can i lose weight by eating salads everyday and ride bike?

[yesenia s]

i weight 120 pounds and 5 feet and 4 in tall.. i think that i gain weight this couple of months because the last time i checked to go to the doctor i weighted 109 pounds. i feel fatter my clouthes dont feet me.....can i lose weight by eating salads and doing some exserse at home or ride bike...my mom doesnt let me go outside alot so i cant do much exsersise outside....can u guys give me a eating plan,,,,thenx