Purpose The menopausal transition (MT) is a period when there may be an increase in visceral fat mass and a worsening of cardiometabolic risk factors. Few studies have evaluated the efficacy of plant-based low-calorie diets on groups of women at different stages of MT. The purpose of this study is to compare the effectiveness of a high plant-to-animal protein ratio diet in women of similar age but with different fertility statuses. Design/methodology/approach Subjects were divided into three groups according to their fertility status at the baseline: “premenopausal” (n = 11), “perimenopause” (n = 14) and “postmenopause” (n = 18). Body composition (BC) was measured at the beginning and after eight months of treatment. Individualised lifestyle treatment included a strong component of plant-based foods. Findings Forty-three overweight or obese Caucasian women (age 52.3 ± 4.5 years, body mass index 30.6 ± 5.4 kg/m2, fat mass 33.1 ± 9.3 kg data presented as means ± SD) were included in the study. Mean physical activity was 8.4 ± 7.6 metabolic equivalent of tasks/week. Subjects had an improvement in BC (fat mass −5.6 ± 4.0 kg, p < 0.001 protein −0.3 ± 0.5 kg, p < 0.001), HDL-C and systolic blood pressure values. Waist circumference and hip circumference decreased by 4.1 ± 3.1 cm and −6.0 ± 4.3 cm, respectively. Weight loss resulted in a significant improvement in some blood lipid values, such as total and high-density lipoprotein cholesterol. Adherence to a high plant protein diet helps adult women with different fertility statuses to improve BC and reduce cardiovascular risk factors. Long-term studies with larger sample sizes are needed to confirm these findings. Originality/value In pre-peri- and post-menopausal adult women, a diet high in plant proteins improves body composition and reduces cardiovascular risk factors.