"Three phases" refers to the menstrual period, pregnancy and lactation of white-collar women. During menstruation, iron-containing food should be supplemented to supplement the iron lost during menstruation. Eat more pork liver, lean meat, fish, seaweed, kelp and so on. During pregnancy and lactation, we should ensure calories and high-quality protein. The daily calories in the third trimester will increase by 200 kilocalories, 25 grams in protein, 800 kilocalories in lactation and 25 grams in protein. At the same time, it is necessary to supplement enough minerals and vitamins, and supplement 10 mg of iron every day. Pay attention to the intake of vitamin A, vitamin B 1, vitamin C and vitamin D.