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Horner KM, Schubert MM, Desbrow B, Byrne NM, King NA. Acute exercise and gastric emptying: a meta-analysis and implications for appetite control. Sports Med 2016; 45:659-78. [PMID: 25398225 DOI: 10.1007/s40279-014-0285-4] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND Gastric emptying (GE) could influence exercise-induced changes in appetite and energy intake. GE also could contribute to changes in gastric symptoms and the availability of nutrients during exercise, which will subsequently affect performance. OBJECTIVE The objective of this review was to determine the effects of acute exercise on GE using a systematic review and meta-analysis. The most common parameters to determine GE were selected, consisting of half-emptying time and volume emptied. Oral-caecal transit time (OCTT) was also examined. DATA SOURCES Research databases (PubMed, Scopus, Google Scholar, EBSCOhost, SPORTDiscus) were searched through November 2013 for original studies, abstracts, theses and dissertations that examined the influence of acute exercise on GE. STUDY SELECTION Studies were included if they evaluated GE or OCTT during and/or after exercise and involved a resting control trial. STUDY APPRAISAL AND SYNTHESIS Initially, 195 studies were identified. After evaluation of study characteristics and quality and validity, data from 20 studies (35 trials) involving 221 participants (157 men; 52 women; 12 unknown) were extracted for meta-analysis. Random-effects meta-analyses were utilised for the three main outcome variables, and effect sizes (ES) are reported as Hedge's g due to numerous small sample sizes. RESULTS Random-effects modelling revealed non-significant and small/null main effect sizes for volume emptied (ES = 0.195; 95% CI -0.25 to 0.64), half-time (ES = -0.109, 95% CI -0.66 to 0.44) and OCTT (ES = 0.089; 95% CI -0.64 to 0.82). All analyses exhibited significant heterogeneity and numerous variables moderated the results. There was a dose response of exercise intensity; at lower intensities GE was faster, and at high exercise intensities GE was slower. Walking was associated with faster GE and cycling with slower GE. Greater volume of meal/fluid ingested, higher osmolality of beverage and longer exercise duration were also associated with slower GE with exercise. LIMITATIONS The major limitation is that the majority of studies utilised a liquid bolus administered pre-exercise to determine GE; the relationship to post-exercise appetite and energy intake remains unknown. Study populations were also generally active or trained individuals. Furthermore, our review was limited to English language studies and studies that utilised resting control conditions. CONCLUSIONS These results suggest that exercise intensity, mode, duration and the nature of meal/fluid ingested all influence GE during and after acute exercise. The relationship of GE parameters with appetite regulation after exercise remains largely unexplored. Further integrative studies combining GE and alterations in gut hormones, as well as in populations such as overweight and obese individuals are needed.
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Affiliation(s)
- Katy M Horner
- School of Exercise and Nutrition Sciences and Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia
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Littlejohn NK, Grobe JL. Opposing tissue-specific roles of angiotensin in the pathogenesis of obesity, and implications for obesity-related hypertension. Am J Physiol Regul Integr Comp Physiol 2015; 309:R1463-73. [PMID: 26491099 DOI: 10.1152/ajpregu.00224.2015] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 10/15/2015] [Indexed: 12/24/2022]
Abstract
Metabolic disease, specifically obesity, has now become the greatest challenge to improving cardiovascular health. The renin-angiotensin system (RAS) exists as both a circulating hormone system and as a local paracrine signaling mechanism within various tissues including the brain, kidney, and adipose, and this system is strongly implicated in cardiovascular health and disease. Growing evidence also implicates the RAS in the control of energy balance, supporting the concept that the RAS may be mechanistically involved in the pathogenesis of obesity and obesity hypertension. Here, we review the involvement of the RAS in the entire spectrum of whole organism energy balance mechanisms, including behaviors (food ingestion and spontaneous physical activity) and biological processes (digestive efficiency and both aerobic and nonaerobic resting metabolic rates). We hypothesize that opposing, tissue-specific effects of the RAS to modulate these various components of energy balance can explain the apparently paradoxical results reported by energy-balance studies that involve stimulating, versus disrupting, the RAS. We propose a model in which such opposing and tissue-specific effects of the RAS can explain the failure of simple, global RAS blockade to result in weight loss in humans, and hypothesize that obesity-mediated uncoupling of endogenous metabolic rate control mechanisms can explain the phenomenon of obesity-related hypertension.
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Affiliation(s)
- Nicole K Littlejohn
- Department of Pharmacology, the Obesity Research and Education Initiative, the Fraternal Order of Eagles' Diabetes Research Center, the François M. Abboud Cardiovascular Research Center, and the Center for Hypertension Research, University of Iowa, Iowa City, Iowa
| | - Justin L Grobe
- Department of Pharmacology, the Obesity Research and Education Initiative, the Fraternal Order of Eagles' Diabetes Research Center, the François M. Abboud Cardiovascular Research Center, and the Center for Hypertension Research, University of Iowa, Iowa City, Iowa
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Abstract
Sedentary lifestyle is linked with poor health, most commonly obesity and associated disorders, the corollary being that exercise offers a preventive strategy. However, the scope of exercise biology extends well beyond energy expenditure and has emerged as a great 'polypill', which is safe, reliable and cost-effective not only in disease prevention but also treatment. Biological mechanisms by which exercise influences homeostasis are becoming clearer and involve multi-organ systemic adaptations. Most of the elements of a modern lifestyle influence the indigenous microbiota but few studies have explored the effect of increased physical activity. While dietary responses to exercise obscure the influence of exercise alone on gut microbiota, professional athletes operating at the extremes of performance provide informative data. We assessed the relationship between extreme levels of exercise, associated dietary habits and gut microbiota composition, and discuss potential mechanisms by which exercise may exert a direct or indirect influence on gut microbiota.
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Affiliation(s)
- Orla O’Sullivan
- Teagasc Food Research Center; Moorepark; Fermoy; Cork, Ireland
| | - Owen Cronin
- Department of Medicine; University College Cork; National University of Ireland; Cork, Ireland
| | - Siobhan F Clarke
- Teagasc Food Research Center; Moorepark; Fermoy; Cork, Ireland,Alimentary Pharmabiotic Center; University College Cork; Cork, Ireland
| | | | - Micheal G Molloy
- Department of Medicine; University College Cork; National University of Ireland; Cork, Ireland
| | - Fergus Shanahan
- Department of Medicine; University College Cork; National University of Ireland; Cork, Ireland,Alimentary Pharmabiotic Center; University College Cork; Cork, Ireland,Correspondence to: Fergus Shanahan;
| | - Paul D Cotter
- Teagasc Food Research Center; Moorepark; Fermoy; Cork, Ireland,Alimentary Pharmabiotic Center; University College Cork; Cork, Ireland
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54
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Consistency in compensatory eating responses following acute exercise in inactive, overweight and obese women. Br J Nutr 2015; 113:1170-7. [PMID: 25778833 DOI: 10.1017/s000711451500046x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
It is often assumed that some individuals reliably increase energy intake (EI) post-exercise ('compensators') and some do not ('non-compensators'), leading researchers to examine the characteristics that distinguish these two groups. However, it is unclear whether EI post-exercise is stable over time. The present study examined whether compensatory eating responses to a single exercise bout are consistent within individuals across three pairs of trials. Physically inactive, overweight/obese women (n 28, BMI 30·3 (SD 2·9) kg/m²) participated in three pairs of testing sessions, with each pair consisting of an exercise (30 min of moderate-intensity walking) and resting testing day. EI was measured using a buffet meal 1 h post-exercise/rest. For each pair, the difference in EI (EIdiff = EIex - EIrest) was calculated, where EIex is the EI of the exercise session and EIrest is the EI of the resting session, and women were classified as a 'compensator' (EIex > EIrest) or 'non-compensator' (EIex ≤ EIrest). The average EI on exercise days (3328·0 (SD 1686·2) kJ) was similar to those on resting days (3269·4 (SD 1582·4) kJ) (P= 0·67). Although EI was reliable within individuals across the three resting days (intraclass correlation coefficient (ICC) 0·75, 95 % CI 0·60, 0·87; P< 0·001) and three exercise days (ICC 0·83, 95 % CI 0·70, 0·91; P< 0·001), the ICC for EIdiff across the three pairs of trials was low (ICC 0·20, 95 % CI -0·02, 0·45; P= 0·04), suggesting that compensatory eating post-exercise is not a stable construct. Moreover, the classification of 'compensators'/'non-compensators' was not reliable (κ = -0·048; P= 0·66). The results were unaltered when 'relative' EI was used, which considers the energy expenditure of the exercise/resting sessions. Acute compensatory EI following an exercise bout is not reliable in overweight women. Seeking to understand what distinguishes 'compensators' from 'non-compensators' based on a single eating episode post-exercise is not justified.
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MacLean PS, Wing RR, Davidson T, Epstein L, Goodpaster B, Hall KD, Levin BE, Perri MG, Rolls BJ, Rosenbaum M, Rothman AJ, Ryan D. NIH working group report: Innovative research to improve maintenance of weight loss. Obesity (Silver Spring) 2015; 23:7-15. [PMID: 25469998 PMCID: PMC5841916 DOI: 10.1002/oby.20967] [Citation(s) in RCA: 365] [Impact Index Per Article: 40.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Accepted: 10/21/2014] [Indexed: 12/11/2022]
Abstract
OBJECTIVES The National Institutes of Health, led by the National Heart, Lung, and Blood Institute, organized a working group of experts to discuss the problem of weight regain after weight loss. A number of experts in integrative physiology and behavioral psychology were convened with the goal of merging their perspectives regarding the barriers to scientific progress and the development of novel ways to improve long-term outcomes in obesity therapeutics. The specific objectives of this working group were to: (1) identify the challenges that make maintaining a reduced weight so difficult; (2) review strategies that have been used to improve success in previous studies; and (3) recommend novel solutions that could be examined in future studies of long-term weight control. RESULTS Specific barriers to successful weight loss maintenance include poor adherence to behavioral regimens and physiological adaptations that promote weight regain. A better understanding of how these behavioral and physiological barriers are related, how they vary between individuals, and how they can be overcome will lead to the development of novel strategies with improved outcomes. CONCLUSIONS Greater collaboration and cross-talk between physiological and behavioral researchers is needed to advance the science and develop better strategies for weight loss maintenance.
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Affiliation(s)
- Paul S. MacLean
- Department of Medicine, Division of Endocrinology, Metabolism, and Diabetes, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Rena R. Wing
- Department of Psychiatry & Human Behavior, Alpert Medical School of Brown University, Providence, Rhode Island, USA
| | - Terry Davidson
- Department of Psychology, American University, Washington, DC, USA
| | - Leonard Epstein
- Department of Pediatrics, University of Buffalo, Buffalo, New York, USA
| | - Bret Goodpaster
- Florida Hospital Translational Institute for Metabolism and Diabetes and Sanford Burnham Medical Research Institute, Orlando, Florida, USA
| | - Kevin D. Hall
- Laboratory of Biological Modeling, Integrative Physiology Section, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland, USA
| | - Barry E. Levin
- Department of Neurology and Neurosciences, Rutgers-New Jersey Medical School, Neurology Service, East Orange VA Medical Center, East Orange, New Jersey, USA
| | - Michael G. Perri
- College of Public Health and Health Professions, Department of Clinical and Health Psychology, University of Florida, Gainesville, Florida, USA
| | - Barbara J. Rolls
- Department of Nutritional Sciences, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Michael Rosenbaum
- Department of Pediatrics, Columbia University, New York, New York, USA
| | | | - Donna Ryan
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, Louisiana, USA
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Hopkins M, Gibbons C, Caudwell P, Webb DL, Hellström PM, Näslund E, Blundell JE, Finlayson G. Fasting Leptin Is a Metabolic Determinant of Food Reward in Overweight and Obese Individuals during Chronic Aerobic Exercise Training. Int J Endocrinol 2014; 2014:323728. [PMID: 24734042 PMCID: PMC3966321 DOI: 10.1155/2014/323728] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Revised: 01/15/2014] [Accepted: 01/18/2014] [Indexed: 01/28/2023] Open
Abstract
Changes in food reward have been implicated in exercise-induced compensatory eating behaviour. However, the underlying mechanisms of food reward, and the physiological correlates of exercise-induced changes in food reward, are unknown. Methods. Forty-six overweight and obese individuals completed 12 weeks of aerobic exercise. Body composition, food intake, and fasting metabolic-related hormones were measured at baseline, week six, and postintervention. On separate days, the reward value of high-and-low-fat food (explicit liking and implicit wanting) was also assessed at baseline, week six, and postintervention. Results. Following the intervention, FM, FFM, and VO2peak improved significantly, while fasting leptin decreased. However, food intake or reward did not change significantly. Cross-sectional analyses indicated that FM (P = 0.022) and FFM (P = 0.046) were associated with explicit liking for high-fat food, but implicit wanting was associated with FM only (P = 0.005). Fasting leptin was associated with liking (P = 0.023) and wanting (P = 0.021) for high-fat food. Furthermore, a greater exercise-induced decline in fasting leptin was associated with increased liking (P = 0.018). Conclusion. These data indicate that food reward has a number of physiological correlates. In particular, fasting leptin appears to play an active role in mediating food reward during exercise-induced weight loss.
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Affiliation(s)
- Mark Hopkins
- Academy of Sport and Physical Activity, Faculty of Health and Wellbeing, Sheffield Hallam University, Sheffield S10 2BP, UK
- Institute of Psychological Sciences, Faculty of Medicine and Health, University of Leeds, Leeds LS2 9JT, UK
- *Mark Hopkins:
| | - Catherine Gibbons
- Institute of Psychological Sciences, Faculty of Medicine and Health, University of Leeds, Leeds LS2 9JT, UK
| | - Phillipa Caudwell
- Institute of Psychological Sciences, Faculty of Medicine and Health, University of Leeds, Leeds LS2 9JT, UK
| | - Dominic-Luc Webb
- Department of Medical Sciences, Gastroenterology and Hepatology, Uppsala University, Uppsala, Sweden
| | - Per M. Hellström
- Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - Erik Näslund
- Division of Surgery, Department of Clinical Sciences, Danderyd Hospital, Karolinska Institute, Stockholm, Sweden
| | - John E. Blundell
- Institute of Psychological Sciences, Faculty of Medicine and Health, University of Leeds, Leeds LS2 9JT, UK
| | - Graham Finlayson
- Institute of Psychological Sciences, Faculty of Medicine and Health, University of Leeds, Leeds LS2 9JT, UK
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