Losing More LBM/Muscle Than Fat?

alexreyn13

I know when you create a caloric deficit you will lose body fat along with muscle/lbm. The larger the deficit, the more muscle/lbm you potentially lose. But is it possible to lose more pounds of muscle & lbm than pounds of fat when losing each week? Or is your fat storage the body's primary source of backup energy?

StealthHealth

My understanding is:

Generally energy utilization is Carbohydrate (glycogen) > Fat > Muscle.

Glycogen tends to get used up pretty quickly with large deficits, whether that is through fasting, limited eating, exercise or a combination. Fat utilization is then the norm but in cases of high energy deficit fat utilization can be insufficient and you will use muscle.

Can you metabolize more muscle that fat? - Yes, but only in extreme circumstance where glycogen and fat is completely depleted. In other words when you are starving to death (note: Not "starvation mode" but actually starving.

In practical terms it is worth remembering that the body is complex and the processes dynamic. So, throughout a day you may utilizing any of the fuel types, depending on your energy requirements but also that when eating you are replenishing or rebuilding those fuels (again at varying rates).

StealthHealth

In practical terms:

• Sufficient dietary protein
• Avoiding rapid/aggressive weight loss regimes
• Strength type exercise

should help minimize muscle loss.

Mycophilia

You could hypothetically eat at maintenance calories, but keep protein intake really low and stay in bed 24/7 to really get muscle atrophy going. You wouldn't lose any fat, but lots of muscle.

Hypothetically.

mitch16

StealthHealth wrote: »

My understanding is:

Generally energy utilization is Carbohydrate (glycogen) > Fat > Muscle.

Glycogen tends to get used up pretty quickly with large deficits, whether that is through fasting, limited eating, exercise or a combination. Fat utilization is then the norm but in cases of high energy deficit fat utilization can be insufficient and you will use muscle.

Can you metabolize more muscle that fat? - Yes, but only in extreme circumstance where glycogen and fat is completely depleted. In other words when you are starving to death (note: Not "starvation mode" but actually starving.

In practical terms it is worth remembering that the body is complex and the processes dynamic. So, throughout a day you may utilizing any of the fuel types, depending on your energy requirements but also that when eating you are replenishing or rebuilding those fuels (again at varying rates).

Actually, your body may metabolize more muscle than fat even if your fat isn't completely depleted. Still in the "starving to death" mode, but your body has a primitive instinct to try to preserve some level of fat for survival.