xpost: Hydrostatic testing: need help reading the tea leaves (long)

This is going to be long, and I'd love some perspective on this data! I posted this on the general forum, as well.

I had my hydrostatic test done today. I am still attempting to wrap my head around what it all means. Here is what it said:

Dry weight: 167.4
Wet weight: 2.86 (does that really mean I weigh almost 3 lbs under water? LOL!)
Body fat percentage: 24.5% (the handheld tagged me at 29% on Friday).
Weight of body fat: 41.1 lbs
Lean body mass percentage: 75.45%
Weight of lean body mass: 126.3 lbs
Resting metabolic rate: 1742 calories/day

This puts me just about at the 65th percentile for women my age (45), and places me at the top of the "Good" category.

A body fat percentage of 23.5% (losing about 2 lbs of fat) places me squarely at the 70th percentile and "optimum health" range. He did say that seeking a body fat percentage of anything lower than that becomes cosmetic.

So here is where things get interesting. The guy administering the test was really impressed that my surgeon got me SO CLOSE to optimum body fat percentage with my goal weight of 160. He asked me a lot of questions how doc arrived at my goal of 160. I explained that it had to do with my starting/presurgery weight of 258, and that he simply drove it off of BMI. The guy was still impressed.

Regarding goal weights - part of the report had this chart:

% fat - target wt - to lose
24 - 166.3 - 1.1
23 - 164.1 - 3.3
22 - 162 - 5.4
21 - 160 - 7.4
20 - 158 - 9.4
19 - 156 - 11.4
18 - 154.1 - 13.3
17 - 152.3 - 15.1
16 - 150.5 - 16.9

He flagged the 18 because that would put me at 154 pounds and in the 90th percentile, the same value as performance athletes - something to shoot for.
My doc's goal of 160 would put me at 21% body fat, landing between 80 and 85th percentile which is highly athletic.
My personal goal of 150 would put me at 16% body fat, landing at about 95th percentile, beyond performance athletes.

Based on the above, I am seriously rethinking my goals. Based on this, I am thinking that my target goal should be 155-160 instead of 150. I am apparently teeter tottering on the boundary between burning fat and burning muscle, particularly because my typical daily caloric intake of ~800 calories is so very far below my RMR of 1742 calories. According to materials they gave me, my lean mass weight of 126 lbs means I need between 85-90 grams of protein each day, which is where I have been. The guy administering the test indicated that I should remain on the high protein low carb approach that I am on, but consider increasing my carbs through low GI carbs. Here is where I am stumped. What happens if I get more protein than I need? Which is going to be better for me, adding low GI carbs or adding fat?

So, my decisions at this point:
1. Deciding whether to change my goal weight, and if so, what to
2. Deciding to modify my nutrition or not. I haven't been working with a NUT, but perhaps it is time. What do you think? Another option is to stay the course. It seems to me that this data will give me an opportunity to fine tune/customize a plan to my body's unique needs, but I'm not sure what that is.

Either way, I am THRILLED with these results and am extremely proud of the fact that this is undoubtedly the best shape I have ever been in.

Thanks for reading this far.

Laurie

Where does one have hydrostatic testing done?

I'm so proud of you!  It took a lot of hard work to get where you are - thanks for sharing the results!

Way to go, Laurie!   Really proud of all the hard work you've done and everything you've accomplished.  I'm going back in for my second hydrostatic weighing session later this month and doubt that I'll come close to your fabulous numbers :-)   

I think a goal weight of 155 seems pretty ideal, then you have 160 as your "red zone".  Either way you'll be at a healthier body fat percentage than most of the women in the US.  As for what to add, the lower GI carbs or fat, I'll let people a whole lot smarter than me about that stuff weigh in.  Since I've already hit maintenance I'm doing both.  

I've been tracking my BF% using an Fitbit Aria scale since day one and your numbers all make sense to me.  In fact, they mirror very closely what I've learned and/or observed except for adjustments needed to balance the male/female differences between us.

I'm currently 17.4% per the scale, and my shape matches the visuals for that range which you can find on a Google search.  So my first piece of advice is to do the online search for those pictures and compare what you see in the mirror with the pictures by BF%.  It will help you determine where you might set your target.  For example, on the male chart, at percentages below 10% you can clearly see the level of body building required to achieve those levels.  Since I am not headed in that direction, it made it real easy to rule out any percentages that low.

When I look at the charts for women, it seems to me that 15-25% are the optimal ranges, but let's face it, within that range it's really a matter of personal preference.  Also, just because you achieve a certain percentage doesn't mean the distribution will match the pictures you see.  You mostly have to figure out how to get your head happy with the results which ever way they go.

Before you get to wrapped up in the numbers, congrats on the 23.5%.  With that figure you have to assume you've essentially lost 100% of your excess weight.  With that in mind, relax a little on the weight aspect while continuing to focus on the body fat percentage.  Sure, you might drop a few pounds along the way, but train your mind to focus on BF%, and fitness goals, and let the scale do what it does.

You seem to be on the right track, and I'm not sure anyone can answer the questions for you at this point except yourself.  There are so many personalized variables like exercise type, and duration, along with diet.  However, I would suggest getting a scale that measures your body fat (if you don't already have one) simply so you can monitor your lean mass vs. fat % on a routine basis.

I've wondered myself about those high end percentage and percentiles. With the VSG, burning fat is relatively easy if you stay on the program, however, we aren't really reaching those "performance" levels like an athlete would. Let's face it, the VSG alone isn't going to put me on par with an olympic caliber swimmer.  For now I'm just assuming that if I continue to loose fat, without loosing lean mass, while increasing my level of fitness via exercise, then all is good.  But you're right that maintaining that balance is a fine line to walk.

BTW: I did something like what you did with your chart also.  Using the data from the scale I mapped out a grid cross referencing BF%, BMI and weight.  From that I'm aware of what my possible weight targets are but am unconcerned with the final number.  My focus has been on trying to decide just what level of BF% is achievable, and monitoring that along with maintaining my lean mass.

Stay in touch, it sounds like we're basically doing the same thing.

 

Laurie, wow, this is wonderful news! Congrats to you on getting into such great shape!

I don't know a whole lot about this stuff (hopefully Keith and Jubjub will chime in), so take my opinion with a huge grain of salt, but I would think answering your questions would depend on what your goals are. Aside from a weight number, how much of an athlete are you looking to become? If you are going to seriously train for something, you may have to modify your diet to accommodate that (though I wouldn't worry so much about the weight number at this point - the body composition is more important).

As for a nutritionist, I have never seen one. But it seems the quality of them varies a bit based upon what I have read here. Some are not familiar with bariatric diets, and I would think some are not familiar with diet needs for athletic people. But it's worth checking out.

Have you discussed any of this with your personal trainer? Some of them know a lot about diet.