How quickly do you lose skeletal muscle mass?

LesIckaBod

I'm hoping this question is purely theoretical, but my Fitbit Aria scale is showing 1.2% BF increase with 11 lbs weight loss in the last 30 days.

So, without addressing my case specifically, does any one know the basic research that answers this question?

Keto_Vampire

Bone Mineral Density is an extremely slow paced process...normally done on an every 2 year basis. I don't think your standard weight scale is going to be very accurate...needs a DEXA (assuming you are an adult, not pediatric age)

LesIckaBod

Keto_Vampire wrote: »

Bone Mineral Density is an extremely slow paced process...normally done on an every 2 year basis. I don't think your standard weight scale is going to be very accurate...needs a DEXA (assuming you are an adult, not pediatric age)

Skeletal muscle mass is different from skeletal mass, isn't it?

I had done three InBody analyses that showed gains in SMM with loss in weight. Across that same time period, my Aria showed 5.1% BF loss with 25 lbs weight loss. I figured the Aria wasn't giving me accurate BF%, but I thought I could trust the downward trend. The recent BF% gain on the Aria makes me a little concerned. It will be a few weeks before I'm able to do the InBody scan again, so I was curious what the many knowledgeable folks here would have to say about this.

Keto_Vampire

My bad (missed one word); still would not be concerned if solely looking @ aria for BF%. How does the mirror interpret your body composition changes? Or more importantly waist:hip:shoulder ratio changes

LesIckaBod

Keto_Vampire wrote: »

My bad (missed one word); still would not be concerned if solely looking @ aria for BF%. How does the mirror interpret your body composition changes? Or more importantly waist:hip:shoulder ratio changes

I feel like body composition is improving. I haven't measured myself, but I need a new belt and shirts that I couldn't get buttoned fully are now saggy and loose around me, and there's a clear indent at the waist, so I think the overall ratio is progressing in the right direct. On the other hand, I'm skeptical of my ability to accurately observe and assess myself, which is why I like the InBody analysis.

I guess I'll see in a couple weeks.

Tic78

If you aren’t so good at observing and assessing yourself then another reasonable guide would be to know that you are maintaining your strength in a cut or if new to lifting perhaps increasing your strength in lifts initially. Also not losing more than 1% of your bodyweight per week after the initial water weight drop is another indicator that hopefully you are losing mainly fat. Some people can lose more than 1% per week but really that’s down to how much weight they have to lose.

While I don’t have any direct experience of the Fitbit scale BIA is likely the most unreliable way to track bodyfat. The results are general skewed. They can be heavily affected by water intake/food timing etc. I understand you are using them for more of a trend purpose but some of them can vary wildly if you step on them several times over the course of the day. Again no experience of the Fitbit scales but only bia scales I have ever found to be semi decent and even then still not great are Tanita scales. You should consider an app such as happy scale that gives you the average weight loss, it helps not be to disheartened by water weight fluctuations.

Anyway I’m sure you are doing great, I know how annoying it can be not having accurate data points to ensure your going in the right direction. Keep your strength up, stick to eating below your tdee and trust the process.

Good luck

LesIckaBod

Thanks to those of you who responded - I appreciate it, and I know I probably posted in this question in the wrong forum (sorry!).

I just got my most recent report on the InBody 570, which is BIA with a current through hands and feet. Over 130 days, weight is clearly down, BF% is trending down, and maybe I've been able to gain some muscle? I'm feeling good about this, and I'm happy to ignore the Aria's strange fluctuations.