In order to shed one pound you must burn 3500 calories. Try having her eat 1200 calories a day--you need 1800 calories a day to maintain your weight.
1200 cals is the absolute minimum threshold you should never go below, but that is by NO MEANS good, healthy dieting advice. You might lose weight, but you'll lose mostly water and muscle, eventually slowing your metabolism. The other problem is that people with a weight issue will lose their freaking minds trying to eat 1200 cals/day. Eventually they'll just snap, eat a 5kg bag of peanut M&Ms (or whatever), and say to hell with this dieting thing!
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