For a
weight loss first you have to analyse what you are right now. A low fat low cal diet program will help you to loose weight.
1.Split your meal to 3 main meals and 2 snacks+liters of water min in a day.
2. substitute complex carbs like oats,quinoa,barley,wheat instead of white rava,white bread
3. variety of vegetables and fruits
4. Avoid high cal veggies and fruits like potato,yam,pineapple,mango,sapotta
5. Limit oil and salt intake
6. Avoid sugar
7. Physical act min 30-45 per day.
To regain your lost weight in your back area, there are specific exercises and yogasanas which you can contact a physical trainer or a yoga instructor