Don't worry. I don't think they'll expect you to lose too much weight in short time. You can always benefit from exercises and diets like excluding roti/bread, oils and fats. Use vegetables and fruits only. Also boiled chickpeas are good for energy.
Have coffee (without sugar and milk but you can use skim milk) half hour before workout. For breakfast soak chickpea at night and boil and eat in the morning. If you feel hungry, have some fruits after few hours.