Losing weight or losing LBM?

marissafit06

My goal with losing weigh is to reduce the total amount of fat on my body. However, I'm wondering how I know if the losses that I am observing are primarily body fat or are a mix of muscle and fat? I'd prefer to conserve LBM and am willing to adjust the rate of weight loss to conserve muscle. I'm okay with losing 10 more pounds and then focusing on body recomposition.

If it matters, SW 168.8, CW 155.5 GW originally 135, thinking of adjusting to 145. I do have a basis for my goal weights that are grounded in reality and have a small frame.

ETA: my diary is closed, but I eat 1700-2100 calories a day. I work out 6 days a week, 4 days of weights 2 days cardio, and get at least 12K steps each day.

TimothyFish

Anytime you lose weight, you lose lean body mass. To reduce or reverse that loss requires exercise.

marissafit06

yes I'm aware of that. I meant losing fat or lbm. As I stated, I'm wondering if there is a way to determine if the majority of weight being lost is fat loss or muscle loss.

marissafit06

Any other thoughts?

Cortelli

IMHO, there are three important factors to reduce the loss of muscle / LBM (note LBM includes anything non-fat, including organ tissue, tendons, bone, cartilage, etc.).

1. Protein. Especially when in a deficit, consuming adequate protein helps preserve lean mass. There is no "this is the absolute truth" protein amount, but if you're taking in approximately 1 gram per pound of LBM while in a reasonable deficit, you're probably doing about what you can do to reduce lean mass loss. A recent look at adequate protein intake in resistance-trained, lean individuals found that 1.1g - 1.4g per lb of LBM was more effective in retaining LBM during a deficit; others are comfortable with slightly lower amounts. Those individuals with a significant calorie deficit or already very lean should probably err on the high side.

2. Resistance training. Often lifting weights, but can be bodyweight training, etc. The key is to work your muscles with some effort, pushing towards failure. Think of it as a signal to your body along the lines of: "I know you need to convert mass to generate the energy needed (given my calorie deficit), but see, I really need these muscles - just look at the stress I am putting on them! - so please look elsewhere for stored energy. Hey, why don't you work some of that energy that is in the form of stored fat, instead. Lord knows it's available."

3. Reasonable calorie deficit. If you have a lot of fat to lose, perhaps this is less important. But as you get leaner, your body simply doesn't have the fat stores (or can't utilize the stores quickly enough given the deficit and activity) to rely on fat alone. When relatively lean, reducing the calorie deficit appears to aid in sparing lean mass. Put more simply, if you're close to goal / relatively lean, trying to lose 1.5 lbs a week or in some cases even 1 lb per week may necessitate utilizing lean mass for energy.

Cortelli

marissafit06 wrote: »

yes I'm aware of that. I meant losing fat or lbm. As I stated, I'm wondering if there is a way to determine if the majority of weight being lost is fat loss or muscle loss.

There's no sure-fire way. I've had the good fortune of being able to get a cheap hydrostatic weighing done every 3 months or so (but missed the last one) and done a DEXA scan as well. Both are attempts to determine how much of your bodyweight is fat versus lean mass (and other uses - DEXA common for bone density). If you google hydro weighing or DEXA or BodPod in your area, you may find a provider who can run a test for you at a manageable cost (I pay $30 for a hydro, and paid approx $100 for a DEXA, IIRC, but I've seen costs both higher and lower). I'm led to believe that often research universities might have a cheap option for you as part of their athletics program / education program in physiology, etc. - though in my case I found Stanford U to be more expensive than commercial providers in my area.

Even these tests are an estimate, but are generally reasonably accurate if performed correctly (+/- somewhere around 3%). In any event, they're both much better than any electrical impedance scale or device. Another alternative is a BF test using calipers, but your results may vary considerably depending on the skill and experience of the person administering the test / exam.

If not truly fascinated byt the whole process and data, then getting adequate protein, doing regular resistance training, and maintaining a moderate calorie deficit should considerably reduce any LBM loss while you're losing weight.