The subject is 'weight' not men. Weight change can be from body fat, muscle mass, or water. The formula is the same for men or women. To lose one pound of 'fat' a week requires a deficit of 3,500 calories in one week. That is the equivalent of 500 calories per day. That deficit can be from diet change (Less calories), exercise (Burn calories), or a combination. But, there is something to keep in mind. When you exercise you build muscle, thus gain weight. So, you may burn off fat while gaining muscle. It is not usually notable at first, but can become more notable as one becomes more fit. That is why for fat loss it is recommended to be as concerned with body fat percent lowered as much as weight loss.