According to the trust, they are officially counted as a vegetable, following advice from the Department of Health. But they should not be served to pupils every day.
Perhaps the trust should be more worried about beans of a different variety. A school in south-west China recently suffered a mass outbreak of poisoning after catering staff under-cooked kidney beans.
Luckily the incident was not fatal, although local officials said it caused 81 students to be sick and 167 were sent to hospital suffering from mass hysteria.
The poisoning at Zhuyuan Township High School may have occurred because kidney beans contain lectins - toxic agents that can cause diarrhoea if the beans are not heated properly.