No, youi still need some fat in your diet. There is not enough in omega 3 pills for example as its more concerntrated so the oil itslef is actually very reduced in quantity.
Try to stick to non heated vegetable based oils such as oilive oil and that from food. Animal fats tend to carry saturated fat which is not required for the body but is fine to eat in small quantities. Once you heat vegetable oils they partially become saturated fats.
Fats help with appetite control, help your joints to function and repair and help with overall health. Your body fat is not the same as oils and fats you eat. You will not put on fat as a direct result of eating them, the only way you will put on fat/weight is to consume more calories then your body needs. Count and keep tabs on your calories, you'll be fine.