Is there any information on what is considered a healthy (and sustainable) weight and body fat % loss? How many pounds/bf% for each week can I compare my results against so that I know I'm making good progress and that the loss I'm experiencing is sustainable and long term.
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Your fat storage can only release 69 kcal/kg per day from your fat mass to be consume as energy. If you use up more energy then that it will be taken from somewhere else. Probably muscle mass.
I will make the assumption that the cell itself is not consumed in the process, therefor the only weight contribution is lipids and water. Water mass is far less and pretty constant in comparison to fat. The energy content of fat in adipose tissue is approximatly 9000[kcal/kg]*80% = 7200 kcal/kg.
What this means is that the fat you have on your body dictates how much caloric deficit you can be in before you start losing fat free mass as it is also shown here.
If you weight somewhere around 130kg, with 73kg lean mass and 57kg fat mass. You can use almost 69 * 57 ~= 4000 kcal/day from your fat storage as energy without making too much sacrifice on muscle mass. That can be up to 7 [days] * 4000[kcal/day] / 7000[kcal/kg] = 4kg of fatloss per week. Almost 9 lbs!
As you approach 5-6% body fat, your estimated maximum loss of body fat approaches 1 lbs.
Conclusion So what we see is that 2-3lbs/week is a good estimate for a normal person to achieve a goal for the duration of a normal diet plan. As you get leaner the rule of thumb is getting harder to keep without starting to lose lean mass. Also if you are obese there are no problems to lose more then the 2-3lbs/week.
These calculation are estimates and should be seen as optimal release, this do not take metabolic adaptation and and other effects like hormonal issues into acount. What it shows is how much you can be in caloric deficit before you start losing muscle mass.
This is different for everyone and every situation. What might be considered a healthy "weight loss rate" for someone in a certain situation can be totally different for someone else or in another situation.
Providing your body with the right nutrients and get the right amount of exercise will automatically result in your ideal "weight loss rate".
From experience I found that loosing 5 lbs per week is normal for most people if you adjust you lifestyle and eating habits.
Try this: Consume more water rich foods (vegetables and fruit) and limit your intake of sugar and fast carbohydrates.
I'd recommend you to do some research on healthy nutrition an exercise and see how your body is reacting to it. More than measuring your success by your weight loss, I would suggest you to measure your success by how you feel.