Thank you for visiting nature. Funding This research received no external funding. The upregulation of mitochondrial membrane uncoupling proteins UCP may be partly responsible for these effects. Precise evidence for underlying mechanisms is missing; however, more recently it has been suggested that high fiber intake induces changes on the microbial level leading to lower long-term weight gain 58, a mechanism discussed below. Hjorth, M. Dietary behavior is complex, and attention to social and cultural norms influencing dietary choices and preferences will better equip nutrition educators to help shine a more positive light on plant-based diets in places where pejorative perception rather than price is a barrier to consumption. Open in new tab. Some specifically vegan gut microbial characteristics have also been found in a small sample of six obese subjects after 1 month following a vegetarian diet, namely less pathobionts, more protective bacterial species improving lipid metabolism and a reduced level of intestinal inflammation
Obesity affects over one-third of Americans and increases the risk of cardiovascular disease and type II diabetes. Interventional trials have consistently demonstrated that consumption of plant-based diets reduces body fat in overweight and obese subjects, even when controlling for energy intake. Nonetheless, the mechanisms underlying this effect have not been well-defined. This review discusses six major dietary mechanisms that may lead to reduced body fat. These include 1 reduced caloric density, 2 improved gut microbiota symbiosis, 3 increased insulin sensitivity, 4 reduced trimethylamine-N-oxide TMAO, 5 activation of peroxisome proliferator-activated receptors PPARs, and 6 over-expression of mitochondrial uncoupling proteins. Collectively, these factors improve satiety and increase energy expenditure leading to reduced body weight. The Centers for Disease Control and Prevention estimates that Obesity may shorten human lifespan by 4—7 years, presumably due to the associated increased chronic disease risks for type II diabetes mellitus T2DM, cardiovascular disease CVD, and cancer [ 3, 4, 5 ]. While a variety of environmental factors influence the development of obesity, diet has a significant influence on adiposity [ 6 ].
Eating a diet high in plant-based foods and low in animal-based foods may protect against obesity in middle aged and elderly populations, even if a vegetarian or vegan diet is not strictly followed. Previous evidence suggests that vegan or vegetarian diets high in plant-based foods and that eliminate all or the vast majority of animal products–may cut the risk of developing obesity. To investigate this further, Zhangling Chen, and colleagues from Erasmuc MC Rotterdam in the Netherlands examined the association between varying degrees of plant-based diet and body mass index BMI, waist circumference, fat mass index fat weight relative to height, fat-free mass index, and body fat percentage over the long term in 9, middle-aged and elderly adults average age 62 years from the Rotterdam Study–an ongoing population-based study in The Netherlands. Dietary data were collected using a detailed food frequency questionnaire at the start of each of three sub-cohorts , , and From that, the researchers created a plant-based diet index to score the degree of plant-based foods versus animal-based foods for each participant. Participants earned positive scores for eating plant-based foods such as nuts, fruits, and vegetables, and were given negative scores for eating animal foods like meat, dairy, and fish. A higher score indicated better adherence to a diet high in plant-based foods and low in animal-based products. Between and , participants had their height, weight, and waist circumference repeatedly measured every 3 to 5 years, while fat mass and fat-free mass were measured using dual x-ray absorptiometry DXA scanning every 3 to 5 years from to Analyses showed that participants who had higher scores on the plant-based diet index had a lower BMI over the long term, mainly due to lower body fat mass, after adjusting for the effects of time of repeated measurements, total energy intake, education, socioeconomic background, and physical activity levels. Compared with participants with a zero points score on the index, participants with a 10 point score had 0.