Goal weight and ideal weight, how to define it under GLP1?

[BLASIUS]

Hi all,

I'd like to know how you guys under GLP1 medications are defining the Goal Weight compared to the Ideal Weight.

I discussed my current status in this thread:

[archived internal link]

Height 180cm

CW 104 Kg

IW 71,3 Kg (according to my body composition measurement scale)

GW ??

If I had to consider GW=IW, I need to lose additional 33 Kg (starting weight was 120kg July 2025), but this is a huge amount in my opinion, so what to consider?

It would be better to accept a compromise (let us say 80 Kg) or to persevere until IW?

Please let me know your idea

 

[Abrakebabra]

Goal weight is whatever you decide it is. There's no formula and "ideal weight". The better question is what you're trying to achieve.

 

[lessthanhalf]

I agree that it depends on what you want. And quite a lot of other factors.

If you are fairly muscular and doing weights, it is going to be a fair bit higher than if you are inactive or not doing much physical work.

There is a pretty big psychological benefit of getting into the normal weight range, but in a lot of ways aiming for a BMI in the 25-30 range - like 80kg, actually makes more sense in terms of being more likely to be sustainable in the long term without a substantially low calorie intake per day. As once large weight losses have happened energy expenditure will drop and probably stay low long term, requiring less than average for weight and age and activity level number of calories per day to maintain the loss. This does seem to vary a lot , but definitely seems to be much more of an issue in those with severe obesity who lose a lot of weight. A few extra kilos are not going to make a huge difference, but as you get closer to normal weight , loss gets harder as your body tries to hang on to every fat cell it can.

After losing 70 kg from 145 to 75kg my energy expenditure dropped in half, and stayed there so that calorie intake of 1600-1900 kcal/day was required to lose the weight , and was required to stay there, and only adding in tirz/reta got me to lose any further weight to 65kg, presumably from minor drops in calories in per day. 1-200 kcal/day is required to lose weight at 5-10kg/y which is pretty hard to accurately measure.

In terms of health , that 20kg you have lost is the most important part in terms of reducing long term risks, losing more reduces risks further but not putting weight back on is the most important part, in terms of getting risks out of the extreme range, so moderate expectations are not a terrible idea, and once you get anywhere near the normal weight range fitness is far more important than fatness in terms of health risks. So sustainability of the weight loss is super important, and it means if it takes constant effort to keep calorie intake at a reasonable level , the odds of long term maintenance get worse. Which is a good reason to stay on GLPs after weight loss for maintenance, but also might mean picking a higher target to make maintaining it less difficult. But being happy with what you do achieve is important whether it is at your goal weight or not. There is no guarantee of losing 50kg with any current GLP drugs , and no guarantee even with GLP stacking if you respond less than average to them.

Despite seeing the logic in this, I have got to a BMI of 23 with tirz15mg/reta5mg/cagri0.5mg/hgh0.8iu, and I likely need all of them to have any chance of staying there.

 

[ultima thule]

For me there's 2 main factors. BMI, which is actually less important, but still gives some picture. The other one is a BF %. My goal is 12-15%...starting from 29% now, so believe it's a long way, but possible to achieve in a the next few months. 2 years ago, when I achieved my required BMI and 19% BF, with no any medications it has taken me a 16 months roughly. And I was starting from 36% BF. Hence that experience tells me 2 things. I can do it, when supported with Reta, and on the other hand BMI is not the most crucial factor.

 

[BLASIUS]

Goal weight is whatever you decide it is. There's no formula and "ideal weight". The better question is what you're trying to achieve.

Yes this is just a definition of the terms, but somehow any of us in this GLP1 journey has to define the Goal Weight, and somehow has to find a rule to determine it.

Of course you can just decide to stay on GLP1 for some time (e.g. 1 year), without any Goal Weight to reach and observe the progress of your results, but I don't think it is a valid approach,.

I prefer to have a Goal, it helps me in keep my focus and change my habits if it is the case.

When I began the GLP1 journey I fixed my GW in 80Kg (around 40Kg loss) in 2 years.

After 9 months I am under my expectation, in the last 2 months, the weight loss hasn't been enough, so I am struggling in order to find some way to give it a change

 

[BLASIUS]

I agree that it depends on what you want. And quite a lot of other factors.

If you are fairly muscular and doing weights, it is going to be a fair bit higher than if you are inactive or not doing much physical work.

There is a pretty big psychological benefit of getting into the normal weight range, but in a lot of ways aiming for a BMI in the 25-30 range - like 80kg, actually makes more sense in terms of being more likely to be sustainable in the long term without a substantially low calorie intake per day. As once large weight losses have happened energy expenditure will drop and probably stay low long term, requiring less than average for weight and age and activity level number of calories per day to maintain the loss. This does seem to vary a lot , but definitely seems to be much more of an issue in those with severe obesity who lose a lot of weight. A few extra kilos are not going to make a huge difference, but as you get closer to normal weight , loss gets harder as your body tries to hang on to every fat cell it can.

After losing 70 kg from 145 to 75kg my energy expenditure dropped in half, and stayed there so that calorie intake of 1600-1900 kcal/day was required to lose the weight , and was required to stay there, and only adding in tirz/reta got me to lose any further weight to 65kg, presumably from minor drops in calories in per day. 1-200 kcal/day is required to lose weight at 5-10kg/y which is pretty hard to accurately measure.

In terms of health , that 20kg you have lost is the most important part in terms of reducing long term risks, losing more reduces risks further but not putting weight back on is the most important part, in terms of getting risks out of the extreme range, so moderate expectations are not a terrible idea, and once you get anywhere near the normal weight range fitness is far more important than fatness in terms of health risks. So sustainability of the weight loss is super important, and it means if it takes constant effort to keep calorie intake at a reasonable level , the odds of long term maintenance get worse. Which is a good reason to stay on GLPs after weight loss for maintenance, but also might mean picking a higher target to make maintaining it less difficult. But being happy with what you do achieve is important whether it is at your goal weight or not. There is no guarantee of losing 50kg with any current GLP drugs , and no guarantee even with GLP stacking if you respond less than average to them.

Despite seeing the logic in this, I have got to a BMI of 23 with tirz15mg/reta5mg/cagri0.5mg/hgh0.8iu, and I likely need all of them to have any chance of staying there.

My congratulations,

when you will reach your final GW you will need to change your nickname accordingly, maybe "Almost1/3" will be better

 

[BLASIUS]

For me there's 2 main factors. BMI, which is actually less important, but still gives some picture. The other one is a BF %. My goal is 12-15%...starting from 29% now, so believe it's a long way, but possible to achieve in a the next few months. 2 years ago, when I achieved my required BMI and 19% BF, with no any medications it has taken me a 16 months roughly. And I was starting from 36% BF. Hence that experience tells me 2 things. I can do it, when supported with Reta, and on the other hand BMI is not the most crucial factor.

Yes to aim to a specific BF% will be better than to a specific BMI, I know BMI is very approximated value.

My current BF% is 25.3%, what has to be my weight if I would have 15% BF?

Is it 71.3 Kg as my bioimpedance scale is telling?

 

[ultima thule]

Yes to aim to a specific BF% will be better than to a specific BMI, I know BMI is very approximated value.

My current BF% is 25.3%, what has to be my weight if I would have 15% BF?

Is it 71.3 Kg as my bioimpedance scale is telling?

It depends on a fat/muscle ratio. Some fella with 50% BF may have same BMI as the bodybuilder with 7%...fat is lighter, than muscle tissue...losing fat and building muscles simultaneously is a golden standard.

 

[lessthanhalf]

Thanks, when I made the account I was almost at half my start weight.

If your scales are accurate, and they are often not that accurate or even close, then if you are currently 25% bf then 15% bf is about 10kg lower assuming lean mass does not change. Not perfectly accurate, but ballpark correct, which would put you at 15% at 94kg or maybe 90-92kg if there was some lean mass loss. 15% is pretty low fat, so those scales are only accurate if you are pretty muscular. My calculation is pretty simplistic, but it makes more logical sense that what your scales are saying. The only accurate body fat measurement is dexa scan or MRI. You can use some online calculators based on measurements of waist and neck and arm circumference ( i think )

I am probably around the 25% mark but am not doing a lot of exercise.

 

[BLASIUS]

It depends on a fat/muscle ratio. Some fella with 50% BF may have same BMI as the bodybuilder with 7%...fat is lighter, than muscle tissue...losing fat and building muscles simultaneously is a golden standard.

If my bioimpedance scale is telling the truth I have 26,5 Kg (25,3% BF) of fat in my body, if my Ideal Weight was 71,3Kg as for my scale I had to lose additional 34 Kg, this means that I haven't to lose only fat, I have to lose lean mass as well.

So, is my scale kidding me telling a nonsense IW, or I am missing something?

 

[testyonenow42]

My starting goal was about 10-15 lbs above what I was in my 30's. I wanted something realistic and didn't require over the top dedication as my goal is to be able to do what I want as I get older. I am now 15lbs below that goal and likely the lightest I have been since middle school (maybe HS freshman). I feel great and I am still slowly losing. I think I will drop another 10-15lbs before I go into maintenance, but my goal now is fat loss. I dont have a specific BF goal but i'll know it when that extra fat layer around my midsection shrinks. I've also been strength training the entire time to maintain muscle.

 

[TruckingUK]

I'm currently struggling with this concept myself and seem unable to come up with a goal weight/target to aim for.

Currently at 104.3kg having started 114.8kg in the middle of march

 

[lessthanhalf]

A BMI of 28 ish at 90kg and 1.8m is not an issue if body fat is 15%. It is somewhat debatable if high BMI is a cardiovascular risk factor at low body fat and high muscle levels, but realistically , extra muscle is not metabolically unhealthy the way extra fat is. It would almost certainly be less healthy to lose an extra 17kg of lean muscle and presumably some fat to get to 73kg and a BMI of 22. 15% body fat is pretty slim, and way below average, the only people aiming to get lower are usually pretty serious bodybuilders, and their methods are not usually healthy anyway.

So assuming your scales are telling the truth aiming for less than 90kg with a body fat of 15% would be pretty extreme. Waist circumference can give you some indication of visceral fat which is a fairly good indicator of metabolic health.

 

[5byfive]

I would recommend a Dexa scan; its the only way you are really going to know what is going on. Having a good measure of your body composition is really ideal when making a decision this important.

The only downside is there are some bad machines out there. I got a scan from a small women's health clinic and the results were pretty off. If you have a university near you with an exercise science program, that is the best bet. Personally, I would make sure they are using a GE machine, they seem to be at the hugher end. Using a scale is next to useless. They are not good at even tracking changes over time let alone giving you an accurate reading.

What is a good goal? For a man, anywhere around 20% is pretty healthy, 15% is really good, and most people will have a hard time maintaining anything less than 12%. For a woman, those numbers are about 10% hugher.

 

[Grogu]

I, too, was struggling with determining a goal weight based on conventional guidelines, so I asked my primary care physician and she looked at me and said I looked good. Seriously. That was her medical opinion. Mind you, I was probably 250lbs at the time.

Being 6'4" male, the BMI calculations say my "normal" weight should be 152-205. Metlife tables say I should weight 181-207.

So, I had a Dexa scan a couple of weeks ago and that says I'm 223 and 23% body fat and my "goal" mass is 218lbs and 20% body fat. I'm supposed to do this by dropping to 218 while gaining 3lbs of muscle. I'm not sure if those maths are correct.

I feel the Dexa scan at least provides some direction where BMI and weight charts are not really good measures. My doctor's "you look good" being the least precise.

 

[BLASIUS]

I'm currently struggling with this concept myself and seem unable to come up with a goal weight/target to aim for.

Currently at 104.3kg having started 114.8kg in the middle of march

We are in the same boat

 

[BLASIUS]

A BMI of 28 ish at 90kg and 1.8m is not an issue if body fat is 15%. It is somewhat debatable if high BMI is a cardiovascular risk factor at low body fat and high muscle levels, but realistically , extra muscle is not metabolically unhealthy the way extra fat is. It would almost certainly be less healthy to lose an extra 17kg of lean muscle and presumably some fat to get to 73kg and a BMI of 22. 15% body fat is pretty slim, and way below average, the only people aiming to get lower are usually pretty serious bodybuilders, and their methods are not usually healthy anyway.

So assuming your scales are telling the truth aiming for less than 90kg with a body fat of 15% would be pretty extreme. Waist circumference can give you some indication of visceral fat which is a fairly good indicator of metabolic health.

So do you think my initial GW (80kg) was too low?

 

[Pin&Play]

If my bioimpedance scale is telling the truth I have 26,5 Kg (25,3% BF) of fat in my body, if my Ideal Weight was 71,3Kg as for my scale I had to lose additional 34 Kg, this means that I haven't to lose only fat, I have to lose lean mass as well.

So, is my scale kidding me telling a nonsense IW, or I am missing something?

Scales are inaccurate. I'm 172cm / 77kg and my bf is likely around 19-20% now, it was 25% when I was weighting 82kg (measured by DEXA while according to Inbody I was 20%).

You might be closer to 30%. You don't have to know if you don't care, and just use your scale to track progress, even if the number is not correct, but if you want a real number then DEXA is your best bet.

Just give yourself multiple goals, the first could be reaching 18-20% bf, and calculate the weight based on that.

If I only followed BMI I'd have to aim at 65kg which is very low for me as I have a good amount of muscle