I checked my body fat % with one of those handheld checkers today and used its results to calculate my lean muscle mass. I did this in May/June at around 290lbs and had a lean muscle mass of around 193. I am 268lbs right now and, according to today, have around 183 lbs lean muscle mass. I don't like the thought of losing muscle, but should I be concerned?
Diet: 90+% paleo (primal variant, includes some dairy--mostly cheese, and Lindt 90% chocolate 2x/week or so)... probably much higher than 90% in actuality, but food is conventional, not grassfed/organic/pastured, etc which knocks it down a bit and I like cheese
Exercise: Predominately walking, maybe 7-8 miles/week at a slow pace. Occasional jog/walk intervals, very occasional sprints, wrestling on the floor with the kids every other day or so. Did the insanity fit test this morning; that about killed me.
Proportionally, I am still much higher muscle:weight ratio than I have been in a long time, but I don't want to get down to 215lb only to have another 30lbs+ of fat still to lose.
I am no expert on this. But the information I have and my experiece is, is that the hand held devices are very unreliable. Where I work out there is one and when I do weight and meaurements every 3-4 months, they always do it. I have a higher quality scale (moderately expensive - not cheap!) at home that I trust much more and there is a significant diference in the readings between the scale measurements of fat% and muscle% and what the hand held gizmo reads.
It sounds like you are having good loss and doing all the right stuff. For where you are now our exercise regime looks good to me. Walking is great stuff. Yo could try picking up the pace a bit there, sometimes, as well as adding some mileage incrementally.
Bottom line: I wouldn't trust the hand held measurment device at all!
Truly, the handheld fat-measurement devices are not reliable. They're close to a joke; no offense. The gold standard of body fat measurement remains hydrostatic body fat testing. You submerge in a pool of water, blow out all the air from your lungs, and get a very precise reading. Of course, at this point you have no baseline measure for comparison purposes. So find a hydrostatic testing situation, get a session, and let that be your baseline for future body fat changes.
If you're serious about not losing muscle, consider adding some. Even a light routine of strength training helps in that respect.
Above all, keep wrestling with those kids. No one ever turned 70 and said, "If only I had spent LESS time with my kids when they were young..."
I think as you get lighter, your body requires less muscle than before to perform routine activities. Resistance exercise a couple of times a week will help retain what you have, but you still might lose some, especially if you lose a lot of weight and no longer have to move around 90 extra pounds every day.
1) Electrical impedance measurements of bodyfat are highly influenced by how hydrated you are.
2) If you wish to lose fat and muscle, diet and do not strength train. If you wish to lose fat and gain muscle, diet and strength train properly.
Is 215 pounds and reasonable body fat levels appropriate for your height? What's your goal body fat composition? If I were to wager a guess, you probably should go much lower body weight (180-190), don't know how tall you are though.