Depends on your height. Check your BMI from the health calculators to get to know what should be your ideal weight. Eat right with more fat products in the diet and you should be just fine in the next few months. I was around 53 kg at 5'9" till i was 25 years of age. Them by 28-29, I just started gaining weight and now I am worried about being over-weight if not obese.