In morning i weighed 90.7kg, after medium sized lunch i weighed 92.2kg, is this normal?

Yes.: Weight fluctuates throughout the day. Weight increases due to the food and liquid you take in (water is heavier than most people realize!). Weight is lost through sweating, breathing (your body water evaporation is slight, but it's there), urination, defecation, and the burning of fat and other fuels both during workouts and in the general course of your day. Up to 5lbs/2kg is normal.