For most people, losing 50 pounds in two months while remaining healthy is not a realistic goal. By consuming fewer calories than are burned per day, it is healthy to lose up to two pounds per week for the average person, which would come out to roughly 16 to 20 pounds in two months.
Larger people, such as those over 250 pounds, can safely lose more weight per week. Those with diets high in sodium and starch can have a significant loss of up to 5 pounds in the first week by limiting intake of these two nutrients. This initial loss is mostly water weight from reducing fluid retention caused by salt and starch.
Eating 500 fewer calories than are burned per day results in about a pound lost each week; one pound is roughly 3500 calories. Alternatively, a person can exercise away 500 calories fewer than his base maintenance calorie level to lose a pound each week.
Instead of a fad diet, it is better to include healthy, non-processed foods as part of a lifestyle change. Large amounts of low-calorie vegetables fill the stomach, reducing the risk of overeating. Food journals are essential to tracking calories, since keeping a note of everything eaten provides a way to stay accountable.