Hi doctor, i am aged 25 with over weight of extra 30kgs. trying all various diet from 3yrs but no result. please advice me on this?

Nutrient dense foods: Eat foods that are nutrient dense (like meat, fish, poultry, eggs, cheese, low starch vegatables and water) avoid foods that are not nutrient dense (like starches and sugars, including fruit) nutrient dense foods will increase your basal metabolic rate. On the other hand, starches and sugars impair thyroid metabolism via affects on your liver (which helps activate thyroid hormone).

Balance: After ruling out and normalizing metabolic factors related to weight gain (thyroid, Insulin resistance, etc.) creating a calorie imbalance towards burning more calories than you take in will generate weight loss. It takes approximately 8000kcal to burn 1 kg. The regulation of weight is very complex hormonally. Many have proposed a hormonal basis for various diets but the data is limited.

Calories in n out: See the excellent answers on "weight loss". You basically need to burn more calories than you take in. Increase your exercise, choose healthier, less-caloric foods and drinks. The nice thing is that if u build more muscle you will even burn more calories while you sleep! and don't focus too much on weight. Focus more on pants-size, etc. Muscle weighs more than fat but that's ok--its good wt.