Time restricted eating...Aligning food timing with circadian rhythms

 If you needed more motivation to start a time restricted eating program...here you go. Another great article from the Institute of Functional Medicine...

Chrononutrition: Food Timing, Circadian Fasting, and Resetting the Body’s Internal Clock

Circadian cycles are part of the body’s internal clock, and disruption to these biological rhythms may result in adverse health outcomes. Aligning meal timing with the body’s circadian cycle for optimal glucose and insulin responsiveness may be effective for improving metabolic health. In the field of chrononutrition, time-restricted feeding has been prominent in research, studied for its benefits on metabolic health and as a means for realigning and supporting the body’s internal clock. How do circadian considerations potentially benefit personalized health interventions for chronic disease treatment or prevention? Timing influences human physiology. Circadian cycles are a property of the body’s internal clock, and disruption to these biological rhythms may result in adverse health outcomes. The field of chronobiology is dynamic and continues to elucidate the associations between circadian rhythms and health implications, from neurodegenerative risks to metabolic dysfunctions.1,2 Chrononutrition is the focused study of the relationship between food, metabolism, meal timing, and the circadian system. Is there metabolic benefit when aligning lifestyle behaviors such as food timing with the body’s internal clock? How do circadian considerations influence personalized health interventions for chronic disease prevention or treatment? Aligning Food Timing With Circadian Rhythms Most cells and tissues of the body show molecular clock activity and express cellular clock genes that contribute to tissue and system function. In metabolic processes, circadian-related components modulate the activation and expression of hormones, enzymes, and signaling pathways.3,4 Aligning meal timing with the body’s circadian cycle for optimal glucose and insulin responsiveness, as well as with hormones such as cortisol and leptin that are also affected by circadian oscillations,3 may be effective for improving metabolic health. A 2023 meta-analysis of nine RCTs (n=485 total participants) compared higher energy consumption earlier in the day with higher consumption later in the day on weight loss and metabolic parameters.5 Researchers reported a significantly greater weight loss in groups with higher energy intakes earlier compared to groups with high energy intake later in the day. In addition, significantly greater reductions in LDL cholesterol, fasting glucose, and insulin resistance (measured by HOMA-IR) were reported in groups with earlier energy intakes compared with later intakes.5 Both glucose tolerance and insulin sensitivity have been shown to be lower in the evening than in the morning,6which may contribute to an increased risk of metabolic dysfunctions for those who habitually eat meals during the evening hours. A 2020 meta-analysis (n=10 acute postprandial studies) investigated whether acute glucose and insulin responses after night-time meals (8 pm–4 am) differed from the responses after day-time meals (7 am–4 pm) in healthy adults.7 Results indicated that after an identical meal, the postprandial glucose and insulin responses were both significantly lower in the day compared to the night.7 Interestingly, specific to carbohydrate intake, a 2022 systematic review of eight randomized clinical trials (n=116 healthy adults) indicated that consumption of carbohydrates at night also led to higher postprandial glycemic values than morning consumption; however, no significant difference between morning and night carbohydrate consumption was found for postprandial insulin values.8 TIME-RESTRICTED FEEDING & CIRCADIAN REALIGNMENT As the field of chrononutrition continues to expand and develop, time-restricted feeding (TRF) has been prominent in research, studied for its benefits on metabolic health and as a means for realigning and supporting the body’s circadian clock.9,10 As a form of circadian fasting, TRF is a dietary pattern that optimizes circadian elements by consuming food and beverage within a shortened window of time during the day, extending a person’s nightly fast to 12 hours or more. A 2022 systematic review of 22 TRF-related randomized controlled trials suggested that among adults with overweight/obesity, TRF may lead to improved insulin resistance and glycemic responsiveness throughout the day.11 Of note, most of the reviewed studies assessed the effects of a 16-hour fast/8-hour feeding regimen (day-time feeding window variable), with only one included study comparing the early TRF (eating between 6 am and 3 pm) with the mid-day TRF (eating between 11 am and 8 pm).11 Synchronizing lifestyle habits such as food timing with circadian biological rhythms has been studied in a range of health areas, including the management of non-alcoholic fatty liver disease,12,13 the reduction of blood pressure,14inflammation,15 reduced cognitive decline,16 and cancer risk.17 Evaluating the feasibility of this therapeutic nutritional approach continues to evolve. A recent pilot study tested the feasibility of implementing TRF in adults with overweight and obesity through a smartphone intervention.18 Fifty participants with a normal eating duration of 14 hours or more were enrolled. After the 90-day TRF trial, the average adherence to logging meal activities and to reducing eating windows was 64% and 47% respectively.18 Of note, 16 of the TRF participants reduced their eating window from an average of 16 hours to approximately 12 hours. In addition, decreases in body weight, waist circumference, and systolic blood pressure were reported.18 Chronotype & Personalized Nutrition It is important to note that some patients may not be suitable candidates for therapeutic fasting treatments due to preexisting conditions. However, for some patients, TRF interventions that optimize circadian elements by encouraging energy intake earlier in the day and increasing the fasting window have the potential to improve metabolic outcomes. As research develops, determining the optimal time period for TRF interventions (early TRF versus mid-day TRF) may be clarified. Ultimately, ideal eating times and habits could be associated with a patient’s chronotype. Genetic variations in clock genes contribute to varied circadian inclinations among individuals and may impact best sleep and meal schedules for any given person. Specific chronotypes, for example, an “early-bird” or “night-owl,” describes not only at what time a person is naturally inclined to sleep and to be awake but may also influence appetite and physical activity.19,20 Studies continue to investigate the impact of chronotype on disease development,21 and chrononutrition trials are beginning to explore chronotype influences on interventions for improved metabolic health.22 As part of a personalized, lifestyle-based approach, nutritional therapies tailored to the individual patient are crucial for effectiveness and sustainability. Circadian rhythms are just one component to consider when creating and implementing dietary interventions. A variety of factors such as potential underlying nutrient deficiencies, presentation of disease symptoms, food sensitivities, accessibility, and personal preferences may all shape personalized treatments. IFM’s suite of therapeutic food plans are all available for modification based on an individual’s health needs. Learn more about food plan personalization within the IFM framework and creating effective and sustainable nutrition-based strategies to promote health through the online course Therapeutic Food Plans: A Component of Personalized Nutrition. Source: <https://www.ifm.org/news-insights/chrononutrition-food-timing-circadian-fasting-and-the-bodys-internal-clock/?utm_campaign=Newsletter&utm_medium=email&_hsmi=251085985&_hsenc=p2ANqtz-8T_k3YJCFivLIRpT-UCW4IK1x8vKKGfijKRnr4-astzNGhHDqTj9WiCepB_vUcJE-ZK70SXU68vmHZtY9rEmT8JsGpZA&utm_content=251085983&utm_source=hs_email> References: 1) Leng Y, Musiek ES, Hu K, Cappuccio FP, Yaffe K. Association between circadian rhythms and neurodegenerative diseases. Lancet Neurol. 2019;18(3):307-318. doi:1016/S1474-4422(18)30461-7 2) Chaput JP, McHill AW, Cox RC, et al. The role of insufficient sleep and circadian misalignment in obesity. Nat Rev Endocrinol. 2023;19(2):82-97. doi:1038/s41574-022-00747-7 3) Serin Y, Acar Tek N. Effect of circadian rhythm on metabolic processes and the regulation of energy balance. Ann Nutr Metab. 2019;74(4):322-330. doi:1159/000500071 4) Flanagan A, Bechtold DA, Pot GK, Johnston JD. Chrono-nutrition: From molecular and neuronal mechanisms to human epidemiology and timed feeding patterns. J Neurochem. 2021;157(1):53-72. doi:1111/jnc.15246 5) Young IE, Poobalan A, Steinbeck K, O’Connor HT, Parker HM. Distribution of energy intake across the day and weight loss: a systematic review and meta-analysis. Obes Rev. 2023;24(3):e13537. doi:1111/obr.13537 6) Mason IC, Qian J, Adler GK, Scheer FAJL. Impact of circadian disruption on glucose metabolism: implications for type 2 diabetes. Diabetologia. 2020;63(3):462-472. doi:1007/s00125-019-05059-6 7) Leung GKW, Huggins CE, Ware RS, Bonham MP. Time of day difference in postprandial glucose and insulin responses: systematic review and meta-analysis of acute postprandial studies. Chronobiol Int. 2020;37(3):311-326. doi:1080/07420528.2019.1683856 8) de Almeida RS, Marot LP, Latorraca COC, Oliveira RÁ, Crispim CA. Is evening carbohydrate intake in healthy individuals associated with higher postprandial glycemia and insulinemia when compared to morning intake? A systematic review and meta-analysis of randomized crossover studies. J Am Nutr Assoc. Published online March 1, 2022. doi:1080/07315724.2022.2043199 9) Adafer R, Messaadi W, Meddahi M, et al. Food timing, circadian rhythm and chrononutrition: a systematic review of time-restricted eating’s effects on human health. Nutrients. 2020;12(12):3770. doi:3390/nu12123770  10) Zeb F, Wu X, Fatima S, et al. Time-restricted feeding regulates molecular mechanisms with involvement of circadian rhythm to prevent metabolic diseases. Nutrition. 2021;89:111244. doi:1016/j.nut.2021.111244  11) Tsitsou S, Zacharodimos N, Poulia KA, Karatzi K, Dimitriadis G, Papakonstantinou E. Effects of time-restricted feeding and Ramadan fasting on body weight, body composition, glucose responses, and insulin resistance: a systematic review of randomized controlled trials. Nutrients. 2022;14(22):4778. doi:3390/nu14224778  12) Perez-Diaz-Del-Campo N, Castelnuovo G, Caviglia GP, Armandi A, Rosso C, Bugianesi E. Role of circadian clock on the pathogenesis and lifestyle management in non-alcoholic fatty liver disease. Nutrients. 2022;14(23):5053. doi:3390/nu14235053 13) Kord-Varkaneh H, Salehi-Sahlabadi A, Tinsley GM, Santos HO, Hekmatdoost A. Effects of time-restricted feeding (16/8) combined with a low-sugar diet on the management of non-alcoholic fatty liver disease: a randomized controlled trial. Nutrition. 2023;105:111847. doi:1016/j.nut.2022.111847  14) Xie Z, He Z, Ye Y, Mao Y. Effects of time-restricted feeding with different feeding windows on metabolic health: a systematic review of human studies. Nutrition. 2022;102:111764. doi:1016/j.nut.2022.111764  15) Ramos-Lopez O, Martinez-Urbistondo D, Vargas-Nuñez JA, Martinez JA. The role of nutrition on meta-inflammation: insights and potential targets in communicable and chronic disease management. Curr Obes Rep. 2022;11(4):305-335. doi:1007/s13679-022-00490-0  16) Currenti W, Godos J, Castellano S, et al. Association between time restricted feeding and cognitive status in older Italian adults. Nutrients. 2021;13(1):191. doi:3390/nu13010191  17) Palomar-Cros A, Espinosa A, Straif K, et al. The association of nighttime fasting duration and prostate cancer risk: results from the Multicase-Control (MCC) study in Spain. Nutrients. 2021;13(8):2662. doi:3390/nu13082662  18)Prasad M, Fine K, Gee A, et al. A smartphone intervention to promote time restricted eating reduces body weight and blood pressure in adults with overweight and obesity: a pilot study. Nutrients. 2021;13(7):2148. doi:3390/nu13072148  19) Beaulieu K, Oustric P, Alkahtani S, et al. Impact of meal timing and chronotype on food reward and appetite control in young adults. Nutrients. 2020;12(5):1506. doi:3390/nu12051506  20) Sempere-Rubio N, Aguas M, Faubel R. Association between chronotype, physical activity and sedentary behaviour: a systematic review. Int J Environ Res Public Health. 2022;19(15):9646. doi:3390/ijerph19159646  21) Barrea L, Vetrani C, Altieri B, et al. The importance of being a ‘lark’ in post-menopausal women with obesity: a ploy to prevent type 2 diabetes mellitus? Nutrients. 2021;13(11):3762. doi:3390/nu13113762  22) Mazri FH, Manaf ZA, Shahar S, Mat Ludin AF, Abdul Basir SM. Development and evaluation of integrated chrono-nutrition weight reduction program among overweight/obese with morning and evening chronotypes. Int J Environ Res Public Health. 2022;19(8):4469. doi:3390/ijerph19084469 Related Articles CHRONOBIOLOGY: THE DYNAMIC FIELD OF RHYTHM AND CLOCK GENES CIRCADIAN FASTING & PRECURSORS TO HEART HEALTH PERSONALIZING NUTRITIONAL INTERVENTIONS

Alternate day fasting and it's metabolic benefits

 

Alternate-Day Fasting in Short Term Safe, Has Metabolic Benefits

Alternate-day fasting (ADF) had positive effects on body weight, cardiovascular measures, and molecular markers of aging when assessed in a randomized controlled trial among healthy adults without obesity or diabetes, researchers report in a study published online August 27, 2019 in Cell Metabolism.

ADF is a different approach to control weight than the common caloric restriction (CR) or intermittent fasting (IF) that restricts daily eating to an 8- to 12-hour window. Although ADF is gaining popularity it has not been subject to randomized clinical trials.

Therefore, Slaven Stekovic, PhD, from the Institute of Molecular Biosciences at the University of Graz in Austria, and colleagues conducted a prospective cohort study with an embedded randomized controlled trial to assess the metabolic effects of ADF. The team initially recruited 30 participants who had followed ADF for at least 6 months before the study began and compared them to 60 healthy controls. Thirty members of the control group were then randomly assigned to ADF for 4 weeks and the other 30 participants ate whatever and whenever they wanted during that time.

Specifically, the 30 people who had followed ADF for 6 months or more and the 30 individuals randomly assigned to ADF alternated between 36 hours of not eating and 12 hours of eating whatever they wanted. These two groups were similar in terms of gender distribution, age, body mass index (BMI), and waist-to-hip ratio at baseline.

Before and after the intervention, participants underwent a battery of anthropometric, physiological, hormonal, metabolic, and biochemical measurements that reflect health status and possible effects of ADF. These included measures of body composition and cardiovascular function, caloric expenditure assessed using food frequency and exercise questionnaires, and bone mineral density at the lumbar spine.

No adverse effects were seen among participants in the ADF group. Their caloric intake dropped from baseline by 37.4% (95% CI, –48.3% to –24.4%), compared with 8.2% (95% CI, –32.2% to 3.6%) in the control group.

BMI among the 4-week fasters fell by 1.2 kg/m2 (95% CI, –1.515 to –0.875; P < .0001). The average reduction in belly fat was 14.5% ± 6.4% (P < .0001).
In addition to changes in body mass and composition, researchers noted metabolic trends, which is why they chose to publish in Cell Metabolism rather than a more general journal. "Cell Metabolism is very open to translational findings and there is probably no other intervention that changes the metabolism of an organism as profoundly as fasting," co-author Frank Madeo, PhD, a professor at the Institute for Molecular Biosciences at the University of Graz in Austria, told Medscape Medical News.

Co-author Harald Sourij, MD, a professor at the Medical University of Graz, summarized the metabolic findings: "Overall a number of changes associated with reduced cardiovascular risk and aging were detected, including reduction in inflammatory markers such as sICAM-1, systolic blood pressure, levels of LDL cholesterol, short-chain fatty acids, and triiodothyronine; increase in polyunsaturated fatty acids; and downregulation of potential pro-aging amino acids, such as methionine.”

The metabolic findings suggest that ADF may be safer than CR, which is more widely practiced.

"CR was previously associated with concerns about bone metabolism or immune cell function. Neither in our short-term randomized, controlled study nor in the 6-months ADF cohort did we observe adverse effects on bone mass, total white blood cell count, or abundance of immune cell subtypes, red blood cell counts, or iron metabolism," Sourij told Medscape Medical News.

He cautions though that longer prospective investigations are needed to monitor these parameters over years to rule out potential adverse effects or development of nutrient deficiencies.

The study didn't compare ADF to IF. "Losing 7 pounds within 4 weeks, as in our study, is a strong weight loss effect that will probably not be achieved by shorter fasting periods. ADF has profound positive effects on body weight, cardiovascular parameters, and molecular markers of aging," Madeo concluded.

The apparent safety of ADF may arise from its mimicking eating patterns of our hunter-and-gatherer forebears, explained Madeo. "Our physiology is familiar with periods of starvation followed by food excesses," he said. For example, starvation sets in motion autophagy, in which cells dismantle and recycle damaged parts, such as organelles and proteins, associated with aging. "Autophagy improves the metabolic functions of cells, and it is switched on after 36 hours of fasting," he said.

The autophagy angle may explain the apparent inferiority of CR. "Low-calorie intake hinders the induction of the age-protective autophagy program, which is switched on during fasting breaks," Madeo continued.

But the researchers caution that we don't yet know the consequences, if any, of strict ADF beyond 6 months, and they suggest a robust comparison of "different fasting regimens with each other and across different cohort types," they write. They also warn that constant bombardment with images of food and easy access to it may hamper attempts at ADF for some individuals, and effects may be ephemeral if the pattern of fasting and eating is abandoned.

The investigators stress the importance of identifying patients who likely cannot thrive on ADF. "Appreciable clinical support and a generally healthy lifestyle should be considered before starting ADF," they write.

That caveat is consistent with a 2017 study by John Trepanowski, PhD, of the department of kinesiology and nutrition at the University of Illinois, Chicago, and colleagues that compared ADF, CR, and no intervention among 100 otherwise healthy obese adults. They found no advantage of ADF over CR for adherence, weight loss, weight maintenance, or cardioprotection.

Yoni Freedhoff, MD, associate professor of family medicine at the University of Ottawa, Ontario, Canada, echoes the cautionary comments.

"ADF is already a clinically relevant intervention if employing it allows a person to lose weight and consequently improve weight-responsive medical conditions, but whether or not it has any long-term risks, or benefits beyond those attributable simply to weight loss, will require long-term study. Of course, as with any intervention for a chronic disease, if the intervention is only temporary and ADF as a lifestyle is abandoned following some health improvements, those improvements are likely only to be temporary as well.”

Limitations of the investigation included enrollment of a small sample of highly motivated individuals who were interested in or already doing ADF.

Sourij has reported receiving unrestricted research grants from AstraZeneca, MSD, and Sanofi-Aventis. The other authors and commentator have reported no relevant financial relationships.

Cell Metab. Published online August 27, 2019.