Exploring the Link Between Plant-Based Diets and Resting Metabolic Rate in Women With Overweight and Obesity: Implications for Weight Management and Metabolic Health.

Obesity is a global health issue linked to increased risks of type 2 diabetes and cardiovascular diseases. A reduced resting metabolic rate contributes to obesity. Plant-based diets are often recommended for weight control, but their effect on resting metabolic rate is underexplored. This study assesses the association between plant-based dietary patterns and resting metabolic rate in women with overweight and obesity. In this cross-sectional study, 285 women with overweight and obesity were selected from health centers in Tehran. Body composition was measured using bioelectrical impedance analysis, dietary intake was assessed using a semi-quantitative food frequency questionnaire. Adherence to plant-based diets was evaluated through three indices: the overall plant-based diet index, the healthful plant-based diet index and the unhealthful plant-based diet index. Resting metabolic rate was measured via indirect calorimetry. Higher plant-based diet index and healthful plant-based diet index scores were significantly associated with increased resting metabolic rate per kilogram of body weight, even after adjusting for confounders. Conversely, higher unhealthful plant-based diet index scores were linked to lower resting metabolic rate per kilogram. Participants with higher adherence to plant-based diet index reported greater intakes of energy, most macronutrients and several micronutrients, while those with higher adherence to the unhealthful plant-based diet index reported lower intakes of energy and selected nutrients. Greater adherence to healthful plant-based diets is associated with a higher resting metabolic rate in women with overweight and obesity, suggesting potential benefits for weight management and metabolic health.