not taking OCP, and seven women who were OCP users). Participants consumed each of three standardized isocaloric (590 kcal) meals of differing protein content (11, 23, 31% kcal protein). Resting energy expenditure (EE), respiratory quotient (RQ), hunger and satiety were measured at baseline (fasting) and during 180 min postprandial. Whilst significant dose-response increases in EE were observed in men, meal protein-induced EE in women without OCP reached a maximum at <23% protein. Women taking OCP reported lower postprandial fullness than women without OCP, despite similar body size, but also, most notably, no significant difference in EE response between any of the meals. Whilst the mechanisms underpinning this thermogenic inflexibility in response across a wide-range (three-fold) of protein meal content require further investigation, this highlights the need for careful consideration of factors that may influence an individual's metabolic response to dietary interventions aimed at optimising postprandial thermogenesis for body weight regulation.

Collateral fattening in body composition autoregulation: its determinants and significance for obesity predisposition.

Collateral fattening refers to the process whereby excess fat is deposited as a result of the body's attempt to counter a deficit in lean mass through overeating. Its demonstration and significance to weight regulation and obesity can be traced to work on energy budget strategies in growing mammals and birds, and to men recovering from experimental starvation. The cardinal features of collateral fattening rests upon (i) the existence of a feedback system between lean tissue and appetite control, with lean tissue deficit driving hyperphagia, and (ii) upon the occurrence of a temporal desynchronization in the recovery of body composition, with complete recovery of fat mass preceeding that of lean mass. Under these conditions, persistent hyperphagia driven by the need to complete the recovery of lean tissue will result in the excess fat deposition (hence collateral fattening) and fat overshooting. After reviewing the main lines of evidence for the phenomenon of collateral fattening in body composition autoregulation, this article discusses the causes and determinants of the desynchronization in fat and lean tissue recovery leading to collateral fattening and fat overshooting, and points to their significance in the mechanisms by which dieting, developmental programming and sedentariness predispose to obesity.

Energy Cost of Standing in a Multi-Ethnic Cohort: Are Energy-Savers a Minority or the Majority?

BACKGROUND: The disease risks associated with sedentary behavior are now firmly established, and consequently there is much interest in methods of increasing low-intensity physical activity. In this context, it is a widely held belief that altering posture allocation can modify energy expenditure (EE) to impact upon body weight regulation and health. However, we recently showed the existence of two distinct phenotypes pertaining to the energy cost of standing-with the majority of a Caucasian cohort showing no sustained increase in EE during standing relative to sitting. Here we investigated whether this phenomenon is also observed across a multi-ethnic male cohort. OBJECTIVE: To determine the magnitude and time-course of changes in EE and respiratory quotient (RQ) during steady-state standing versus sitting, and to explore inter-individual variability in these responses across 4 ethnic groups (European, Indian, Chinese, African). DESIGN: Min-by-min monitoring using posture-adapted ventilated-hood indirect calorimetry was conducted in 35 healthy, men (20-43 years) during 10 min of steady-state standing versus sitting comfortably. RESULTS: 69% of subjects showed little or no increase (<5%) in EE during standing compared to sitting (energy savers). Furthermore, the proportion of energy savers did not significantly differ between ethnic groups, despite ethnic differences in anthropometry; with body weight as the primary predictor of the energy cost of standing maintenance (r2 = 0.30, p = 0.001). CONCLUSION: Our results indicate that the majority of individuals in a multi-ethnic cohort display a postural energy-saver phenotype. The mechanisms by which the large majority of individuals appear to maintain sitting and standing postures at the same energetic cost remains to be elucidated but is of considerable importance to our understanding of the spontaneous physical activity compartment of EE and its potential as a target for weight regulation.

Posture Allocation Revisited: Breaking the Sedentary Threshold of Energy Expenditure for Obesity Management.

There is increasing recognition that low-intensity physical activities of daily life play an important role in achieving energy balance and that their societal erosion through substitution with sedentary (mostly sitting) behaviors, whether occupational or for leisure, impact importantly on the obesity epidemic. This has generated considerable interest for better monitoring, characterizing, and promoting countermeasures to sedentariness through a plethora of low-level physical activities (e.g., active workstations, standing desks, sitting breaks), amid the contention that altering posture allocation (lying, sitting, standing) can modify energy expenditure to impact upon body weight regulation and health. In addressing this contention, this paper first revisits the past and more recent literature on postural energetics, with particular emphasis on potential determinants of the large inter-individual variability in the energy cost of standing and the impact of posture on fat oxidation. It subsequently analyses the available data pertaining to various strategies by which posture allocations, coupled with light physical activity, may increase energy expenditure beyond the sedentary threshold, and their relevance as potential targets for obesity management.