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Changes in fasting patterns during Ramadan, and associated clinical outcomes in adults with type 2 diabetes: A narrative review of epidemiological studies over the last 20 years.
Hassanein, MM, Hanif, W, Malek, R, Jabbar, A
Diabetes research and clinical practice. 2021;:108584
Abstract
Although religious guidance exempts some Muslims with type 2 diabetes from fasting during Ramadan, many choose to fast. The associated risks for fasting adults with diabetes includes hypoglycemia, hyperglycemia, ketoacidosis, dehydration, and thrombosis. Thus, it is important that healthcare professionals support individuals who choose to fast to minimize risks. We reviewed three epidemiologic studies to understand how fasting patterns during Ramadan and associated clinical outcomes in adults with type 2 diabetes have evolved over two decades (2000-2020). Over a period of time people with diabetes choosing to fast during Ramadan are displaying increasingly complex profiles in terms of their diabetes, with increased disease duration, greater body mass index, and elevated pre-Ramadan mean glycated hemoglobin levels. Despite this, in the most recent study, >85% of adults with type 2 diabetes still chose to fast. Increased risk of hypoglycemia remains a major concern despite some improvements over time, which could be attributable to enhanced education programs, and changes in treatment type and/or dose prior to and/or during Ramadan. Our review highlights the evolution in fasting patterns over two decades and serves as an update for healthcare professionals to provide appropriate guidance to ensure that Ramadan fasting is safe and rewarding.
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Energy and caloric restriction, and fasting and cancer: a narrative review.
Ibrahim, EM, Al-Foheidi, MH, Al-Mansour, MM
Supportive care in cancer : official journal of the Multinational Association of Supportive Care in Cancer. 2021;(5):2299-2304
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Dietary interventions have a significant impact on body metabolism. The sensitivity of cancer cells to nutrient and energy deficiency is an evolving characteristic of cancer biology. Preclinical studies provided robust evidence that energy and caloric restrictions could hinder both cancer growth and progression, besides enhancing the efficacy of chemotherapy and radiation therapy. Moreover, several, albeit low-powered, clinical trials have demonstrated clinical benefits in cancer patients. Future research will inform and firmly establish the potential efficacy and safety of these dietary interventions. Here, we review the current evidence and ongoing research investigating the relationship between various dietary restriction approaches and cancer outcomes.
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Intermittent Fasting and Obesity-Related Health Outcomes: An Umbrella Review of Meta-analyses of Randomized Clinical Trials.
Patikorn, C, Roubal, K, Veettil, SK, Chandran, V, Pham, T, Lee, YY, Giovannucci, EL, Varady, KA, Chaiyakunapruk, N
JAMA network open. 2021;(12):e2139558
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IMPORTANCE Several meta-analyses of randomized clinical trials (RCTs) have demonstrated the many health benefits of intermittent fasting (IF). However, there has been little synthesis of the strength and quality of this evidence in aggregate to date. OBJECTIVE To grade the evidence from published meta-analyses of RCTs that assessed the associations of IF (zero-calorie alternate-day fasting, modified alternate-day fasting, the 5:2 diet, and time-restricted eating) with obesity-related health outcomes. EVIDENCE REVIEW PubMed, Embase, and Cochrane database of systematic reviews were searched from database inception to January 12, 2021. Data analysis was conducted from April 2021 through July 2021. Meta-analyses of RCTs investigating effects of IF in adults were included. The effect sizes of IF were recalculated using a random-effects model. We assessed the quality of evidence per association by applying the GRADE criteria (Grading of Recommendations, Assessment, Development, and Evaluations) as high, moderate, low, and very low. FINDINGS A total of 11 meta-analyses comprising 130 RCTs (median [IQR] sample size, 38 [24-69] participants; median [IQR] follow-up period, 3 [2-5] months) were included describing 104 unique associations of different types of IF with obesity-related health outcomes (median [IQR] studies per association, 4 [3-5]). There were 28 statistically significant associations (27%) that demonstrated the beneficial outcomes for body mass index, body weight, fat mass, low-density lipoprotein cholesterol, total cholesterol, triglycerides, fasting plasma glucose, fasting insulin, homeostatic model assessment of insulin resistance, and blood pressure. IF was found to be associated with reduced fat-free mass. One significant association (1%) supported by high-quality evidence was modified alternate-day fasting for 1 to 2 months, which was associated with moderate reduction in body mass index in healthy adults and adults with overweight, obesity, or nonalcoholic fatty liver disease compared with regular diet. Six associations (6%) were supported by moderate quality evidence. The remaining associations found to be significant were supported by very low (75 associations [72%]) to low (22 associations [21%]) quality evidence. CONCLUSIONS AND RELEVANCE In this umbrella review, we found beneficial associations of IF with anthropometric and cardiometabolic outcomes supported by moderate to high quality of evidence, which supports the role of IF, especially modified alternate-day fasting, as a weight loss approach for adults with overweight or obesity. More clinical trials with long-term follow-up are needed to investigate the effects of IF on clinical outcomes such as cardiovascular events and mortality.
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Fasting and Exercise in Oncology: Potential Synergism of Combined Interventions.
Wilson, RL, Kang, DW, Christopher, CN, Crane, TE, Dieli-Conwright, CM
Nutrients. 2021;(10)
Abstract
Nutrition and exercise interventions are strongly recommended for most cancer patients; however, much debate exists about the best prescription. Combining fasting with exercise is relatively untouched within the oncology setting. Separately, fasting has demonstrated reductions in chemotherapy-related side effects and improved treatment tolerability and effectiveness. Emerging evidence suggests fasting may have a protective effect on healthy cells allowing chemotherapy to exclusively target cancer cells. Exercise is commonly recommended and attenuates treatment- and cancer-related adverse changes to body composition, quality of life, and physical function. Given their independent benefits, in combination, fasting and exercise may induce synergistic effects and further improve cancer-related outcomes. In this narrative review, we provide a critical appraisal of the current evidence of fasting and exercise as independent interventions in the cancer population and discuss the potential benefits and mechanisms of combined fasting and exercise on cardiometabolic, body composition, patient-reported outcomes, and cancer-related outcomes. Our findings suggest that within the non-cancer population combined fasting and exercise is a viable strategy to improve health-related outcomes, however, its safety and efficacy in the oncology setting remain unknown. Therefore, we also provide a discussion on potential safety issues and considerations for future research in the growing cancer population.
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Eat, Train, Sleep-Retreat? Hormonal Interactions of Intermittent Fasting, Exercise and Circadian Rhythm.
Haupt, S, Eckstein, ML, Wolf, A, Zimmer, RT, Wachsmuth, NB, Moser, O
Biomolecules. 2021;(4)
Abstract
The circadian rhythmicity of endogenous metabolic and hormonal processes is controlled by a complex system of central and peripheral pacemakers, influenced by exogenous factors like light/dark-cycles, nutrition and exercise timing. There is evidence that alterations in this system may be involved in the pathogenesis of metabolic diseases. It has been shown that disruptions to normal diurnal rhythms lead to drastic changes in circadian processes, as often seen in modern society due to excessive exposure to unnatural light sources. Out of that, research has focused on time-restricted feeding and exercise, as both seem to be able to reset disruptions in circadian pacemakers. Based on these results and personal physical goals, optimal time periods for food intake and exercise have been identified. This review shows that appropriate nutrition and exercise timing are powerful tools to support, rather than not disturb, the circadian rhythm and potentially contribute to the prevention of metabolic diseases. Nevertheless, both lifestyle interventions are unable to address the real issue: the misalignment of our biological with our social time.
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Intermittent Fasting and Metabolic Health: From Religious Fast to Time-Restricted Feeding.
Hoddy, KK, Marlatt, KL, Çetinkaya, H, Ravussin, E
Obesity (Silver Spring, Md.). 2020;(Suppl 1):S29-S37
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Over the past 10 to 15 years, intermittent fasting has emerged as an unconventional approach to reduce body weight and improve metabolic health beyond simple calorie restriction. In this review, we summarize findings related to Ramadan and Sunnah fasting. We then discuss the role of caloric restriction not only as an intervention for weight control, but importantly, as a strategy for healthy aging and longevity. Finally, we review the four most common intermittent fasting (IF) strategies used to date for weight management and to improve cardiometabolic health. Weight loss is common after IF but does not appear to be different than daily caloric restriction when compared directly. IF may also provide additional cardiometabolic benefit, such as insulin sensitization, that is independent from weight loss. While no specific fasting regimen stands out as superior at this time, there is indeed heterogeneity in responses to these different IF diets. This suggests that one dietary regimen may not be ideally suited for every individual. Future studies should consider strategies for tailoring dietary prescriptions, including IF, based on advanced phenotyping and genotyping prior to diet initiation.
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Effects of Ramadan Observance on Dietary Intake and Body Composition of Adolescent Athletes: Systematic Review and Meta-Analysis.
Trabelsi, K, Ammar, A, Boukhris, O, Glenn, JM, Bott, N, Stannard, SR, Engel, FA, Sperlich, B, Garbarino, S, Bragazzi, NL, et al
Nutrients. 2020;(6)
Abstract
To evaluate the effects of Ramadan observance on dietary intake, body mass and body composition of adolescent athletes (design: systematic review and meta-analysis; data sources: PubMed and Web of Science; eligibility criteria for selecting studies: single-group, pre-post, with or without control-group studies, conducted in athletes aged <19 years, training at least 3 times/week, and published in any language before February 12th, 2020). Studies assessing body mass and/or body composition and/or dietary intake were deemed eligible. The methodological quality was assessed using 'QualSyst'. Of the twelve selected articles evaluating body mass and/or body composition, one was of strong quality and eleven were rated as moderate. Ten articles evaluated dietary intake; four were rated as strong and the remaining moderate in quality. Continuation of training during Ramadan did not change body mass from before to the first week (trivial effect size (ES) = -0.011, p = 0.899) or from before to the fourth week of Ramadan (trivial ES = 0.069, p = 0.277). Additionally, Ramadan observance did not change body fat content from before to the first week (trivial ES = -0.005, p = 0.947) and from before to the fourth week of Ramadan (trivial ES = -0.057, p = 0.947). Lean body mass remained unchanged from before to the fourth week of Ramadan (trivial ES = -0.025, p = 0.876). Dietary data showed the intake of energy (small ES = -0.272, p = 0.182), fat (trivial ES = 0.044, p = 0.842), protein (trivial ES = 0.069, p = 0.720), carbohydrate (trivial ES = 0.075, p = 0.606) and water (trivial ES = -0.115, p = 0.624) remained essentially unchanged during as compared to before Ramadan. Continued training of adolescent athletes at least three times/week during Ramadan observance has no effect on body mass, body composition or dietary intake.
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Intermittent fasting as a nutrition approach against obesity and metabolic disease.
Zhu, S, Surampudi, P, Rosharavan, B, Chondronikola, M
Current opinion in clinical nutrition and metabolic care. 2020;(6):387-394
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PURPOSE OF REVIEW Intermittent fasting has been proposed as a potential nutrition approach against obesity and metabolic disease. Although data from studies in rodents convincingly support the antiobesity and cardiometabolic benefits of intermittent fasting, its effects in human health are still debatable. RECENT FINDINGS Recent studies have examined the effect of two intermittent fasting approaches, that is, alternate day fasting (ADF) and time-restricted eating (TRE), on weight loss and cardiometabolic risk factors. ADF seems to be an equally effective weight loss approach to caloric restriction, but adherence to ADF is more challenging. ADF improves cardiometabolic risk factors, whereas it may have superior metabolic benefits compared to caloric restriction in people with insulin resistance. TRE with ad libitum food intake is well tolerated and induces 2-4% weight loss in approximatively 3 months. Additionally, TRE may have metabolic benefits particularly in people with metabolically abnormal obesity even without weight loss. SUMMARY Intermittent fasting is a promising nutritional approach against obesity and its related metabolic diseases. Further research is needed to: i) establish the long-term effectiveness of TRE in weight loss and metabolic health, ii) improve the long-term adherence to ADF and investigate its weight loss independent effects in metabolic health, and iii) determine the mechanisms underlying the potential cardiometabolic benefits of intermittent fasting in humans.
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Effects of Time-Restricted Feeding during Ramadan on Dietary Intake, Body Composition and Metabolic Outcomes.
Osman, F, Haldar, S, Henry, CJ
Nutrients. 2020;(8)
Abstract
Ramadan fasting is a form of time-restricted feeding which combines a fast and feast period daily for a duration of one month every year. During Ramadan, Muslims abstain from food and drink consumption from dawn till sunset and this change in the meal schedule and frequency results in significant changes to the composition of the diet, such as energy and nutrient intake. These changes in dietary habits and their corresponding effects on cardiometabolic disease risk are compiled in this review. Ramadan fasting shows limited benefits to body composition via reductions in body mass in both healthy and obese individuals, although the results are often found to be transient and heterogeneous. There is, however, a more consistent improvement in blood lipid profile during Ramadan fasting, which often lasts beyond the Ramadan period. The results for glucose homeostasis, on the contrary, are more conflicting and inconclusive. The heterogeneity in the findings from the various studies can be generally attributed to cultural variations in dietary habits, differences in the duration of fasting due to seasonal/climatic differences at various geographical locations, age, gender and socioeconomic status, as well as other health and lifestyle factors of the various study populations.
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Claims of anomalously long fasting: An assessment of the evidence from investigated cases.
Mast, MH
Explore (New York, N.Y.). 2020;(5):287-296
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BACKGROUND Throughout history and to the present day, there have been reports of people claiming inedia, i.e., an anomalous long-term abstinence from food or from food and fluid. Some were isolated and monitored and their abstinences confirmed. This raises the question of whether there may be an anomaly with wide implications that science has overlooked. On the other hand, there have been cases of exposed fraud. The reports on the studies are scattered and it can be difficult to judge their rigor and the strength and implications of their evidence. A critical evaluation seems useful. OBJECTIVES The objectives were to obtain an overview of investigated cases of claimed inedia, to assess the anomaly of the claims and study results, to assess the quality of the studies, and to identify deception methods to inform future safeguards. METHOD I developed criteria for differentiating normal from anomalous nutrition and fasting and for assessing the quality of inedia studies. Studies found through a systematic search were then assessed and the features of cases of fraud extracted. RESULTS 47 eligible investigations of 38 claimants were found. Out of the 38 cases, results were assessed as (seemingly) anomalous in 11, with nine cases of monitored food and fluid deprivation ranging from 14 to 68 days (median 28 days), and two cases of food deprivation for 365 and 411 days. In 17 cases, anomaly was assessed as not confirmed due to issues with study design or reporting. Fraud was established in 10 cases. Deception methods were creative. Post-1900 studies were also assessed for quality. Quality was not considered adequate in any. CONCLUSIONS I consider the evidential status of inedia unconfirmed as no assessed study had both anomalous findings and impeccable quality. However, quality was often downgraded due to reporting issues and it cannot be concluded in reverse that all claimants with anomalous results were able to deceive the investigators. The results of many studies are curious and demand further research. The conducted analysis provides guidance for improving rigor and transparency in future studies.