Perhaps a more effective way to adress your question is to recognize that losing weight is based on energy balance, calories in versus calories out. The evidence suggests that a negative energy balance of approximately 3,500 kilocalories will lead to a weight loss of a pound. This simply means that we need to expend 3,500 more kilocalories than we consume in order to lose a pound.
That’s why I encourage clients to keep a detailed 3-day dietary record to determine if there may be ways to eliminate unnecessary caloric intake. But keep in mind that adequate intake is essential in order to give the body adequate energy reserves to support the vigorous exercise that is the key to effective weight loss and long-term weight management.