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Hi. There's no such diet for the double chin and face fat. You need to reduce your body weight for that and also, have to do some exercises for both.

Hi, you will have to eat Potassium rich foods such as Banana (not in excess), Coconut water, moderate amount of Potato, Low sodium salt (easily available in market), rock salt, tomato,  spinach, soybean and other pulses. These are rich in Potassium and would fulfil your body's exact requirements as per RDA. High Protein and high fiber foods should also be there. Apart from that you will have to drink 15-20 glasses of water in a day. This would be helpful to flush unhealthy excess water from the body. Please remember Potassium rich foods should not be taken in excess amount. For actual amount and calculations of requirements of Potassium, please contact your Dietitian, he or she would be able to adjust the amount of these foods. Cardio exercises are also found beneficial such as running, cycling, dancing etc. Certainly you will get good results.

Along with the workout, proper diet need to be followed. You can consult directly through Practo for customised diet plan

Eat papaya daily and do bhujangasana daily. Try this for one week and if you not get benefitted,take my appointment