This study has found that, in post-menopausal women the habitual soy intake has a beneficial effect on bone mass, particularly after the initial years of dramatic hormonal change. At least 40 mg of soy isoflavones per day seem to be necessary to exert the effect but it is probable that a higher intake is required to achieve optimal effects on bone health. At least one glass of soy milk daily and a small bowl of tofu or their equivalent would be beneficial. As osteoporosis is a major public health problem in Hong Kong and Asia, lifestyle advice should include recommendation of a higher consumption of soy.