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Acute responses of hepatic fat content to consuming fat, glucose and fructose alone and in combination in non-obese non-diabetic individuals with non-alcoholic fatty liver disease.
Kovar, J, Dusilova, T, Sedivy, P, Bruha, R, Gottfriedova, H, Pavlikova, P, Pitha, J, Smid, V, Drobny, M, Dezortova, M, et al
Journal of physiology and pharmacology : an official journal of the Polish Physiological Society. 2021;72(1)
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Non-alcoholic fatty liver disease (NAFLD) is often associated with obesity or conditions related to obesity, such as type 2 diabetes. Steatosis is one of the four stages of NAFLD, where there is a small layer of fat build-up on the liver. Currently, one in three people in the UK has simple fatty liver or steatosis. A fascinating aspect of this study is exploring the long-term cumulative effects of daily fat intake when consumed with glucose or fructose and in the pathogenesis of steatosis. In this randomised controlled study, the researchers examined the immediate impact of high-fat loads on hepatic fat content (HFC) when administered with glucose or fructose in eight healthy overweight males with NFALD. The experiments lasted only eight hours. HFC was only transiently elevated by co-administration of glucose and high-fat loading. However, fructose co-administration with multiple high-fat loads promoted HFC. Small sample size and short duration are the limitations of this study. Long-term robust studies are needed to confirm the findings. Yet, healthcare professionals can use this study to distinguish between the immediate effects of fructose or glucose when combined with multiple doses of high fat on HFC in healthy and NAFLD subjects.
Abstract
We have recently demonstrated that a high-fat load can induce immediate increase in hepatic fat content (HFC) and that such an effect can be modified differently by co-administration of fructose or glucose in healthy subjects. Therefore, we addressed the question how consumption of these nutrients affects changes in HFC in subjects with non-alcoholic fatty liver disease (NAFLD). Eight male non-obese non-diabetic patients with NAFLD underwent 6 experiments each lasting 8 hours: 1. fasting, 2. high-fat load (150 g of fat (dairy cream) at time 0), 3. glucose (three doses of 50 g at 0, 2, and 4 hours), 4. high-fat load with three doses of 50 g of glucose, 5. fructose (three doses of 50 g at 0, 2, and 4 hours), 6. high-fat load with three doses of 50 g of fructose. HFC was measured using magnetic resonance spectroscopy prior to meal administration and 3 and 6 hours later. Plasma triglycerides, non-esterified fatty acids, glucose and insulin were monitored throughout each experiment. HFC increased by 10.4 ± 6.9% six hours after a high-fat load and by 15.2 ± 12.5% after high-fat load with fructose. When co-administering glucose with fat, HFC rose only transiently to return to baseline at 6 hours. Importantly, NAFLD subjects accumulated almost five times more fat in their livers than healthy subjects with normal HFC. Consumption of a high-fat load results in fat accumulation in the liver of NAFLD patients. Fat accumulation after a fat load is diminished by glucose but not fructose co-administration.
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Referral to Slimming World in UK Stop Smoking Services (SWISSS) versus stop smoking support alone on body weight in quitters: results of a randomised controlled trial.
Lycett, D, Aveyard, P, Farmer, A, Lewis, A, Munafò, M
BMJ open. 2020;10(1):e032271
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Weight gain is a well-known consequence of smoking cessation. The aim of this study was to compare standard stop smoking behavioural support with an intervention that, in addition to providing standard stop smoking support, included personalised weight management support, provided by Slimming World. This study is a parallel group, individually randomised controlled trial. Participants were randomised (1:1) to usual care or Slimming World with usual care. Stop smoking advisors were unaware of the randomisation sequence. Results showed that referral to the Slimming World programme plus usual stop smoking support achieved significantly less weight gain than usual stop smoking support alone. Furthermore, percentage quit was no worse in the treatment than the control group. Authors conclude that referral to a behavioural weight loss programme may be a pragmatic option within stop smoking clinics.
Abstract
INTRODUCTION Most people who stop smoking gain weight. Dietary modification may seem an obvious solution, but food restriction may increase cigarette craving and smoking relapse. TRIAL DESIGN An unblinded parallel randomised controlled trial. METHODS Participants were adult smokers with a body mass index greater or equal to 23 kg/m2. Setting was National Health Service commissioned Stop Smoking Services, interventions were referral to a commercial weight management programme, plus stop smoking support (treatment group), compared with stop smoking support alone (control group). Objective was to compare weight change between interventions in smoking abstainers and not abstinent rates in all. Primary outcome was change in weight (kg) at 12 weeks. Randomisation sequence was computer generated and concealed until allocation. RESULTS Seventy-six participants were recruited, 37 were randomised to the treatment group and 39 to the control group. Change in weight was analysed in long-term abstainers (13 treatment, 14 control) only because the aim was to prevent weight gain associated with smoking cessation. Abstinence was analysed on an intention-to-treat basis (37 treatment, 39 control). At 12 weeks weight gain was less in the treatment than the control group with an adjusted mean difference of -2.3 kg 95% CI (-4.4 to -0.1). Craving scores were lower (Mood and Physical Symptoms Scale craving domain -1.6 (-2.7 to -0.5)) and quit rates were higher in the treatment than the control group (32% vs 21%), although the trial was not powered to superiority in cravings and quit rates. No adverse events or side effects were reported. CONCLUSION In people who are obese and want to quit smoking, these data provide modest encouragement that providing weight management at the time of quitting may be helpful. Those who are not obese, but who are informed about potential weight gain during their quit attempt, were uninterested in a weight management programme. TRIAL REGISTRATION NUMBER ISRCTN65705512.
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Effect of Supplemental Parenteral Nutrition Versus Enteral Nutrition Alone on Clinical Outcomes in Critically Ill Adult Patients: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.
Alsharif, DJ, Alsharif, FJ, Aljuraiban, GS, Abulmeaty, MMA
Nutrients. 2020;12(10)
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For individuals who are critically ill and cannot eat, the use of a tube through the mouth is the preferred way to ensure nutrition needs are met. However, complications such as diarrhoea and vomiting often means that these individuals still do not achieve optimal nutrition. In these instances, giving individuals nutrients directly into a vein alongside the feeding tube is an option to ensure they do not become nutrient deficient. This is known as a combination of enteral and parenteral nutrition. However, studies on the use of this combination are limited. This systematic review and meta-analysis of 5 studies aimed to determine the effects of a combination of enteral and parenteral feeding on clinical outcomes compared to a feeding tube alone. The results showed that compared to enteral feeding alone the combination decreased infections and intensive care unit (ICU) mortality. There was a very small effect on duration of ventilation and no effects were seen on length of hospital stay nor length of ICU stay. It was concluded that enteral feeding alone is insufficient to meet the nutritional needs of critically ill patients. Supplementing in parenteral nutrition may be of benefit to these individuals and help decrease infections and improve ICU mortality. This study could be used by healthcare professionals to understand that the health of patients who are being fed through a tube may be compromised through malnutrition and that supplemental ways of getting more nutrients into these individuals is of importance.
Abstract
Enteral nutrition (EN) is considered the first feeding route for critically ill patients. However, adverse effects such as gastrointestinal complications limit its optimal provision, leading to inadequate energy and protein intake. We compared the clinical outcomes of supplemental parenteral nutrition added to EN (SPN + EN) and EN alone in critically ill adults. Electronic databases restricted to full-text randomized controlled trials available in the English language and published from January 1990 to January 2019 were searched. The risk of bias was evaluated using the Jadad scale, and the meta-analysis was conducted using the MedCalc software. A total of five studies were eligible for inclusion in the systematic review and meta-analysis. Compared to EN alone, SPN + EN decreased the risk of nosocomial infections (relative risk (RR) = 0.733, p = 0.032) and intensive care unit (ICU) mortality (RR = 0.569, p = 0.030). No significant differences were observed between SPN + EN and EN in the length of hospital stay, hospital mortality, length of ICU stay, and duration of mechanical ventilation. In conclusion, when enteral feeding fails to fulfill the energy requirements in critically ill adult patients, SPN may be beneficial as it helps in decreasing nosocomial infections and ICU mortality, in addition to increasing energy and protein intakes with no negative effects on other clinical outcomes.
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Comparison of gut microbiota profile in celiac disease, non-celiac gluten sensitivity and irritable bowel syndrome: A systematic review.
Transeth, EL, Dale, HF, Lied, GA
The Turkish journal of gastroenterology : the official journal of Turkish Society of Gastroenterology. 2020;31(11):735-745
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Dysbiosis refers to a disturbance in the quantity and composition of the gut microbiota, and this shift in the microbiota profile is associated with a variety of GI disorders including celiac disease (CD), irritable bowel syndrome (IBS) and non-celiac gluten sensitivity (NCGS). There is no current clinical distinction between IBS and NCGS although it is hypothesised the characteristics of gut microbiota of these clinical presentations may overlap. The aim of this review is to analyse the gut microbiota profile in these three diagnoses. Thirteen trials were included in this review and show the bacterial composition of the gut microbiota of patients with CD and IBS shared many similarities when compared to healthy controls, including an overall reduction in microbial abundance. There were fewer similarities between IBS and NCGS, in part due to the lack of existing literature. Based on these findings, the authors suggest the bacterial profiles of patients CD and IBS share certain disease-specific trends. While the current data is limited, the authors hope these suggested trends influence further research to examine the overlap between NCGS and IBS and distinguish differential diagnostic and treatment plans.
Abstract
Gut microbiota is vital for human health. Shifts in the microbial diversity can affect bacterial function, and dysbiosis is associated with a variety of gastrointestinal disorders, including celiac disease (CD) and irritable bowel syndrome (IBS). The distinction between IBS and non-celiac gluten sensitivity (NCGS) is unclear, and it is conceivable that the gut microbiota profile of these patients may overlap. To our knowledge, no existing literature has evaluated the microbial characteristics in CD, IBS, and NCGS. Hence, this systematic review aims to compare the gut microbiota profile in these three diagnoses. A literature search was conducted in PubMed (Medline) until April 2019. Studies investigating bacterial diversity in the gut of patients with CD, IBS, and NCGS were eligible. Inclusion criteria were observational studies and randomized controlled trials reporting bacterial profile at baseline. Ninety-one articles were identified, of which 13 trials were eligible for inclusion. Overall, the bacterial composition of the gut microbiota of patients with CD and those with IBS shared the many similarities. The microbial richness was correspondingly reduced in these patient-groups compared with healthy controls, but this was not reported for NCGS. Our findings suggest that the bacterial profiles of patients with IBS and CD share certain disease-specific trends. Fewer similarities were observed between the bacterial profiles of patients with IBS and NCGS. Notably, the data are limited; thus, no solid conclusions can be made on the basis of these findings alone. The suggested trends can be a valuable basis for further research.
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Comparing eating behaviours, and symptoms of depression and anxiety between Spain and Greece during the COVID-19 outbreak: Cross-sectional analysis of two different confinement strategies.
Papandreou, C, Arija, V, Aretouli, E, Tsilidis, KK, Bulló, M
European eating disorders review : the journal of the Eating Disorders Association. 2020;28(6):836-846
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Stress and mental health problems which may be induced by restrictions imposed during the Covid-19 pandemic can lead to unhealthy eating habits. Restrictions have varied amongst countries and this cross-sectional analysis aimed to compare eating behaviours and symptoms of stress experienced by 1841 individuals in countries with differing lockdown measures. The results showed that individuals in the country with higher lockdown measures showed lower restraint in eating, they were more likely to overeat if they saw or smelt food and reported increased anxiety. However, they did not display depression or overeating when experiencing negative feelings. It was concluded that both countries had a high frequency of depression and anxiety. Higher restrictions were associated with greater anxiety, lower restraint and overeating when confronted with food. This paper could be used by healthcare professionals to recognise the need to include dietary advice when dealing with patients who are reporting anxiety during the current Covid-19 pandemic.
Abstract
OBJECTIVE We compared eating behaviours, and depressive and anxiety symptoms in two countries with different confinement strictness strategies and different levels of COVID-19 pandemic. METHOD A web-based cross-sectional survey was administered during and shortly after the COVID-19 related lockdown in Spain and Greece. Multivariable linear regression analyses were performed to identify country differences associated with eating behaviour, and symptoms of depression and anxiety. RESULTS This study included 1,002 responders in Spain and 839 in Greece. The mean ± SD of restraint, emotional and external eating was 2.5 ± 0.79, 2.1 ± 0.81 and 2.6 ± 0.65 in Spain, whereas 2.7 ± 0.85, 2.3 ± 0.99 and 2.9 ± 0.74 in Greece. Spanish participants had lower average scores of restraint and external eating compared to Greek participants (p < .001), but no difference was seen for emotional eating. In Spain, 13.6%, and 12.3% of the survey respondents reported moderate to severe depressive and anxiety symptoms, respectively, whereas in Greece the respective values were 18.8 and 13.2%. After adjusting for several risk factors, a higher prevalence of anxiety symptoms was observed in Spain compared to Greece (p = .001), but no difference was seen for depressive symptoms. CONCLUSIONS This study demonstrated high scores of inappropriate eating behaviours and a high frequency of depressive and anxiety symptoms in two Mediterranean countries during the COVID-19 outbreak. Our findings revealed that compared to Greek participants, Spanish participants, that faced more severe COVID-19 pandemic and stricter lockdown measures, were associated with lower restraint and external eating and increased anxiety symptoms, but not with depressive symptoms or emotional eating.
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Systematic review and meta-analysis of the associations of vegan and vegetarian diets with inflammatory biomarkers.
Menzel, J, Jabakhanji, A, Biemann, R, Mai, K, Abraham, K, Weikert, C
Scientific reports. 2020;10(1):21736
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A growing trend towards vegetarianism and veganism has emerged in the past few years. Evidence has led to the assumption that these diets may protect against chronic disease, and one potential mechanism is through the modulation of inflammatory biomarkers. The aim of this review was to investigate the associations of veganism and vegetarianism with inflammatory markers. From the 21 cross-sectional studies included in this study, both vegan and vegetarian diets were associated with lower levels of CRP compared to omnivores. There was no association with all other inflammatory markers. Based on these findings, the authors conclude there is evidence for both vegan and vegetarian diets reducing CRP, a major marker of low-grade inflammation. More research is needed as most inflammatory markers have only been investigated in single studies thus far.
Abstract
Plant-based diets like vegetarian or vegan diets might influence circulating levels of inflammatory biomarkers, thereby reducing the risk of chronic diseases. This systematic review and meta-analysis aimed to investigate the associations of veganism and vegetarianism with circulating inflammatory biomarkers in comparison to omnivores. Literature search was conducted in Pubmed and EMBASE until April 2020 and mean differences of biomarkers were assessed for: C-reactive protein (CRP), interleukin-6 (IL-6), interleukin-18 (IL-18), interleukin-1 receptor antagonist (IL-1 RA), tumor necrosis factor-alpha (TNF-ɑ), E-selectin, intercellular adhesion molecule-1 (ICAM-1), monocyte chemoattractant protein-1 (MCP-1), adiponectin, omentin-1 and resistin. Of initially identified 1073 publications, 21 cross-sectional studies met the inclusion criteria and were included in the systematic review and meta-analysis. Vegan diet was associated with lower levels of CRP compared to omnivores [mean difference - 0.54 mg/l, 95%-CI: - 0.79 to - 0.28, p < 0.0001]. This association was less pronounced in vegetarians [mean difference - 0.25 mg/l, 95%-CI: - 0.49 to 0.00, p = 0.05]. In patients with impaired kidney function, the association between vegetarian nutrition and CRP was much stronger with - 3.91 mg/l (95%-CI: - 5.23 to - 2.60; p < 0.0001). No substantial effects were observed for all other inflammatory biomarkers. Despite strong associations between CRP and a vegan or vegetarian diet were seen, further research is needed, as most inflammatory biomarkers were investigated only in single studies so far.
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Association between intake of non-sugar sweeteners and health outcomes: systematic review and meta-analyses of randomised and non-randomised controlled trials and observational studies.
Toews, I, Lohner, S, Küllenberg de Gaudry, D, Sommer, H, Meerpohl, JJ
BMJ (Clinical research ed.). 2019;364:k4718
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Consumption of non-sugar sweeteners (NSS) has recently increased due to an emphasis on a low sugar diet. However, the exact health effects of this switch are uncertain. The aim of this systematic review and meta-analysis of 56 randomised and non-randomised trials aimed to determine the health effects of NSS’s in adults and children. The results showed that amongst adults body weight, blood sugar, daily energy intake, and blood pressure were all lower when exposed to NSS’s. Other health measures such as cancer and neurological disorders remained unaffected. Amongst children blood sugar was significantly higher and a small increase in body mass index was also observed when exposed to NSS’s. It was concluded that most health outcomes were unaffected by NSS’s, and there appears to be no health benefits on a broad range of outcomes when switching from sugar. Potential harm from regular NSS consumption could not be ruled out from this study. Healthcare professionals could use this study to understand that recommending diets which switch from sugar to NSS’s may have limited health benefits.
Abstract
OBJECTIVE To assess the association between intake of non-sugar sweeteners (NSS) and important health outcomes in generally healthy or overweight/obese adults and children. DESIGN Systematic review following standard Cochrane review methodology. DATA SOURCES Medline (Ovid), Embase, Cochrane CENTRAL, WHO International Clinical Trials Registry Platform, Clinicaltrials.gov, and reference lists of relevant publications. ELIGIBILITY CRITERIA FOR SELECTING STUDIES Studies including generally healthy adults or children with or without overweight or obesity were eligible. Included study designs allowed for a direct comparison of no intake or lower intake of NSS with higher NSS intake. NSSs had to be clearly named, the dose had to be within the acceptable daily intake, and the intervention duration had to be at least seven days. MAIN OUTCOME MEASURES Body weight or body mass index, glycaemic control, oral health, eating behaviour, preference for sweet taste, cancer, cardiovascular disease, kidney disease, mood, behaviour, neurocognition, and adverse effects. RESULTS The search resulted in 13 941 unique records. Of 56 individual studies that provided data for this review, 35 were observational studies. In adults, evidence of very low and low certainty from a limited number of small studies indicated a small beneficial effect of NSSs on body mass index (mean difference -0.6, 95% confidence interval -1.19 to -0.01; two studies, n=174) and fasting blood glucose (-0.16 mmol/L, -0.26 to -0.06; two, n=52). Lower doses of NSSs were associated with lower weight gain (-0.09 kg, -0.13 to -0.05; one, n=17 934) compared with higher doses of NSSs (very low certainty of evidence). For all other outcomes, no differences were detected between the use and non-use of NSSs, or between different doses of NSSs. No evidence of any effect of NSSs was seen on overweight or obese adults or children actively trying to lose weight (very low to moderate certainty). In children, a smaller increase in body mass index z score was observed with NSS intake compared with sugar intake (-0.15, -0.17 to -0.12; two, n=528, moderate certainty of evidence), but no significant differences were observed in body weight (-0.60 kg, -1.33 to 0.14; two, n=467, low certainty of evidence), or between different doses of NSSs (very low to moderate certainty). CONCLUSIONS Most health outcomes did not seem to have differences between the NSS exposed and unexposed groups. Of the few studies identified for each outcome, most had few participants, were of short duration, and their methodological and reporting quality was limited; therefore, confidence in the reported results is limited. Future studies should assess the effects of NSSs with an appropriate intervention duration. Detailed descriptions of interventions, comparators, and outcomes should be included in all reports. SYSTEMATIC REVIEW REGISTRATION Prospero CRD42017047668.
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Changes in Anxiety and Depression Traits Induced by Energy Restriction: Predictive Value of the Baseline Status.
Rodriguez-Lozada, C, Cuervo, M, Cuevas-Sierra, A, Goni, L, Riezu-Boj, JI, Navas-Carretero, S, Milagro, FI, Martinez, JA
Nutrients. 2019;11(6)
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Anxiety and depression are among the most common mental health problems and are associated with obesity and other chronic illnesses. The number of these disorders has not been reduced despite the increased use of cognitive behavioural therapy and pharmacotherapy. Current evidence suggests diet quality as a modifiable risk factor for mental illnesses. Additional studies are required to investigate the effect of dietary patterns as well as weight loss on improving symptoms. The first aim of this study was to investigate the effect of weight loss on overweight and obese patients, using two calorie-restricted diets, on anxiety and depression symptoms. The second aim was to analyse the role of the baseline psychological features in predicting future weight loss. The study was a randomized, longitudinal, and controlled intervention trial which lasted for 16 weeks. The study indicates that weight loss via calorie-controlled diets could improve depression symptoms in obese and overweight patients. Participants that lost more weight showed a larger amelioration in depression symptoms. The study also suggests that greater anxiety symptoms at the beginning of the intervention could predict a higher weight loss. These results, in addition to the positive effect on body composition, show that weight loss could become part of a health improvement plan.
Abstract
Current evidence proposes diet quality as a modifiable risk factor for mental or emotional impairments. However, additional studies are required to investigate the effect of dietary patterns and weight loss on improving psychological symptoms. The aim of this investigation was to evaluate the effect of energy-restriction, prescribed to overweight and obese participants, on anxiety and depression symptoms, as well as the potential predictive value of some baseline psychological features on weight loss. Overweight and obese participants (n = 305) were randomly assigned for 16 weeks to two hypocaloric diets with different macronutrient distribution: a moderately high-protein (MHP) diet and a low-fat (LF) diet. Anthropometrical, clinical, psychological, and lifestyle characteristics were assessed at baseline and at the end of the intervention. The nutritional intervention evidenced that weight loss has a beneficial effect on trait anxiety score in women (β = 0.24, p = 0.03), depression score in all population (β = 0.15, p = 0.02), particularly in women (β = 0.22, p = 0.03) and in subjects who followed the LF diet (β = 0.22, p = 0.04). Moreover, weight loss could be predicted by anxiety status at baseline, mainly in women and in those who were prescribed a LF diet. This trial suggests that weight loss triggers an improvement in psychological traits, and that anxiety symptoms could predict those volunteers that benefit most from a balanced calorie-restricted intervention, which will contribute to individualized precision nutrition.
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Association between eating behaviour and diet quality: eating alone vs. eating with others.
Chae, W, Ju, YJ, Shin, J, Jang, SI, Park, EC
Nutrition journal. 2018;17(1):117
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Selecting foods for a day is easily influenced by the social environment and eating together or alone plays a big role in that decision. The study aims to evaluate the association between diet quality of the modern Korean adult population based on the eating behaviour and the socioeconomic factors that influence their diet quality. The study is a cross-sectional study which included 3365 men and 5258 women aged between 19 and 64 years. The study included demographic, socioeconomics, and health behaviour factors as covariates. Results indicate that diet quality is influence by eating behaviour. Authors observed that when Korean adults ate without a companion, their diet quality was significantly lower than those who consistently ate with others. Furthermore, from the higher education to lower education level, the diet quality declined when they eat alone. Authors conclude that many Korean adults are experiencing low diet quality when they eat alone. The study provides evidence to promote interventions to improve diet quality among the public.
Abstract
BACKGROUND To discover the association between eating alone and diet quality among Korean adults who eat alone measured by the mean adequacy ratio (MAR), METHODS The cross-sectional study in diet quality which was measured by nutrient intakes, indicated as MAR and nutrient adequacy ratio (NAR) with the Korean National Health and Nutrition Examination Survey (KNHANES) VI 2013-2015 data. Study population was 8523 Korean adults. Multiple linear regression was performed to identify the association between eating behaviour and MAR and further study analysed how socioeconomic factors influence the diet quality of those who eat alone. RESULTS We found that the diet quality of people who eat alone was lower than that of people who eat together in both male (β: - 0.110, p = 0.002) and female participants (β: - 0.069, p = 0.005). Among who eats alone, the socioeconomic factors that negatively influenced MAR with the living arrangement, education level, income levels, and various occupation classifications. CONCLUSIONS People who eat alone have nutrition intake below the recommended amount. This could lead to serious health problems not only to those who are socially disadvantaged but also those who are in a higher social stratum. Policy-makers should develop strategies to enhance diet quality to prevent potential risk factors.
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Whey protein consumption after resistance exercise reduces energy intake at a post-exercise meal.
Monteyne, A, Martin, A, Jackson, L, Corrigan, N, Stringer, E, Newey, J, Rumbold, PLS, Stevenson, EJ, James, LJ
European journal of nutrition. 2018;57(2):585-592
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Resistance exercise and post-exercise protein intake increase muscle building, and protein feeding has been shown to reduce energy intake in subsequent meals. The purpose of this study was to compare drinks containing carbohydrate (CHO, in the form of dextrose) and protein (PRO, as whey protein), consumed after resistance exercise on subsequent appetite and energy intake. 15 physically active, healthy males, who included resistance exercise in their exercise routine took part in this randomised double-blind study. After completing 50 min of leg resistance exercises they immediately ingested either PRO or CHO drink. 65 minutes after exercise they were offered a meal. The time spent eating and total energy intake were recorded, and subjects completed a questionnaire regarding their subjective appetite and sensory characteristics of the drink. The drink was provided in a randomised, double-blind manner. After the PRO drink participants consumed 10.3% less energy and eating rate was lower compared with the CHO drink. The PRO drink was perceived as creamier and thicker, the CHO drink as sweeter, more pleasant and more refreshing. Several plausible explanations exist as to why protein in drink form might be more satiating than carbohydrate: gastrointestinal appetite-related hormones; circulating amino acids; and the sensory profile of the drink. As no bloods were taken, these possible explanations could not be evaluated. The authors conclude that whilst the observed reduction in energy intake is unlikely to impair the energy provision required to optimise muscle synthesis, it may be beneficial for those individuals seeking to reduce body fat.
Abstract
PURPOSE Protein consumption after resistance exercise potentiates muscle protein synthesis, but its effects on subsequent appetite in this context are unknown. This study examined appetite and energy intake following consumption of protein- and carbohydrate-containing drinks after resistance exercise. METHODS After familiarisation, 15 resistance training males (age 21 ± 1 years, body mass 78.0 ± 11.9 kg, stature 1.78 ± 0.07 m) completed two randomised, double-blind trials, consisting of lower-body resistance exercise, followed by consumption of a whey protein (PRO 23.9 ± 3.6 g protein) or dextrose (CHO 26.5 ± 3.8 g carbohydrate) drink in the 5 min post-exercise. An ad libitum meal was served 60 min later, with subjective appetite measured throughout. Drinks were flavoured and matched for energy content and volume. The PRO drink provided 0.3 g/kg body mass protein. RESULTS Ad libitum energy intake (PRO 3742 ± 994 kJ; CHO 4172 ± 1132 kJ; P = 0.007) and mean eating rate (PRO 339 ± 102 kJ/min; CHO 405 ± 154 kJ/min; P = 0.009) were lower during PRO. The change in eating rate was associated with the change in energy intake (R = 0.661, P = 0.007). No interaction effects were observed for subjective measures of appetite. The PRO drink was perceived as creamier and thicker, and less pleasant, sweet and refreshing (P < 0.05). CONCLUSION These results suggest whey protein consumption after resistance exercise reduces subsequent energy intake, and this might be partially mediated by a reduced eating rate. Whilst this reduced energy intake is unlikely to impair hypertrophy, it may be of value in supporting an energy deficit for weight loss.