Furthermore, it is leptitox important not to set the bar too high. Research shows that a weight loss of 10-15 percent is realistic. Suppose you weigh 80 kilograms, then a weight loss of 8 to 12 kilos is realistic to be able to maintain without falling back or becoming even heavier. What is a healthy weight? You can use the Body Mass Index to calculate whether you have a healthy weight. A healthy weight means that your BMI is between 18.5 and 24.9.