Is it normal to lose so much muscle?

[blackberry]

Hi,

I have an Omron scale that measures weight and body fat % using the electrical impedance method (scan is from the base of the scale, going through the feet; it is not a full-body scan).

I have been using it for a few months to monitor the progress of my diet. I am on a strict MWL diet with 30 minutes or more of stationary biking 5 days a week at about 60 - 70 % of my maximum heart rate.

What I have found is that I am fairly consistently losing about 65% of my weight from fat, and the rest - 35% - from everything else (muscle and bone). This is basically true over any multi-day, week, or multi-week period, give or take 5%. I realize the absolute body fat % given can be off significantly, but what I am interested in is the relative change. The scale has been very consistent.

In Dr. McDougall's MWL book, he talks about diet and exercise and its impact on muscle loss, saying that moderate exercise increases fat loss and reduces muscle loss. Unfortunately, I did not see any numbers for an idea of what I should expect. Is 1/3rd weight loss from muscle (and maybe bone?) a good amount? Or is that really high and I should be concerned? What can I do to increase the ratio of fat to muscle loss - losing more fat and less muscle?

Details:

Diet: One large Russet potato with onion and ketchup for breakfast and lunch. Optionally up to one pound of raw carrots as a snack. For dinner, either broccoli and potato soup in water, or a large spinach salad with a little bit of corn, peas, beans, and a legal dressing. Optionally one Russet potato after exercise, prepared the same (recent addition). One to three pieces of fruit (usually bananas) throughout the day.

I don't go hungry. I could eat a little less, actually.

I like to estimate everything: the potatoes average 250 - 300 calories each. All told, I am probably getting anywhere from 1000 to 1600 calories daily, varying on the size of the individual components (I don't measure everything, just like to have an idea on averages). I wonder if I should eat more calories?

Exercise:

Started at 30 minutes on the bike, generally biking at about 60% - 70% of my maximum heart rate, as defined in the MWL book. Many times I would get that up to 80% or so, but did not notice any appreciable difference in the percentages over the next few days.

As an experiment, two days ago, I upped this to 40 minutes (> 300 calories), at a consistent 60-70% max heart rate, and had salad an hour or so before the exercise, and a potato afterwards (the added potato). My hypothesis is that biking longer will burn a higher ratio of fat and less carbohydrate; when done, I will re-add the carbohydrate that was burned by eating the potato so that my muscles are not consumed for energy (if my carbohydrate reserve is depleted, the next thing to burn is muscle, then, after many hours, fat - by that time you are fasting or starving). It is too soon to notice any change with this experiment.


Let me know your thoughts! Thanks to all.

[hope101]

Hi, blackberry. A few ideas, but others will chime in. A potato approximately 3 1/2 inches x 4 inches is 275 calories. An average potato is closer to 150 calories. Without knowing how tall you are, your sex, and your age, I suspect you are undereating. 1000 calories is definitely too little, no matter what your age, activity and sex. I would also suggest you try to get in a good variety of fruits and veggies, particularly if you are sticking to one starch.

Without knowing the actual numbers, you need to be aware that the scales that rely on electrical impedence are not particularly reliable. If you are more hydrated on this diet, for instance, you will consistently get a different body fat percentage than if you are dehydrated. If you truly think you are losing muscle bulk, you might want to consider visiting a gym and getting some of the more sophisticated measurements for feedback. At minimum, measurement with fat calipers with the same measurer at intervals will probably provide you with a more accurate estimation of muscle mass than your scale.

Lastly, the best way to preserve and (even better), gain muscle is to do resistance training as well as your biking. It will help keep your metabolism revved, change your body shape in a pleasing way, build bone, enhance endurance and strength, and boost esteem faster than aerobic exercise alone. If you are new to resistance training, consider going to a gym and getting a personal program set up. Either something you can do at home using your own body weight and some tubes or free weights, or machines. Then you are doing the right thing and you can ignore your scale.

BTW, welcome to the board. Great to have you here.

[blackberry]

Hi hope!

One thing I forgot to mention is that, crazy thing, I am actually getting stronger - at least on the bike (have not compared upper body strength yet). I started at a difficulty level of 10 (out of 20) for 30 minutes, and quickly got exhausted when going higher. Recently, I was to the point where I would start at 10, and increase by 1 every five minutes, ending (before cool down) at 15 for the last 5 minutes. Now I am on 11 for 40 minutes, and could easily go higher.

Yes, I have been planning on adding strength training to my schedule to see if that would make a significant difference.

I was wondering about the electrical impedance method as well. It is the only thing that doesn't seem to fit, given that I appear to be getting stronger. The thing is, it has been incredibly consistent every day for months, and across multiple variations of a vegan diet and usually near-zero exercise (exercise is a recent addition). All of the diet variations were low in calories. I calculate the day-to-day delta in fat and muscle/bone, and also calculate it in different intervals spanning multiple days, weeks, or months. I don't think my math is wrong, but if you are curious:

weight * fat% = fat_weight
weight - previous_weight = weight_delta
fat_weight - previous_fat_weight = fat_weight_delta
weight_delta - fat_weight_delta = muscle_bone_delta

Anyway, I am not particularly worried about it; if it continues as it has, I figure that I will "look thin" when I am near the bottom of my "ideal weight range" (from the common chart). It is just that it doesn't seem right that my weight loss would be 2:1 fat:muscle by weight.

So, I have a follow up question. if increasing the ratio of fat:muscle weight loss involves eating more calories (assuming that is the case), how exactly does that work, metabolically speaking? I am just curious that if my muscles can burn fat for fuel, and they are chronically short of carbohydrate due to the diet, why wouldn't they burn the fat? Why isn't it always 100% fat loss when you are on a diet, and applying enough stress to your muscles to keep them at their same level?

Thanks for the help!

[Burgess]

In the situation described, and based on what little I know as a layman, I would have these concerns:
- Are you getting enough calories (e.g., 2000/day for an adult male of average height)?
- Are you getting enough variety of proteins?

Dr. McDougall discusses proteins here: http://www.drmcdougall.com/misc/2007nl/apr/dairy.htm

My conclusion from various pieces I have read here is that eating a low protein diet (as little as 35 grams/day) is very healthy, but only if:
- Enough calories are consumed to prevent the body from breaking down muscle to provide missing calories.
- The full range of amino acids (proteins) is being consumed so that none are missing.

A wide variety and sufficient quantity of fruits (of many different colors), vegetables, and starches (roots, gourds, and small quantities of nuts, legumes, and grains) will solve both problems.

I am six feet tall. I have followed the McDougall Program consistently for three years. I am at my lowest weight ever -- 135 pounds. I am very active, often walking two hours a day, climbing stairs, and doing light weight lifting. (I have no car.) My muscles are very lean, not bulging, but at age 63, I can out-lift most of my age mates (who can barely lift themselves off their couches).

Summary: Make sure you are getting enough calories and enough protein (both in quantity and in variety).

[DianeR]

I'm a believer in doing weight-bearing, resistance exercises in addition to aerobic work. If you are concerned about losing muscle mass, this seems to be the simple solution. It will also be good for your bones.

[hope101]

Blackberry, that's a great sign that you are getting stronger. You are on the right track wrt aerobic fitness for sure. And no doubt you are building some leg muscle as well.

What I was trying to say about your type of scale is that I doubt very much it is reliable about even the type of tissue you are losing. If you didn't have that body fat percentage, would you be concerned? If the answer is no, then I would ignore it. I think your instincts are right that this is a red herring.

Wrt percentage of calories taken from carbs vs fat vs protein, your body will preferentially burn them in that order. My understanding is, however, that your body can only access so much fat at one time, and if you are in enough negative caloric balance it doesn't get picky and starts to mobilize energy from any source it can get. Especially if you aren't telling your body you need your muscular stores by using them for strength, not just endurance.

If you don't mind me asking, are you losing weight really rapidly? Don't feel you have to answer, but I think we could help better if we knew how tall you were, your sex, and your weight and rate of weight loss. (I have a sense you are feeling a lot of pressure to lose quickly and might be undermining your long term health by pressing for an artificial goal.)

[blackberry]

Thanks for all the responses, everyone!

I don't want to answer too many of the personal questions because this is a public post, and I am a private person. But, for some of them: I am not under any pressure to lose weight, am a male, and losing about 3 lbs a week, which is about normal for me. I was not really concerned about the muscle loss, just confused.

In any case, thanks to everyone for the feedback; I have several possible explanations (not enough calories?, scale doesn't really work?, and this is normal - improve the ratio with strength training).

[hope101]

Oh, good. I got the sense you might be losing horrendous amounts of weight per week. Take care.

[serenity]

What I have found is that I am fairly consistently losing about 65% of my weight from fat, and the rest - 35% - from everything else (muscle and bone).

Wouldn't the 35 % non-fat loss also contain water? Surely you are not losing a pound of muscle a week especially since you are feeling strong. But I bet you would be losing water. I think it is part of the cell metabolism as fat and sugar are burned, CO2 and H2O are the final product. Many or most of us experience increased urination during periods of fat loss.

[DavidMR]

I'm a believer in doing weight-bearing, resistance exercises in addition to aerobic work. If you are concerned about losing muscle mass, this seems to be the simple solution. It will also be good for your bones.

I agree with DianeR 100%. It is very important to do weight-resistance exercise, in order to avoid losing muscle along with fat. I make it the dominant component of my workouts.

[rchess]

Another good reason to do weight training as you get order is that it builds bone density and strengthens joints.

Best Wishes

[susie]

Most likely you are losing fat from within your muscles. have you noticed when looking at a big steak how much fat is within the meat.The butcher calls this marbelling. Now meat is in fact muscle and our muscles also get some marbelling too. So if your muscles appear to be getting smaller, then it is my bet that the difference is fat.

SQ

[blackberry]

Yeah, that is an excellent point. It would explain why the scale is consistently wrong, or so I think, and why I am not getting weaker. I have been doing light strength training for about a week now, and have not noticed any decrease in strength. It is too early to notice an increase, though.

I also asked Dr. McDougall for his opinion, and he doesn't think I should lose muscle either (caveat being that I am doing it right, which I think I am).