what are you doing man
That's not how this conversation thing works. We talk about you and you're interests. Now tell me more about your swimming. 
yes better the swimming in tell
Swimming is good for weight loss and also builds strength and endurance.
yes what is health good
Speaking of health, fast food is very bad for good health. It lowers the quality of a person's diet and leads to childhood obesity. 
yes old person swimming is good health 
Swimming is one of the best work outs for the elderly thanks to it's inherently safe nature. It's a low impact work out with a low risk of injury.
yes together is always okay in our life
Eating fast food before swimming isn't a good idea though. It can lead to stomach cramps.