hi,
Thank you for the query and I understand your concerns. Well considering your height and age i would say that your ideal weight is expected to be somewhere between 68-75 kg . Since you say your weight is as much as your dad's then i think that one of the reason for looking bulky is the weight itself. Other reasons might be fat concentration in the body , bone weight or your body composition.
In your case, genetics could also be a reason for
overweight considering your dad being heavy too.
Your twin brother might not be on a heavier side as guys have a higher metabolic rate compared to girls, hence they tend to burn fat more faster than women.
You need to be worried about your weight issues if its causing you health problems and if its coming in the way of your routine activities.
To be on a safer side, get a
thyroid profile and hormone levels test done . You can review with me once you get the results. Meanwhile i suggest you to try the following for 3-6 months-
1. cut low on fats, eat more of fibre-rich food including atleast 4-5 litres of water per day.
2. get involved in some kind of physical activity to burn the consumed calories.
3. keep a target weight to be lost for every week and keep yourself motivated.
Get the above mentioned blood tests done and start working on the lifestyle changes. Get back to me with the reports as soon as possible.
wish you good health .