I want to regain my fit body.
Make sure you are getting enough protein from white meats/fish/eggs and egg whites/beans and legumes and higher fat proteins like nuts. You can add some servings of whole grain carbohydrates and also create "protein smoothies" with protein powder as the base.
Adding weight training should also help you to build some muscle mass.
You should also find out what your target BMI is - google a BMI chart and find the weight that for your height puts you at a BMI of about 21-23.