Okay so you weight is 100kg or 220lb? for your height 180cm which is extremely overweight. I think you need a diet plan... Stay away from fast foods (all trans-fat food) Soda any food with high sugars. No Junk Food!! no chips which contain too much sodium which is bad for your health. try eat food with higher fibers, protein, eat brown rice.., wheat bread, yogurt, GO to the gym and lift some dumb bell.. i can't tell you what is light or heavy until you lift it. Everyone's strength is different.