The reason the percentage method is better is because using an absolute number
like 500, 750 or 1000 calories as a deficit instead of a percentage deficit might drop your
calories into the danger zone. For example, if you are a male with a 3500 calorie
maintenance level, a 750 calorie deficit to 2750 calories per day is only a 21% drop (a
small, safe and acceptable deficit.) However, if you are a female with an 1800 calorie per
day maintenance level and you cut your calories by 750 per day to 1050 calories, that is a
41% cut. Using the percentage method is more individualized.