How i maintain my diet chart to keep myself slim and trim?

I am a married, working woman.I have no child.I recently got married.I want advice from a good health instructor.I want to know that how i make my diet plan to keep myself slim.I am doing yoga asanas frequently.But due to lack of good diet I don't get fruitful result.I don't know what and how many times I eat to keep myself healthy and slim.please give me diet chart.I am vegetarian.I am fond of eating.I get hungry every two to three hour.I eat three times in a day.At 10 A.M then I eat paratha, dal,curd and vegetables.At 3 p.m I eat rice dal and vegetables and again at night I eat roti and sabji.Recently I got little fatness and my skin is not shining.I fond of sweets.I want to know that eating sweets increase my weight? please help me?