Intermittent fasting combined with exercise training reduces body mass and alleviates hypothalamic disorders induced by high-fat diet intake

Excessive or sustained endoplasmic reticulum stress: one of the culprits of adipocyte dysfunction in obesity

As the prevalence of obesity continues to rise globally, the research on adipocytes has attracted more and more attention. In the presence of nutrient overload, adipocytes are exposed to pressures such as hypoxia, inflammation, mechanical stress, metabolite, and oxidative stress that can lead to organelle dysfunction. Endoplasmic reticulum (ER) is a vital organelle for sensing cellular pressure, and its homeostasis is essential for maintaining adipocyte function. Under conditions of excess nutrition, ER stress (ERS) will be triggered by the gathering of abnormally folded proteins in the ER lumen, resulting in the activation of a signaling response known as the unfolded protein responses (UPRs), which is a response system to relieve ERS and restore ER homeostasis. However, if the UPRs fail to rescue ER homeostasis, ERS will activate pathways to damage cells. Studies have shown a role for disturbed activation of adipocyte ERS in the pathophysiology of obesity and its complications. Prolonged or excessive ERS in adipocytes can aggravate lipolysis, insulin resistance, and apoptosis and affect the bioactive molecule production. In addition, ERS also impacts the expression of some important genes. In view of the fact that ERS influences adipocyte function through various mechanisms, targeting ERS may be a viable strategy to treat obesity. This article summarizes the effects of ERS on adipocytes during obesity.

Effects of intermittent fasting combined with exercise on serum leptin and adiponectin in adults with or without obesity: a systematic review and meta-analysis of randomized clinical trials

Context

Intermittent fasting (IF) and exercise training (Exe) have been evaluated in several studies for improving cardiometabolic biomarkers related to weight loss. However, further investigation is required to understand the potential effects on leptin and adiponectin concentrations. IF protocols have been shown to be efficient in improving adipokines, but further research is required to determine whether or not IF regimens combined with Exe are superior to Exe alone.

Objective

The aim of this study was to determine whether or not interventions combining IF plus Exe are more effective than Exe only for improving serum leptin and adiponectin in adults with and without obesity.

Data extraction

A systematic review and meta-analysis was performed by searching PubMed, Scopus, and Web of Science databases up to August 2023 for randomized clinical trials that determined the effects of IF plus Exe vs. Exe alone (control) on body weight, serum leptin, and serum adiponectin. Analyses were conducted for IF plus Exe vs. Exe alone to calculate weighted mean differences (WMD) and standardized mean differences (SMD).

Analysis

The current meta-analysis included 6 studies with a total sample of 153 participants, with intervention durations ranging from three days to 52 weeks. IF plus Exe elicited significantly larger decreases in leptin levels [SMD = -0.47, p = 0.03], which were accompanied by weight loss [WMD = -1.25 kg, p = 0.05], as compared with exercise-only interventions, but adiponectin did not differ between the two [SMD = 0.02, p = 0.9].

Conclusion

IF combined with Exe reduced leptin significantly, but did not change adiponectin levels, when compared to exercise only. Perhaps these reductions in leptin levels may have been associated with weight loss; however, due to the small number of included studies and the high heterogeneity in the weight loss outcomes, this result is uncertain.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42023460735.

Association of a High Healthy Eating Index Diet with Long-Term Visceral Fat Loss in a Large Longitudinal Study

We aimed to investigate the association of a sustainable diet with a long-term reduction in waist circumference (WC) while identifying novel biomarkers for WC reduction (WCR). The participants were recruited initially during 2004-2013 in a large hospital-based cohort, and the follow-up measurements were conducted during 2012-2016. The 65,611 adults aged 45-75 were categorized into WC-loss (n = 22,290) and WC-gain (n = 43,321). Each study investigated demographic, anthropometric, biochemical, genetic, and dietary factors. The modified Healthy Eating Index (MHEI), dietary patterns, and glycemic index were calculated from a validated semi-quantitative food frequency questionnaire. Novel biomarkers influencing WC reduction were identified using machine learning approaches. A WCR was inversely associated with metabolic syndrome (MetS) risk and its components. Daily energy intake did not differ between those with and without WCR. However, MHEI, which represents diet quality, demonstrated a positive association with WCR. Among various dietary patterns, the Asian-style balanced diet (ABD), including more fermented soybeans and less restricted salt than the Diet Approach to Stop Hypertension, was positively associated with WCR. However, an inverse association was observed between the diet that was high in noodle and processed meat consumption and that which was high in rice consumption. However, the PRS for abdominal obesity did not significantly interrupt WCR. The receiver operating characteristic curve in the prediction model for WCR was about 0.86. The biomarkers in the models included MetS components, inflammation index, diet components, alcohol consumption, and smoking status, but not genetic factors. In conclusion, adopting a high-quality diet with a high MHEI like ABD leads to WCR, irrespective of genetic influences. These results could be applied to develop effective strategies for preventing and managing abdominal obesity.