thank you for reply...very informative:)
100g of lemon is 29 cal (121 kJ) while 100g of grapefruit is 32 cal (134 kJ). MedHelp has a great food tracker that can help you determine and keep track of your food servings, calorie counts, etc.. for any food/meals that you're looking for. I say give that a try. If you can't find it there, there are other helpful websites out there that can give you pretty accurate food calorie count as well, such as calorieking.com.