My weight is 81kg, what should i do control it, as it can cause me to face many diseases?

First see Dr., then: Helpful weight loss diets have natural foods that take time to chew but contain few calories. Examples include carrots, celery, and iceberg lettuce (little/no salad dressing). When shopping for fruits, buy small ones no bigger than a tennis ball, because fruits have sugar. Drinks without calories include water and green tea. A calorie is a calorie, but surely avoid sugar & simple starch calories.