This can be done by reducing the daily intake by 500 calories per day (it will provide a deficit of 3500 calories per week).
To lose 2 pounds per week, a deficit of 1000 calories per day is required.
Chronic illness can also cause you to lose weight.
As a matter of fact, I know of a guy who, understanding that he was prone to a certain feverish relapse every other month, he would eat himself to substantial fat prior to that. Months later, when he fell ill, he would lose all that weight in a couple of days. Cute idea, but don’t try it at home.
Some people rely on illness to help them lose weight. While this is fair enough the first time around, you shouldn’t make a habit of it.
Getting used to such could result in some kind of ‘cry-wolf’ syndrome in which you might not recover from the illness soon enough. In the end, you lose.
