Question: how much weight will you lose if you only eat 1000 calories a day?
Answer: Because 3,500 calories equals about 1 pound (0.45 kilogram) of fat, it's estimated that you need to burn about 3,500 calories to lose 1 pound. So, in general, if you cut about 500 to 1,000 calories a day from your typical diet, you'd lose about 1 to 2 pounds a week.