Medically reviewed by Kayla Girgen, RD The average adult woman needs about 1,600-2,400 calories a day.A calorie deficit, in which you take in fewer calories than you burn, is necessary for weight loss ...

How many calories you eat a day depends on your physical activity level, age, and sex. If you want to lose weight you need to eat fewer calories than your body burns. If you want to gain weight, you ...