I think the downside is that you don't just lose muscle in your legs and core, but rather you lose muscle mass all over. Yes, this is the expected result of calorie restriction but the issue is that when people lose a lot of weight without taking action to build and maintain muscle the amount of muscle loss they experience can cause other problems. Someone relying on a GLP-1 drug is often someone who isn't very active at all.
Well, you lose weight all over. You lose fat in your arms and your shoulders don't need to be quite as strong. You lose weight on your face and your neck muscles don't need to be quite as strong. You lose more in your legs, but you're supposed to lose muscle mass all over.
> Someone relying on a GLP-1 drug is often someone who isn't very active at all.
Sure, but that's a completely separate issue. It doesn't have anything to do with weight loss. Being in good strong physical shape is great, but nobody should expect weight loss to magically result in strength. That's like thinking you can stop going to the gym but won't lose any of the muscle you'd previously built up. It's got nothing to do with weight loss though. It's got to do with the fact that you're not working out.
The problem is that fat, sick people lose a lot of weight and muscle mass and then become skinny and frail. It just puts you at risk of other medical issues. In older individuals this can cause decreased mobility and raise the risk of falls. Its well documented in medical literature, that's why people worry about it.
But my point is that this is no different from being skinny and frail in the first place. It has nothing to do with losing weight.
Yes, that puts you at risk. That's why you should exercise, even if it just means daily walks.
The point is, you're not winding up with too little muscle because you lost weight. If you're winding up with too little muscle, it's because you're not being physically active enough. If you're physically active, you won't lose the muscle that you still need even as you lose weight.
> The point is, you're not winding up with too little muscle because you lost weight
Imagine someone eating only candy and pastries, but because they eat so huge amounts, they actually get a half-decent amount of protein. Then they decrease portion size with the help of appetite suppresants.
If you were physically active enough and careful about your diet you likely wouldn't be on a GPL-1 drug. That's the point. People end up in bad shape for a lot of reasons, including injury. The search for a mechanism to burn fat without losing muscle is to help support people who are on GLP-1 drug because for whatever reason they were insufficiently active.
I was describing how you lose fat all over. And as part of overall fat reduction, you lose fat in your arms, because your arms are one part of all over.
