The definition of injustice is something that is not fair or just. An example of injustice is when an innocent person is sent to jail for a crime he did not commit. the quality of being unjust or unfair; lack of justice. an unjust act; injury.
That means that you don't exercise on a regular basis. The calorie calculator may say that you need to eat 1,200 calories per day to lose weight. But you don't think that you can cut enough food from your diet to reach that number. That's okay.
Depends how many calories you are eating! To lose one pound, you must burn off 3,500 more calories than you eat. So, if you eat 2,000 calories per day for 7 days, that's 14,000 calories per week. To lose a pound, you must do enough exercise to burn 17,500 calories per week.