Is it safe to reduce 1 kg per day..if so which diet should i follow..i m 29 year old..my weight 58kg..saggy belly post pregnancy..my height 153cm?

Go slow: The usual target for weight loss is one pound per week. A crash effort is more likely to fail and cause other health problems. Reduce your food intake by half, drink enough water so your urine is mostly colorless, exercise 30 minutes/day. If the rate of weight loss is less than one pound/week, reduce your food intake further. Get HPV and Covid vaccines. Wish you good health!