@eris @scathach there are specific needed nutrients that support hair growth and losing weight at a reasonable pace, especially if you boost cruciferous veggies and reduce starch, will actually improve your hair because you're getting more vitamins and less empty calories. losing fat is just one benefit of eliminating carbs.
i've been on a variety of diets, including keto, and done 2 separate 6 day fasts, and it didn't cause any hair loss. but maybe your experience will be different. eat whatever you want, but you're misinformed.