Hi Alex M,I appreciate your desire to maintain a healthy body weight, but I believe you are over thinking this just a bit. Based on IBW and BMI you are at a healthy body weight. The IBW for a woman who is 5'9" is 145 pounds +/- 10%, which makes the healthy weight range between 130.5 - 159.5 pounds. The IBW for a man who is 5'9" is 160 pounds +/- 10%, making the weight range between 144 - 176 pounds. Based on those measurements, your weight is in the healthy range for your height. A BMI of or slightly higher than 23 is within the normal range. So you are at a healthy weight based on BMI as well. I would focus on weighing and measuring yourself at the same time everyday rather than when during the day to weigh and measure yourself, this allows you to track trends. Your weight is naturally going to go up during the day due to food intake so I wouldn’t worry about that. Many people find it easiest to weight themselves first thing in the morning. Heather Reese, MS, RD