I'm in my 34weeks now, during my latest scan (few days ago), was told my baby was weighing less than 2kg. Is it ok? Or do I have to eat something for the baby to absorb and gain as much weigh as possible for the remaining 5 weeks?

Ultrasound scan is not a good indicator in estimating the size of your baby. It's accuracy is only about 40%. Eating a balance diet and focus on digestion is important. Do talk to your baby, rubbing of belly all can help baby grow. You can consider seeking help from TCM physician, Ayurveda Doctor or Naturopathy Doctor for advice on nutrition.