Gut microbiota changes associated with low-carbohydrate diet intervention for obesity.

Low-carbohydrate diets (LCDs) are frequently recommended for alleviating obesity, and the gut microbiota plays key roles in energy metabolism and weight loss. However, there is limited in-human research on how LCD changes gut microbiota. In this before-after study, 43 participants were assigned to the LCD intervention for 4 weeks. The main objective was to investigate the specific changes that occur in the participants' microbiome in response to the LCD. Changes in gut microbiota were analyzed using 16s rRNA sequencing. Body composition was measured using InBody 770. Remarkably, 35 participants (79.07%) lost more than 5% of their body weight; levels of BMI, body fat, and total cholesterol were significantly decreased, indicating the effectiveness of the LCD intervention. The richness of microbiota significantly increased after the intervention. By taking the intersection of ANOVA and linear discriminant analysis effect size (LEfSe) analysis results, we identified three phyla, three classes, four orders, five families, and six genera that were differentially enriched between baseline and week-4 time points. Among the three phyla, relative abundances of Firmicutes and Actinobacteriota decreased significantly, while Bacteroidetes increased significantly. At the genus level, Ruminococcus, Agathobacter, Streptococcus, and Bifidobacterium showed a significant reduction in relative abundances, whereas Parabacteroides and Bacteroides increased steadily. Our results demonstrate that LCD can effectively alleviate obesity and modify certain taxa of gut microbiota, providing potential insights for personalized dietary interventions against obesity.

Multiplicity and complexity of food environment in China: full-scale field census of food outlets in a typical district.

OBJECTIVES: Community food environment is closely associated with residents' health status, and it has received substantial research attention in recent years. However, such studies are sparse in China. This study aims to reveal the characteristics of food environment in China. SUBJECTS: A ground-truthing field census of food outlets was conducted in Xi Hu district, Hangzhou. A novel categorizing system was developed to better characterize food outlets in the study area. Geocoding and food environment analysis were performed by Arc-GIS software. RESULTS: A total of 9274 food outlets were identified, of these, 6161 (66.43%) were food service places and 3113 (33.57%) were food stores. Fast-food restaurants (2692) and convenience stores (1764) were the two most numerous outlet types. The density of food outlets was 29.72/km2 and 113.97/10,000 people. Availability of BMI-unhealthy food outlets was four times greater than that of BMI-healthy ones. Further, 41.86% of total food outlets provided food-delivery services; among them, fast-food restaurants were the highest (65.53%) providers. In the urban area, the average density of food outlets was 104/km2. While, it was only 29/km2 in the rural area. CONCLUSIONS: Availability of food outlets was excellent in our study area, though it showed regional imbalance. Food environment tends to be obesogenic and high prevalence of food delivery service might increase this trend. Thus, policy makers should guarantee the smooth development of catering industry in China, so as to ensure a balanced nutrition environment.

How we eat determines what we become: opportunities and challenges brought by food delivery industry in a changing world in China.

Rapid economic growth and urbanization have brought notable changes in China. This trend had dramatic impacts to food industry and diet-related behaviors, which leads to increasing prevalence of overweight and obesity as well as diet-related non-communicable diseases (NCDs). With a rapid development of internet and e-commerce market, another emerging trend that should not be overlooked is the change in food shopping habits induced by the popularity of online-to-offline (O2O) food delivery service in China. The O2O food market is a booming industry in China, the market scale of O2O food industry is increasing with remarkable speed. More than 1/5 of total population in China has already became the users of O2O food delivery market. Development of this new trend in food environment is inevitable. This game-changing trend brings great opportunities to improve food accessibility and availability but meanwhile poses inevitable challenges to the whole public health system and social environment in China. This paper offers a unique perspective of the opportunities and challenges that the new industry brings to food environment, health outcomes caused by related behavior change, and its broader influence on social environment.