-
1.
Effects of home confinement on mental health and lifestyle behaviours during the COVID-19 outbreak: insights from the ECLB-COVID19 multicentre study.
Ammar, A, Trabelsi, K, Brach, M, Chtourou, H, Boukhris, O, Masmoudi, L, Bouaziz, B, Bentlage, E, How, D, Ahmed, M, et al
Biology of sport. 2021;38(1):9-21
-
-
-
Free full text
Plain language summary
Coronavirus disease 2019 (COVID-19) is an infectious disease caused by the respiratory syndrome coronavirus 2 (SARS-CoV-2). To curb the spread of the 2020 pandemic, social distancing, self-isolation and nationwide lockdown measures were put in place. These measures along with hygiene care are recognized as the most effective ways to curb the spread of disease. However; the weakening of social contacts can result in anxiety, frustration, panic attacks, loss or sudden increase of appetite, insomnia, depression, mood swings, delusions, fear, sleep disorders, and suicidal/domestic violence. The purpose of the study is to provide scientific data to help identify risk factors for the psychosocial strain during the COVID-19 outbreak. The study is an international cross-disciplinary online survey and was circulated in April 2020. 1047 replies were analysed from this preliminary phase. The results show a significant difference in all tested parameters and therefore reveal a large burden for mental wellbeing combined with a tendency towards an unhealthy lifestyle during, compared to before, the confinement enforced by the COVID-19 pandemic. These results highlight the importance for policy makers to consider strategies to promote wellbeing during future confinements.
Abstract
Although recognised as effective measures to curb the spread of the COVID-19 outbreak, social distancing and self-isolation have been suggested to generate a burden throughout the population. To provide scientific data to help identify risk factors for the psychosocial strain during the COVID-19 outbreak, an international cross-disciplinary online survey was circulated in April 2020. This report outlines the mental, emotional and behavioural consequences of COVID-19 home confinement. The ECLB-COVID19 electronic survey was designed by a steering group of multidisciplinary scientists, following a structured review of the literature. The survey was uploaded and shared on the Google online survey platform and was promoted by thirty-five research organizations from Europe, North Africa, Western Asia and the Americas. Questions were presented in a differential format with questions related to responses "before" and "during" the confinement period. 1047 replies (54% women) from Western Asia (36%), North Africa (40%), Europe (21%) and other continents (3%) were analysed. The COVID-19 home confinement evoked a negative effect on mental wellbeing and emotional status (P < 0.001; 0.43 ≤ d ≤ 0.65) with a greater proportion of individuals experiencing psychosocial and emotional disorders (+10% to +16.5%). These psychosocial tolls were associated with unhealthy lifestyle behaviours with a greater proportion of individuals experiencing (i) physical (+15.2%) and social (+71.2%) inactivity, (ii) poor sleep quality (+12.8%), (iii) unhealthy diet behaviours (+10%), and (iv) unemployment (6%). Conversely, participants demonstrated a greater use (+15%) of technology during the confinement period. These findings elucidate the risk of psychosocial strain during the COVID-19 home confinement period and provide a clear remit for the urgent implementation of technology-based intervention to foster an Active and Healthy Confinement Lifestyle AHCL).
-
2.
Vegetarian and Vegan Diet in Fibromyalgia: A Systematic Review.
Nadal-Nicolás, Y, Miralles-Amorós, L, Martínez-Olcina, M, Sánchez-Ortega, M, Mora, J, Martínez-Rodríguez, A
International journal of environmental research and public health. 2021;18(9)
-
-
-
Free full text
Plain language summary
Fibromyalgia (FM) is a chronic non-degenerative disease of unknown etiology without effective medical treatment that mostly affects women. The aim of this study was to evaluate the efficacy of mainly plant-based diets in patients with FM compared to omnivorous diets. A secondary aim was to examine the main effects of these diets on patients’ symptoms and the improvement in their quality of life. This study is a systemic review of six studies (n = 4 clinical trials and n = 2 observational cohort studies). The selected studies included 157 FM patients in both the intervention and control groups, and more than 117 were women. Results indicate that a mainly plant-based diet improves biochemical parameters and body inflammation; body weight, sleep quality, quality of life, pain at rest as well as other symptoms of FM and their impact on health. Authors conclude that even though their findings are promising further well-designed clinical trials are needed to consolidate these dietary recommendations in FM patient.
Abstract
Fibromyalgia (FM) is a chronic non-degenerative disease characterized by the presence of multiple symptoms such as chronic pain, which negatively influence the quality of life of sufferers, most of whom are women. Currently, there is no effective treatment to limit the impact of these symptoms. The aim of this research is to review the scientific evidence on the effect of following a vegetarian or vegan diet on fibromyalgia patients. A systematic review included the original articles that answered the research question. These articles were in 2021 in the PubMed, Web of Science and Scopus databases. The research used the PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines. No time restriction was applied, and grey literature was not included. The evaluation of the methodological quality of the articles was carried out using the following different scales: STROBE (strengthening the reporting of observational studies in epidemiology), PEDro (Physiotherapy Evidence Database), and MMAT (Mixed Methods Appraisal Tool) scales. A total of 88 studies were analyzed, of which 6 investigations were included in this systematic review (n = 4 clinical trials and n = 2 cohort studies). These investigations show significant improvements in biochemical parameters, quality of life, quality of sleep, pain at rest and general health status when following mainly plant-based dietary patterns. In conclusion, these findings are promising but interpretation of the findings is limited due to the methodological quality of the studies. Well-designed clinical trials are needed to consolidate these dietary recommendations in FM patients.
-
3.
A Systematic Review of the Association Between Vegan Diets and Risk of Cardiovascular Disease.
Kaiser, J, van Daalen, KR, Thayyil, A, Cocco, MTARR, Caputo, D, Oliver-Williams, C
The Journal of nutrition. 2021;151(6):1539-1552
-
-
-
Free full text
-
Plain language summary
Plant-based diets have increased in popularity due to concerns for the environment and animal welfare and due to perceived health benefits. The aim of this study was to assess the association between vegan diets and risks of primary, intermediate, and recurrent cardiovascular disease (CVD). This study is a systemic review of 7 epidemiological studies comprising over 73,000 participants, of whom at least 7661 were vegans. Results indicate that there was no significant evidence of an association between adherence to a vegan diet and risks of primary CVD or a coronary heart disease event. Authors conclude that further experimental evidence and research in large diverse cohorts is required in order to better understand the clinical relevance and public health implications of the vegan diet.
Abstract
BACKGROUND Plant-based diets are gaining attention globally due to their environmental benefits and perceived health-protective role. A vegan diet may have cardiovascular benefits; however, evidence remains conflicting and insufficiently assessed. OBJECTIVES We evaluated the utility of the vegan diet in cardiovascular disease (CVD) prevention. METHODS We conducted a systematic review of studies evaluating the association between vegan diets and cardiovascular outcomes. We searched 5 databases (Ovid MEDLINE, EMBASE, Web of Science, Scopus, and OpenGrey) through 31 October 2020. Four investigators independently screened the full texts for inclusion, assessed quality, and extracted data from published reports. RESULTS Out of the 5729 identified records, 7 were included, comprising over 73,000 participants, of whom at least 7661 were vegans. Three studies, with at least 73,426 individuals (including at least 7380 vegans), examined risks of primary cardiovascular events (total CVD, coronary heart disease, acute myocardial infarction, total stroke, hemorrhagic stroke, and ischemic stroke) in individuals who followed a vegan diet compared to those who did not. None of the studies reported a significantly increased or decreased risk of any cardiovascular outcome. One study suggested that vegans were at greater risk of ischemic stroke compared to individuals who consumed animal products (HR, 1.54; 95% CI, 0.95-2.48). Yet in another study, vegans showed lower common carotid artery intima-media thickness (0.56 ± 0.1 mm vs. 0.74 ± 0.1 mm in controls; P < 0.001), and in 3 studies of recurrent CVD events, vegans had 0-52% lower rates. Furthermore, endothelial function did not differ between vegans and nonvegans. Using the Grading of Recommendations Assessment, Development and Evaluation approach, evidence was deemed to be of low to very low strength/quality. CONCLUSIONS Among the Western populations studied, evidence weakly demonstrates associations between vegan diets and risk of CVDs, with the direction of associations varying with the specific CVD outcome tested. However, more high-quality research on this topic is needed. This study was registered at PROSPERO as CRD42019146835.
-
4.
Vegan diet in young children remodels metabolism and challenges the statuses of essential nutrients.
Hovinen, T, Korkalo, L, Freese, R, Skaffari, E, Isohanni, P, Niemi, M, Nevalainen, J, Gylling, H, Zamboni, N, Erkkola, M, et al
EMBO molecular medicine. 2021;13(2):e13492
-
-
-
Free full text
-
Plain language summary
As vegan diets gain popularity amongst families, there is little known about the impact of strict plant-based diets on metabolism and micronutrient status in children, apart from reduced average growth within the norm. This small study looked at 40 Finnish children from one day centre, and compared children following an omnivore or vegetarian diet to those raised on a vegan diet. The diets were analysed, and biomarkers and metabolites were measured. The metabolic profile and nutrient status of children who followed a vegan diet from birth were distinctively different to other diet patterns, including vegetarians. The authors suggest that little animal source foods are enough to shift the metabolism of children. Dietary analysis showed that vegan children had higher folate consumption and lower protein and saturated fats intake. Despite intake appearing adequate, serum markers for fat-soluble vitamins A and D were low. While the fatty acid ALA was higher compared to omnivores, DHA and overall cholesterol were decreased. The authors concluded that the bodies own cholesterol production does not seem to compensate for a lack of dietary cholesterol in this case and it remains to be established whether lower cholesterol in vegan children are negative to health. Furthermore, the circulating amino acids pool was decreased in vegan children, particularly branch chained amino acids. The most distinct difference, however, was seen in the variance of bile acid patterns. The physiological functions of bile acids go beyond digestion, yet the consequences of diverging bile acid profiles in children’s health are unknown. In conclusion, the data shows that a strict vegan diet affects the metabolism of healthy children, but much of the long-term impact on health is currently still unclear. This article highlights some of the differences, risks and uncertainties that come with raising young children on a strictly vegan diet.
Abstract
Vegan diets are gaining popularity, also in families with young children. However, the effects of strict plant-based diets on metabolism and micronutrient status of children are unknown. We recruited 40 Finnish children with a median age 3.5 years-vegans, vegetarians, or omnivores from same daycare centers-for a cross-sectional study. They enjoyed nutritionist-planned vegan or omnivore meals in daycare, and the full diets were analyzed with questionnaires and food records. Detailed analysis of serum metabolomics and biomarkers indicated vitamin A insufficiency and border-line sufficient vitamin D in all vegan participants. Their serum total, HDL and LDL cholesterol, essential amino acid, and docosahexaenoic n-3 fatty acid (DHA) levels were markedly low and primary bile acid biosynthesis, and phospholipid balance was distinct from omnivores. Possible combination of low vitamin A and DHA status raise concern for their visual health. Our evidence indicates that (i) vitamin A and D status of vegan children requires special attention; (ii) dietary recommendations for children cannot be extrapolated from adult vegan studies; and (iii) longitudinal studies on infant-onset vegan diets are warranted.
-
5.
Evolution of the Human Diet and Its Impact on Gut Microbiota, Immune Responses, and Brain Health.
González Olmo, BM, Butler, MJ, Barrientos, RM
Nutrients. 2021;13(1)
-
-
-
Free full text
Plain language summary
One explanation for the increased prevalence in chronic disease and mental illness is from the evolutionary perspective. This suggests the rapid shift in diet towards processed foods in the past 200 years has not allowed for sufficient adaptation of the gut microbiome. The gut microbiome plays an important role in the digestive, immune and nervous systems via the gut-brain axis, and may be a key factor in modulating inflammation and disease. The aim of this review is to discuss how what we eat affects the immune system and impacts our brain health. The literature currently shows significant associations between the Western diet and its impact on the health of the gut microbiome and the brain. Increased intake of saturated fats, refined carbohydrates and sugar, coupled with a reduction in fiber, negatively impacts the digestive system and elicits an immune response. This response can lead to neuroinflammation, which is now found to be associated with deficits in learning and memory, as well as increased rates of neurodegenerative disease and depression. Based on the existing literature, the authors conclude the human gut microbiome has not had sufficient time to adapt to many modern foods, thus leading to inflammation and disease. The authors recommend that a diet composed of natural whole foods with minimal processing can help prevent and alleviate some of the burden caused by chronic disease, and suggest future studies focus on improving techniques to evaluate neuroinflammation in humans.
Abstract
The relatively rapid shift from consuming preagricultural wild foods for thousands of years, to consuming postindustrial semi-processed and ultra-processed foods endemic of the Western world less than 200 years ago did not allow for evolutionary adaptation of the commensal microbial species that inhabit the human gastrointestinal (GI) tract, and this has significantly impacted gut health. The human gut microbiota, the diverse and dynamic population of microbes, has been demonstrated to have extensive and important interactions with the digestive, immune, and nervous systems. Western diet-induced dysbiosis of the gut microbiota has been shown to negatively impact human digestive physiology, to have pathogenic effects on the immune system, and, in turn, cause exaggerated neuroinflammation. Given the tremendous amount of evidence linking neuroinflammation with neural dysfunction, it is no surprise that the Western diet has been implicated in the development of many diseases and disorders of the brain, including memory impairments, neurodegenerative disorders, and depression. In this review, we discuss each of these concepts to understand how what we eat can lead to cognitive and psychiatric diseases.
-
6.
Augmenting Clinical Interventions in Psychiatric Disorders: Systematic Review and Update on Nutrition.
Offor, SJ, Orish, CN, Frazzoli, C, Orisakwe, OE
Frontiers in psychiatry. 2021;12:565583
-
-
-
Free full text
Plain language summary
Mental disorders are widespread and impact significantly on health. “Nutritional psychiatry” pivots on the impact of nutrition (food) on the state of mind and mood. The aim of this study was to justify the inclusion and recognition of nutrition in the management of psychiatric illnesses. This study is a systemic review which included 97 studies. The literature shows that several foods and food compounds modulate biomarkers and molecular mechanisms involved in the aetiogenesis [the origin and development of a pathological condition] of several mental disorders. Furthermore, the evidence-based approach warrants the inclusion and co-recognition of nutrition in the management of psychiatric illnesses. Authors conclude that there is a need to advocate for policies aimed at bridging the knowledge gap and encourage the utilization and integration of nutrition in addition to contemporary therapies in clinical settings.
Abstract
There is a strong relationship between a healthy diet and mental well-being. Several foods and food compounds are known to modulate biomarkers and molecular mechanisms involved in the aetiogenesis of several mental disorders, and this can be useful in containing the disease progression, including its prophylaxis. This is an updated systematic review of the literature to justify the inclusion and recognition of nutrition in the management of psychiatric illnesses. Such foods and their compounds include dietary flavanols from fruits and vegetables, notable antioxidant and anti-inflammatory agents, probiotics (fermented foods) known to protect good gut bacteria, foods rich in polyunsaturated fatty acids (e.g., Omega-3), and avoiding diets high in saturated fats and refined sugars among others. While the exact mechanism(s) of mitigation of many nutritional interventions are yet to be fully understood, the evidence-based approach warrants the inclusion and co-recognition of nutrition in the management of psychiatric illnesses. For the greater public health benefit, there is a need for policy advocacy aimed at bridging the knowledge gap and encouraging the integration of nutritional intervention with contemporary therapies in clinical settings, as deficiencies of certain nutrients make therapy difficult even with appropriate medication.
-
7.
Food and mood: how do diet and nutrition affect mental wellbeing?
The British Medical Journal (BMJ) is a global healthcare knowledge provider with a vision for a healthier world. It shares knowledge and expertise to improve healthcare outcomes. They publish more than 70 medical and allied science journals.
2021
Abstract
This article provides the reader with an extensive analysis of the connection between poor nutrition and low mood, and offers insightful cues in regards to the impact of healthier diets on mental health. The Mediterranean diet, with its high consumption of vegetables, fruits, nuts, and legumes; moderate consumption of poultry, eggs, and dairy products; and only occasional consumption of red meat—is associated with a reduced risk of depression. Moreover, the relationship between food and mood can be altered by the effect that specific foods have on blood sugar levels, immune activation, and the gut microbiome. Inflammatory markers are elevated in people that follow diets which are high in calories and saturated fats and this seems to appear as one of the mechanisms through which the Western diet can dramatically impact brain health.
-
8.
An updated systematic review and meta-analysis on adherence to mediterranean diet and risk of cancer.
Morze, J, Danielewicz, A, Przybyłowicz, K, Zeng, H, Hoffmann, G, Schwingshackl, L
European journal of nutrition. 2021;60(3):1561-1586
-
-
-
Free full text
-
Plain language summary
The development of cancer is associated with a number of risk factors, including smoking, obesity, sedentary lifestyles, alcohol consumption, infections, pollution, and dietary imbalances. Based on previous research, optimal consumption of fruits, vegetables, and whole grains, along with reduced consumption of red and processed meat, reduces cancer risk. According to this systematic review and meta-analysis, adherence to the Mediterranean diet is associated with lower cancer mortality and site-specific cancer development. A Mediterranean diet includes fruits, vegetables, nuts, legumes, fish, whole grains, extra virgin olive oil, and low amounts of red meat, processed meat, egg, and dairy, along with moderate amounts of red wine. According to this systematic review and meta-analysis, adherence to the Mediterranean diet reduces the risk of cancer mortality and the risk of developing cancers specific to the site, such as colorectal cancer, bladder cancer, gastric cancer, and lung cancer. Among the components of the Mediterranean diet, fruits, vegetables, and whole grains have been shown to reduce cancer risk. Bioactive substances found in Mediterranean diet components require additional robust studies to evaluate their benefits. A healthcare professional can use the results of this study to make clinical decisions and recommend therapeutic interventions to cancer patients.
Abstract
PURPOSE The aim of current systematic review was to update the body of evidence on associations between adherence to the Mediterranean diet (MedDiet) and risk of cancer mortality, site-specific cancer in the general population; all-cause, and cancer mortality as well as cancer reoccurrence among cancer survivors. METHODS A literature search for randomized controlled trials (RCTs), case-control and cohort studies published up to April 2020 was performed using PubMed and Scopus. Study-specific risk estimates for the highest versus lowest adherence to the MedDiet category were pooled using random-effects meta-analyses. Certainty of evidence from cohort studies and RCTs was evaluated using the NutriGrade scoring system. RESULTS The updated search revealed 44 studies not identified in the previous review. Altogether, 117 studies including 3,202,496 participants were enclosed for meta-analysis. The highest adherence to MedDiet was inversely associated with cancer mortality (RRcohort: 0.87, 95% CI 0.82, 0.92; N = 18 studies), all-cause mortality among cancer survivors (RRcohort: 0.75, 95% CI 0.66, 0.86; N = 8), breast (RRobservational: 0.94, 95% CI 0.90, 0.97; N = 23), colorectal (RRobservational: 0.83, 95% CI 0.76, 0.90; N = 17), head and neck (RRobservational: 0.56, 95% CI 0.44, 0.72; N = 9), respiratory (RRcohort: 0.84, 95% CI 0.76, 0.94; N = 5), gastric (RRobservational: 0.70, 95% CI 0.61, 0.80; N = 7), bladder (RRobservational: 0.87, 95% CI 0.76, 0.98; N = 4), and liver cancer (RRobservational: 0.64, 95% CI 0.54, 0.75; N = 4). Adhering to MedDiet did not modify risk of blood, esophageal, pancreatic and prostate cancer risk. CONCLUSION In conclusion, our results suggest that highest adherence to the MedDiet was related to lower risk of cancer mortality in the general population, and all-cause mortality among cancer survivors as well as colorectal, head and neck, respiratory, gastric, liver and bladder cancer risks. Moderate certainty of evidence from cohort studies suggest an inverse association for cancer mortality and colorectal cancer, but most of the comparisons were rated as low or very low certainty of evidence.
-
9.
The Association between Diet and Hepatocellular Carcinoma: A Systematic Review.
George, ES, Sood, S, Broughton, A, Cogan, G, Hickey, M, Chan, WS, Sudan, S, Nicoll, AJ
Nutrients. 2021;13(1)
-
-
-
Free full text
Plain language summary
Liver cancer is the sixth most common cause of cancer death in Australia. Hepatocellular carcinoma (HCC) is the most prevalent type of primary liver cancer. Obesity and diabetes are known risk factors for HCC development and so is the presence of liver cirrhosis, which can occur in hepatitis infections, dietary aflatoxins produced by certain moulds, excessive alcohol intake, tobacco smoking, and metabolic associated fatty liver disease. Emerging evidence recognises diet as a potential lifestyle-related risk factor in the development of HCC. This systematic review sought to determine whether there is an association between diet and the development of HCC by analysing 30 observational studies. Reduced risk in HCC development was seen in people who followed either a Mediterranean, Urban Prudent or Traditional Cantonese dietary pattern diet or ate according to the Alternative Healthy Eating Index-2010. Similarly, the intake of vegetables, whole grains, fish, poultry, coffee, plant-based compounds like isoflavones, macronutrients such as monounsaturated fats and micronutrients including vitamin E, vitamin B9, β-carotene, manganese and potassium were associated with reduced risk. Whereby sugar-sweetened beverages and processed red meat consumption appeared to increase HCC risk. This review found no particular impact concerning the DASH diet, nuts and fruit intake. Further discussed are also some of the potential mechanisms that some dairy products and omega-6 have on cancer and HCC risk. In conclusion, certain dietary patterns and diet components influence the risk of HCC development, thus affirming a dietary role in disease development and prevention. However, the impact on diet in high-risk individuals or those who already have HBV or cirrhosis remains to be studied further.
Abstract
Globally, liver cancer is the sixth most common cause of cancer mortality, with hepatocellular carcinoma (HCC) being the most common type of primary liver cancer. Emerging evidence states that diet is recognised as a potential lifestyle-related risk factor for the development of HCC. The aim of this systematic review is to determine whether there is an association between diet and the development of HCC. Using the PRISMA guidelines, three databases (MEDLINE Complete, CINAHL and Embase) were systematically searched, and studies published until July 2020 were included. Thirty observational studies were selected. The protocol was registered with PROSPERO (CRD42019135240). Higher adherence to the Mediterranean dietary pattern, Alternative Healthy Eating Index-2010, the Urban Prudent Dietary Pattern, the Traditional Cantonese Dietary Pattern, intake of vegetables, wholegrains, fish, poultry, coffee, macronutrients such as monounsaturated fats and micronutrients such as vitamin E, vitamin B9, β-carotene, manganese and potassium were associated with a reduced risk of HCC. The results suggest a potential role of diet in the development of HCC. Further quantitative research needs to be undertaken within a range of populations to investigate diet and the relationship with HCC risk.
-
10.
Comparing Acute, High Dietary Protein and Carbohydrate Intake on Transcriptional Biomarkers, Fuel Utilisation and Exercise Performance in Trained Male Runners.
Furber, M, Pyle, S, Roberts, M, Roberts, J
Nutrients. 2021;13(12)
-
-
-
Free full text
Plain language summary
Dietary modification to improve exercise endurance has become a popular strategy. The reduction of carbohydrates to enhance adaptations due to training has been shown on a cellular level. In low carbohydrate diets, fat is the usual substitute, however long-term adherence to this is often difficult. Using protein instead of fat may be an alternative, but there is little research on this. This study aimed to investigate the impact of a short-term high-protein, reduced carbohydrate diet compared to a high-carbohydrate diet in combination with endurance running on exercise performance and cellular adaptations. The results showed that any cellular adaptations were due to fuel availability, rather than the fuel type and that a high protein diet compromised high intensity exercise performance. It was concluded that a high-protein, low-carbohydrate diet in combination with endurance training is of no benefit to endurance running performance. This study could be used by healthcare professionals to recommend that athletes and especially runners who wish to improve endurance do not switch to a high-protein, low carbohydrate diet and that other dietary modifications are investigated.
Abstract
Manipulating dietary macronutrient intake may modulate adaptive responses to exercise, and improve endurance performance. However, there is controversy as to the impact of short-term dietary modification on athletic performance. In a parallel-groups, repeated measures study, 16 trained endurance runners (maximal oxygen uptake (V˙O2max): 64.2 ± 5.6 mL·kg-1·min-1) were randomly assigned to, and provided with, either a high-protein, reduced-carbohydrate (PRO) or a high-carbohydrate (CHO) isocaloric-matched diet. Participants maintained their training load over 21-consecutive days with dietary intake consisting of 7-days habitual intake (T1), 7-days intervention diet (T2) and 7-days return to habitual intake (T3). Following each 7-day dietary period (T1-T3), a micro-muscle biopsy was taken for assessment of gene expression, before participants underwent laboratory assessment of a 10 km treadmill run at 75% V˙O2max, followed by a 95% V˙O2max time to exhaustion (TTE) trial. The PRO diet resulted in a modest change (1.37-fold increase, p = 0.016) in AMPK expression, coupled with a significant increase in fat oxidation (0.29 ± 0.05 to 0.59 ± 0.05 g·min-1, p < 0.0001). However, a significant reduction of 23.3% (p = 0.0003) in TTE post intervention was observed; this reverted back to pre levels following a return to the habitual diet. In the CHO group, whilst no change in sub-maximal fuel utilisation occurred at T2, a significant 6.5% increase in TTE performance (p = 0.05), and a modest, but significant, increase in AMPK (p = 0.042) and PPAR (p = 0.029) mRNA expression compared to T1 were observed; with AMPK (p = 0.011) and PPAR (p = 0.044) remaining significantly elevated at T3. In conclusion, a 7-day isocaloric high protein diet significantly compromised high intensity exercise performance in trained runners with no real benefit on gene markers of training adaptation. A significant increase in fat oxidation during submaximal exercise was observed post PRO intervention, but this returned to pre levels once the habitual diet was re-introduced, suggesting that the response was driven via fuel availability rather than cellular adaptation. A short-term high protein, low carbohydrate diet in combination with endurance training is not preferential for endurance running performance.