Generally, the dietary guidelines for Americans they say that adult women need 1,600 to 2,400 calories daily, and adult men 2,000 to 3,000 calories per day. However, the total number of calories a person needs varies daily based on a number of factors including a person's age, gender, height, weight, and level of physical activity. Consult a physician if you are overweight to determine the course to take, which will likely include modifications to daily dietary habits and a regular exercise program. However, there may be underlying health conditions that may require additional treatment, such as high blood pressure, high cholesterol, and high blood sugar. Within each age and gender category, the low limit is for sedentary people, while the high limit applies to active people.