Intermittent fasting and keto

One of my friends does keto and IF and hasn't had a problem with her supply dropping from it (according to her) I kind of feel she likes to brag about how quick she is loosing the weight, etc.. and she credits these diets..but anyway.. I was wondering if anybody has experience with doing these diets during breastfeeding and what your results were? She does Keto and with the IF she stops consuming food about 7pm and doesnt eat again until 11am/noon the next day, does this work for weightloss after baby and still keeps supply good?