5-Heptadecylresorcinol (AR-C17), a primary biomarker of whole grain (WG) consumption, has been demonstrated to improve the thermogenic activity of aging mice. However, the intricate regulatory mechanism is not fully understood. This study conducted metabolomics analysis on young and aging mice with or without AR-C17 administration after cold exposure. The results showed that the aging mice displayed lower levels of acylcarnitine (ACar) in their plasma compared with the young mice during cold exposure, and 150 mg/kg/day of AR-C17 administration for 8 weeks could increase the plasma ACar levels of aging mice. ACar has been reported to be an essential metabolic fuel for the thermogenesis of brown adipose tissue (BAT). AR-C17 had similar effects on the ACar levels in the BAT as on the plasma of the aging mice during cold exposure. Furthermore, the aging mice had reduced ACar metabolism in the BAT, and AR-C17 could improve the ACar metabolism in the BAT of aging mice, thereby promoting the metabolic utilization of ACar by BAT. Moreover, the glucose and lipid levels of aging mice could be improved by AR-C17. This study revealed a deeper metabolic mechanism involved in the AR-C17-mediated thermogenic regulation of BAT, providing a new theoretical basis for the nutrition and health benefits of WG.

Type 2 diabetes is associated with many complications, including skeletal muscle atrophy. Ketogenic diets and low-carbohydrate diets (LCD) have recently been introduced as dietary interventions in patients with diabetes, but their effects on glucose and lipid metabolism in skeletal muscle have not been studied. In the current study, we compared the effects of LCD and ketogenic diet on glucose and lipid metabolism in skeletal muscle of diabetic mice. C57BL/6J mice with type 2 diabetes, constructed by a high-fat diet combined with streptozotocin, were fed a standard diet, a high-fat diet, an LCD, or a ketogenic diet for 14 weeks, respectively. Here, we found that the LCD, rather than the ketogenic diet, retained skeletal muscle weight and suppressed the expression of atrophy-related genes in diabetic mice. In addition, the LCD had more glycolytic/type IIb myofiber content and inhibited forkhead box O1 and pyruvate dehydrogenase kinase 4 expression, leading to improved glucose utilization. However, the ketogenic diet maintained more oxidative/type I myofibers. Moreover, compared with the ketogenic diet, the LCD decreased intramuscular triglycerides content and muscle lipolysis, suggesting improvement in lipid metabolism. Taken together, these data suggested that the LCD improved glucose utilization, and inhibited lipolysis and atrophy in skeletal muscle of diabetic mice, while the ketogenic diet showed metabolic disorders in skeletal muscle.

A balanced diet is considered necessary in maternal recovery and neonatal development; however, the dietary quality of lactating mothers in China has not been systematically evaluated in different regions and stages of lactation. In addition, the release of the Chinese Dietary Guidelines in 2022 implies that the dietary index method needs to be adjusted accordingly. In this study, the adjusted Chinese Dietary Balance Index-16 (DBI-16) was used to assess the dietary quality of lactating women, referred to as the Dietary Balance Index for lactating women (DBI-L). This study is part of the MUAI study, in which dietary intake and demographic characteristics of lactating mothers from six cities in China and at different stages of lactation were obtained through a self-administered questionnaire and a food frequency questionnaire; 2532 puerperal women were included. According to the DBI-L, 66.2% of participants had inadequate dietary intake (79.1% vegetables, 79.1% fruits, 86.7% dairy products, 39.7% soybeans, and 69.4% fish products, respectively), 57.8% had excessive intake (76.0% cereals, 64.4% meat, and 29.1% eggs, respectively) and 92.2% had unbalanced dietary consumption. Dietary quality was optimal for mothers in the first month after delivery, and the dietary quality of mothers in economically developed places such as Shanghai and Guangzhou was significantly better than that in less developed places such as Lanzhou and Changchun. The dietary quality of lactating women in China is imbalanced, with excessive and inadequate dietary intake. The country should strengthen nutritional interventions for lactating mothers, especially in economically underdeveloped regions.