New study highlights the impact of plant-based and sustainable diets on obesity
A systematic review, published in our journal Obesity Reviews, explores the relationship between plant-based diets and their effects on obesity.
The study, conducted by researchers from the University of Milan and IRCCS Istituto Auxologico Italiano, highlights the health and environmental benefits of sustainable diets, particularly those modelled on the EAT-Lancet framework.
Obesity and climate change pose interlinked global health and environmental challenges. The adoption of good food production and consumption practices towards sustainable dietary patterns are an important strategy to address both crises. This systematic review examines how adopting plant-based diets impacts obesity and related health outcomes.
Lower obesity rates with plant-based diets
The review analysed six high-quality studies, including over 11,000 participants. Findings suggest that adherence to plant-based diets, particularly healthy plant-based diets (hPBDs), is associated with a reduced risk of obesity and weight regain compared to normal or animal -based diets. Notably, individuals with higher adherence to plant-based diets experienced greater reductions in BMI and body fat compared to those following other diets. The mechanism behind the effect of plant-based diets may lie in the energy density of the food consumed (which usually contains less fat, more water and more fibre, especially in the hPDI variant), leading people to feel fuller for longer and eat less calories overall.
In addition to weight management, plant-based diets were linked to improvements in key cardiometabolic markers, including glycaemic control, cholesterol levels, and blood pressure.
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Not all plant-based diets are healthy
The review also highlighted the variability in results depending on the type of plant-based diet. While healthy plant-based diets—characterised by whole grains, fruits, vegetables, nuts, and legumes—showed significant benefits, unhealthy plant-based diets (uPBDs) rich in refined grains, sugary beverages, and processed foods were associated with an increased risk of obesity and abdominal adiposity.
Environmental and health co-benefits
The researchers emphasise that healthy plant-based diets not only improve individual health outcomes but also reduce the environmental impacts of animal-based diets, such as greenhouse gas emissions, water and land use. By aligning dietary choices with sustainability goals, policies to promote these diets can contribute to mitigating climate change while promoting public health.
Recommendations for future research
The study calls for more robust longitudinal and intervention studies to better understand the long-term effects of plant-based diets on obesity and to explore culturally specific adaptations of sustainable diets, such as the EAT-IT diet in Italy.
The authors highlight the need for standardised definitions and measurements of plant-based diets to ensure consistency across studies.
READ THE STUDYThis comprehensive review underscores the potential of healthy plant-based diets to combat obesity and promote sustainability. As obesity rates and environmental pressures continue to rise, adopting sustainable dietary patterns offers a ‘win-win’ solution to these interlinked global challenges.
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World Obesity publishes four scientific, peer-reviewed journals, each focusing on a different area of obesity research: systematic reviews, pediatrics, clinical treatment, and science and practice.
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