What you want to ask is, can you lose weight for four months by consuming 300 kilocalories a day? Yes According to query 35, the health network shows. It consumes 300 kilocalories a day. If you eat properly, it will take 4 months to lose weight. Because one kilogram of fat is equal to 3500 kilocalories, you can achieve obvious slimming effect by losing 12 kg, so you can lose weight for 4 months with only 300 kilocalories a day. So 300 kilocalories a day can last for 4 months to lose weight.