How do you know if you're losing water weight?

As far as I remmember, the first weight loss is water loss, then you need a good diet not to lose muscle m but flab. Just avoid eating just vegetables and fruits, you need calories to get you through the day. Eat fresh chicken fried on olive oil or baked, red meat, tuna is fantastic, just without vegetable oil. Avoid all kinds of sweets (hidrogenated vegetable oil and glycose syrup are the reasons), dont drink soda and eat alot of fiber (oat meal with sugar free apple sause and cinnamon) and u will lose real weight. Also start jogging instead of walking a dog, u need exercise, i doubt the dog does too :) oh, and also drink about 3 liters of water per day.