给出一个英文文本，回答以下问题：“文本中提到的主题是什么？”



文本：“In recent years, there has been a surge in the popularity of plant-based diets. Many people are turning to veganism or vegetarianism to improve their health or reduce their carbon footprint. Some studies suggest that a plant-based diet may provide health benefits, such as reducing the risk of heart disease and certain cancers. However, others argue that a plant-based diet may not provide all the necessary nutrients and may require careful planning to ensure proper nutrition.”
主题是植物性饮食的流行和可能带来的优缺点以及必须注意的营养问题。