What would be considered unexplained weightloss if you had cancer?

10lbs or > 5%: Unexplained weight with cancer is defined as unintentional weight loss exceeding 10 pounds (4.5 kilograms) or more, or weight loss of more than 5 percent of your body weight over a period of 6 to 12 months.

3500Cal/lb fat: Weight loss in spite of adecuate caloric intake and urine output for activity and basal metabolic rate expenditure. It takes 3500cal deficit to loose one pound of fat. Each 454cc of urine weights one pound.