Withings scale accuracy for TRENDS

Alatariel75

Question for people who may have done more research than I - I know that the bathroom scales that profess to tell you your muscle/fat/water breakdown are little more than a gimmick when it comes to a snapshot of your body composition, but are they any more accurate when it comes to tracking a trend long term?

Below is my Withings body comp graph for the last 6 months. Now it says I've lost a bit of muscle, and a lot of fat. But I know I've lost fast, and while I do exercise, I'm not lifting weights or doing a whole lot of resistence exercise, so I don't know if it is of any use to me in indicating whether I've lost more muscle mass than it seems to show.

I'm not overly fussed, not planning on getting a DEXA scan or anything, but I'm curious and I'd be interested in thoughts

AnnPT77

There are studies that looked at ratios of fat to lean mass lost in various weight loss scenarios. I don't have any of those at my fingertips or bookmarked, but it should be relatively easy to find some, or to find summaries/reviews from some of the better blog-y sources.

Examine.com, usually a decent source IMO, says this in one of their articles:

When you lose weight, some of it will be fat loss, and some proportion (usually around 25%) will be lean mass and/or muscle mass. It should be noted that lean mass loss is not always muscle mass loss per se, as lean mass comprises muscle, but also bone, connective tissue, organs, and body water content. The goal of most fat loss programs is to improve body composition — in other words, to increase the body’s proportion of lean mass to fat mass.

That's from an article about GLP-1 drugs, but a general (not GLP-1 specific) comment. This is the link, but I don't know whether it's subscriber-only content:

https://examine.com/faq/will-weight-loss-drugs-cause-me-to-lose-muscle/

Of course there would be variation around the mean in the studies, anyway, so your n=1 could vary. You look to be around that neighborhood in your Withings stats, and not exercising might drive the individual results to a slightly higher proportion of lean loss alongside fat loss. There's also that relevant comment about lean mass vs. muscle mass, and I'm not sure what components Withings estimates.

For lean mass specifically (not just the muscle mass), I'd say we want to lose some of that - I'm thinking I don't need the same total blood volume I did, for example, when there was nearly 40% more of me.

Alatariel75

Thanks Ann! I agree, I would totally expect to be losing more than just fat otherwise it would be all disproportionate lol. I've just had a low key worry that I might be losing more muscle than I thought, but the trend above seems to be OK, if it can be relied upon at all.