Heyyy, I was being a little sarcastic. But seriously, If you want to lose weight, the number one factor to consider is how active you are???? If you weigh , lets say, 200 lbs and eat 2000 calories a day, normal for a man, and dont exercise, then you will NEVER lose the weight. But, if you walk 4 miles/day 4-5 times per week, you will burn 2000-2500 calories a week or 10000 a month for a 3 lb weight loss. And also increase your metabolic rate. Diets DO NOT WORK!!!!
I know overweight people who drink a ton of water and dont lose the weight. Again, the only way to lose the weight is to burn MORE than you take in -- exercise.
About weighing yourself. If you have a monthly goal, then weekly weighings are fine. But if your goal is losing weight for the year, monthly weighings are best.
As for myself, I am 69" and weigh 147lbs. I eat about 2500 cal/day, run 15 mis/week, walk 25 mis/week and avoid alcohol [pure sugar] completely. My BMI is 21.4