Intermittent fasting entails restricting food intake during specific times of day, days of the week, religious practice, or surrounding clinically important events. Herein, the metabolic and circadian rhythm mechanisms underlying the proposed benefits of intermittent fasting for the cancer population are described. We summarize epidemiological, preclinical, and clinical studies in cancer published between January 2020 and August 2022 and propose avenues for future research. An outstanding concern regarding the use of intermittent fasting among cancer patients is that fasting often results in caloric restriction, which can put patients already prone to malnutrition, cachexia, or sarcopenia at risk. Although clinical trials do not yet provide sufficient data to support the general use of intermittent fasting in clinical practice, this summary may be useful for patients, caregivers, and clinicians who are exploring intermittent fasting as part of their cancer journey for clinical outcomes and symptom management.

Intermittent fasting (IF) and caloric restriction (CR) are dietary strategies to prevent and attenuate obesity associated with conditions and aging-related outcomes. This scoping review examined the cardiometabolic, cancer, and neurocognitive outcome differences between IF and CR interventions among adults. We applied a systematic approach to scope published randomized controlled trials (databases: PubMed, CINAHL Plus, PsychInfo, Scopus, and Google Scholar) from inception through August 2023. The initial search provided 389 unique articles which were critically appraised. Thirty articles met the eligibility criteria for inclusion: 12 were IF, 10 were CR, and 8 were combined IF and CR interventions. IF and CR were associated with weight loss; however, IF studies tended to report greater adherence compared with CR. Overall, IF and CR were equivalently effective across cardiometabolic, cancer, and neurocognitive outcomes. Our findings suggest that IF has health benefits in a variety of conditions and may be better accepted and tolerated than CR, but more comparative research is required.

Background: Tai Chi, originating in China, is a mind–body exercise that integrates mind training, Qi training, and body training. While Tai Chi practice has demonstrated beneficial physical and psychological health benefits, how it achieves effects has been less studied. In recent years, some researchers have begun to explore the potential of heart rate variability (HRV) changes as balancing the autonomic nervous system (ANS) to achieve results, but only a few studies have directly tested how Tai Chi impacts HRV, and results have been mixed. Objective: This study systematically evaluates the effects of Tai Chi on HRV. Methods: Electronic databases including Web of Science, PubMed, Scopus, Cochrane Library, and EBSCOhost direct from inception until December 2020 were searched to obtain eligible studies. The primary outcomes examined were HRV parameters (time domain and frequency domain), and secondary analysis was whether breathing was emphasized during Tai Chi interventions. Results: Based on the 11 randomized controlled trials included comparing Tai Chi with non-active control condition, meta-analyses showed significantly beneficial effects on HRV parameters (low-frequency power [LF], mean difference [MD] = −200.40, 95% confidence interval [CI]: 365.31 to −35.49, p = 0.02; normalized low-frequency power [nLF], MD = −7.39, 95% CI: −12.48 to −2.29, p = 0.004; total power [TP], MD = −649.82, 95% CI: −1180.54 to −119.11, p = 0.02; very low-frequency power [VLF], MD = −200.55, 95% CI: −349.63 to −51.46, p = 0.008; root mean square of the square sum of the difference between adjacent normal heartbeat intervals [RMSSD], MD = 2.59, 95% CI: −7.23 to 12.41, p < 0.0001; standard deviation of the heartbeat interval [SDNN], MD = 8.33, 95% CI: 0.69 to 15.98, p = 0.03). The effect of Tai Chi on certain HRV parameters compared with active control conditions was less favorable (nLF, MD = 6.42, 95% CI: 3.74 to 9.09, p < 0.00001; normalized high-frequency power [nHF], MD: −6.13, 95% CI: −8.76 to −3.50, p < 0.00001; low-frequency/high-frequency power ratio [LF/HF], MD = 1.00, 95% CI: 0.68 to 1.33, p < 0.00001). In addition, studies describing an emphasis on breathing in the Tai Chi intervention showed positive impact on HRV (nLF, MD = −3.22, 95% CI: −5.32 to −1.12, p = 0.003; nHF, MD = 3.80, 95% CI: 0.80 to 6.81, p = 0.01; SDNN, MD = 5.55, 95% CI: 4.85 to 6.25, p < 0.00001). Conclusions: Meta-analysis results showed that Tai Chi compared with non-active control conditions has a positive impact on key HRV parameters associated with the ANS balance. However, active control condition comparisons showed greater HRV improvements than for Tai Chi. Considering the limited number of studies and their heterogeneity, further robust studies are necessary to verify findings and investigate differential effects of Tai Chi on HRV.

Weight gain and related adverse changes in body composition are prevalent among midlife and older women and contribute to chronic disease (e.g., type 2 diabetes, hypertension, depression). Tai Chi (TC) and Qigong (QG), forms of Meditative Movement, demonstrate improved physical/psychological symptoms and body composition. Using a standardized TC/QG protocol, we explored pre/post intervention differences in percent body fat and factors related to body composition in midlife/older women. In the context of a single-group pilot study, females ages 45–75 (N = 51) enrolled in an 8-week TC/QG intervention. Primary outcome measures of body composition, sleep quality, emotional eating and select secondary outcome psycho-emotional factors (perceived stress, mood state, mindfulness, self-compassion, body awareness) were collected. Change in percent body fat did not reach statistical significance (p = .30, M = 0.35, 95% CI [- 0.32, 1.0]). Sleep quality improved significantly, p = .04, M = – 0.88, 95% CI [−1.71, – 0.04]. Emotional eating changed in the expected direction, but not significantly, p = .08, M = −0.16, 95% CI [−0.34, 0.02]. Significant differences were found in body awareness, p = .01, M = 0.36, 95% CI [0.08, 0.63] and perceived stress, p = .05, M = −2.36, 95% CI [−4.76, 0.04]. Preliminary results are promising as results showed improvements in factors related to healthy body composition. Refined research is needed to understand if/how TC/QG may improve body composition among midlife and older women.