Hello.taking only bottled fruit juice is never good for health, so prefer to eat fresh clean fruits as it will be rich in fibres also. Avoid drinking alcohol,coffee and tea because as you have mentioned that you are a person with busy life,stress due to that along with this things can cause gastritis. Avoid smoked meats, fast foods and junk foods. If you are a non vegetarian you can prefer skinned out boiled chicken 1-2 pieces twice a week, fish curry as it is rich in protein and vitamins, eat fresh raw sprouts everyday in the morning, include berries snd nuts in your diet.your morning diet should include egg white as it is rich in proteins and a glass of milk,include green leafy vegetables in your diet.prefer brown rice,oats, soya beans instead of roti.prefer buttermilk,ragi gunji instead of soft drinks.if possible prefer olive oil or sunflower oil for cooking purposes.Drink plenty of water and stay hydrated. Do daily brisk walking, jogging for 20-30mins.yoga and meditation.if possible go for a trekking on a regular basis which will help you in developing stamina.if you are not satisfied kindly consult a dietician