Body Fat Measurement via BodPod

Well, I got the answer I was looking for. I went to the West Virginia University Human Performance Lab and had my body fat percentage measured with the BodPod.

My numbers came back as:

  • Body Fat: 25.3%
  • Current Weight: 193.3 lbs
  • Lean Body Mass: 144.4 lbs

So to get to my 15% Body fat number, I need to get to:

144 x 1.15 = 166 lbs

So I still need to lose 27 .25 lbs. I should be able to do this if I stick with the PSMF diet for the next few months.

Which Metric does it Correlate Best with?

The USN Calculator puts me at 25.0% Body fat. That’s very close to BodPod number and is much closer than both the caliper method (17%) and my body composition scale (30%).

What about Exercise Factor?

The whole idea about muscle vs fat is oversold. According to Lyle McDonald an untrained person can put on something like 2 lbs of muscle in a month. And that is for someone young, etc. But let’s assume that in 3 months I can actually put on 6 lbs of Lean Body Mass as muscle. That would put my LBM at:

144.4 + 6 = 150.6 lbs

At 15% Body Fat that would be

150.6 x 1.15 = 173.2 lbs

So there’s only a bit of leverage with the muscle. Instead of having to cut weight to 166 I could cut weight to 173.2 lbs. Either way, that’s still 20 lbs down from where I am now. And that’s the maximum amount possible.

Put another way, that 6 lbs of LBM gain results in 7.2 lbs less of fat loss needed. It does help somewhat with Base Metabolic Rate.

 

PSMF – A Day’s Food/Supplements/Exercise/Biometrics

I’ve completed a day of logging everything with CRON-o-meter. Here’s the data entry part:

Bio-metrics were Weight, Body Fat percentage (from the scale), Body Temperature (used to determine if metabolism has dropped) and Blood Glucose.

Exercise was logged (CrossFit with warm-up and the resistance training portions).

Finally, the food I ate was carefully and completely logged. So how did I do compared to my goals? For overall calories I overshot by 2%. That’s great since I should never go under with PSMF.

The overall breakdown was also pretty good. I went under on my fat and over on my protein which balanced each other out. I did not exceed the carbohydrate number (net grams less than 20). That put me at a net deficit of 1131 calories. That would be about 2 lbs per week of loss.

 

Logging your numbers

I’ve been using spreadsheets to log my food, weight and other numbers.

A co-worker introduced me to CRON-O-Meter which is a good website for doing this logging. They have a lot of tutorial videos.

The site has a lot of standard food nutritional values and allows macros to be easily tracked. You can also enter weight, body fat percentages and exercise.

Here’s a screenshot of the site.

Body Fat via Skin Fold Measurements

I borrowed a friend’s body fat calipers to measure my body fat. Measurements were:

14, 20, and 12 mm. Running the calculator gave me the following:

I am skeptical about the results. I think my numbers are higher in percent fat and fat mass (with lower lean mass) than that. My USN tape measurement number is around 25%. My scale has me at 30% body fat.

This matters because if my LBM is 161 lbs and my goal is 15% Body fat then my goal weight would be 185 lbs.

Methodology

Jackson, A., & Pollock, M. (1978). Generalized equations for predicting body density of menBritish Journal of Nutrition, 40(3), 497-504. doi:10.1079/BJN19780152 (Full Text).

  • Men
    BD = 1.10938 – 0.0008267(Y) + 0.0000016(Y^2) – 0.0002574(Age)
    where Y= sum of Chest, Abdominal and Thigh skinfolds in mm
  • Women
    BD=1.0994291 – 0.0009929(Z) + 0.0000023(Z^2) – 0.0001392(Age)
    where Z = sum of Triceps, Thigh and Suprailliac skinfolds in mm.

Once body density is determined, percent bodyfat (%BF) can be calculated using the Siri equation below : % Body Fat = (495 / Body Density) – 450.

 

Using a Body Composition Scale

To do the following you need a body composition scale and a calculator.

If your scale tells you your body weight (as all scales do) and also tells you your body composition percentages the math is pretty simple to get to the lbs of body fat, water weight, etc.

To get the lbs of body fat take your body weight and multiply it times the percentage then divide by 100. For example, if your scale says you weigh 200 lbs with 30% body fat that’s:

200 x 30 / 100 = 60 lbs of fat

Some scales break out the water weight on it’s own and some include it by itself. If your percentages work out to more than 100% total then the scale is measuring body water independently of the other numbers.

My scale breaks weight down into:

  • Body Fat %
  • Body Water %
  • Muscle Mass %

So as an example if my scale shows:

  • Weight: 200 lbs
  • Body Fat: 32%
  • Body Water 37%
  • Muscle Mass 28%

That corresponds to:

  • Body Fat: 200 x 32 / 100 = 64 lbs
  • Body Water 37% = 200 x 37 / 100 = 74 lbs
  • Muscle Mass 28% = 200 x 28 / 100 = 56 lbs

Tracking the percentage is only so useful. What you really should care about is:

  1. Losing lbs of Body Fat
  2. Maintaining or gaining muscle mass

Water weight will follow since it tends to stabilize and increase with fat loss.

Bottom Line

Ignore your scale weight ups and downs. Instead do the math and track your lbs of body fat as well as your muscle mass numbers. They don’t tend to fluctuate as much as body weight.

P.S. Some Notes on Scale Accuracy

No scale is 100% accurate or even anywhere near it. But they are fairly repeatable and as such can be used for tracking purposes. For some useful notes on scales, here’s one article of many.

 

One Year on the scale

I found my scale numbers from a year ago. This was about 10 weeks after I started Keto so it doesn’t show my full weight drop. But it does show some great trends.

Date Weight BMI Body Fat % Total Body Water % Muscle Mass % Body Fat lbs Body Water lbs Muscle Lbs
2016-10-11 248.2 34.0 40.3 28.0 21.1 100.0 69.5 52.4
2017-09-29 197.2 27.0 30.9 38.0 28.4 60.9 74.9 56.0
Difference -51.0 -7.0 -9.4 10.0 7.3 -39.1 5.4 3.6

Weight is down 51 lbs. That’s a lb a week. A decent number.

Body fat dropped by almost 40 lbs of the 51 lbs lost. That’s a great result.

Water lbs is up! That’s really good and signals a recomposition.

Equally important is that my muscle lbs has gone from 53 to 56 lbs. Not huge but definitely my muscle mass has not suffered from a year of keto and fasting.

 

Protein Sparing Modified Fast (PSMF) – Two Weeks In

I am two weeks into this Protein Sparing Modified Fast. How do the results stack up so far? My current Scale (vs Original scale) numbers are:

  • Weight: 198.6 (203.3) 4.7 lbs down, Predicted Weight: 197.5 lbs.
  • Body Fat: 31.2 (32)%. down 1.6% of body weight (-3.2 lbs), Predicted Body fat loss: -5.02 lbs.
  • Muscle:  28.2 (27.6)%, down -0.2 lbs.

That’s pretty good. 6.3% of loss was muscle loss, 93.7% of loss was fat loss. So this WOE is definitely protein sparing. Just not hitting the amount of body fat loss that the table predicts. Will need to scale the time to achieve my goals. Interestingly enough the protein loss was very similar to the number reported by Yang on a water-only fast. Still it’s hard to draw a definitive conclusion from a bathroom scale.

Water retention has been relatively good with my %H2O going up from 36.9% to 37.7% (which correlates to an actual weight drop of 0.26 lbs). This isn’t a diet which dumps a lot of water plus I had just been on a loss before starting this WOE. Also, I’ve been able to keep up with needed electrolytes. I may even be overdoing them. In PSMF it seems easier to take care of electrolytes than a water-only fast. The Whey Protein Powder has a lot of the electrolytes in them plus vitamins. Protein itself may help and the fiber in green vegetables probably contributes. I’ve been eating Chia Seeds to keep up the fiber as well.

Dietary compliance has been pretty good/easy. I have been consistently hitting or slightly exceeding my daily macros within a few percentage points. It’s a bit of a juggling act and some pain to do daily tracking of the macros, but my spreadsheet makes it easier.

Exercise (CrossFit) has been varied but well tolerated. I am mostly in the phase of neurological adaptations now and on occasion I do something right enough to not be told to change it. Not putting on muscle mass isn’t all that big of a deal in this phase of my adaptation. I don’t see myself becoming a body builder and I don’t want too much muscle mass anyway. But I can imagine that doing body weight things like chinups and pushups will be a heck of a lot easier with 28 less lbs of fat. Running is already getting easier.

Sticking with my initial goal of 15% body fat. Scale says 31.2% which is significantly different than the USN calculator value of 24.1%. This article suggests that bathroom scales include the water that is in fat cells in their water results. That may give a clue as to why the fat number and water numbers are not quite what is expected. Particularly if some fat is being replaced by water (See the Whooosh Effect).

Update (2017-09-28): Link to Lyle McDonald’s article on the whooosh.

Semi-random Thoughts

Working on a weird theory about stalls. Sorta relates to the whoosh effect theory.

But in reverse. In the beginning of keto we lose something like 60% of our weight loss from water. But eventually that water imbalance levels out. So it is possible that we are consolidating our losses of water from our initial loss. The scale shows a long stall but we are still losing fat mass.

One piece of evidence is when I got my new scale at the beginning of keto it showed my water weight at a very low percentage. Pretty much the bottom of the scale for water percentage. My number back then was 28% of weight from water.

My other thought is that I could care less about weight loss. I only care about fat loss. And that is the more profound of the two thoughts.

Protein Sparing Modified Fast Calculator

I put together the previous formulas into one single webpage, the Protein Sparing Modified Fast Calculator. I’ve put my own current numbers into the calculator. Just hit the “Calculate” button to see my numbers. Feel free to try it out with your own numbers and see if it helps you figure out any of this. I don’t see the numbers you enter nor are they stored in any database. All of the calculations are done on your phone web browser or Internet browser (Firefox and Chrome works but Internet Explorer doesn’t).

If you find any errors, please let me know. I tried it with my own numbers and they make sense but I didn’t have a woman’s secret numbers to check.

Here’s a decent introduction to the Protein Sparing Modified Fast (PSMF). I only take exception to one point which is the question of how long you can do a PSMF. They say you can’t do it for an extended period of time. If you continually re-calculate your numbers you should be able to fine tune for maintenance levels. This calculator makes that re-calculation relatively easy. Here’s the results I got for my numbers.

Your Scale and Metabolism Numbers

Current Weight: 199.8 lbs
Goal Weight: 171.3 lbs
Lbs from Goal Weight at start: 28.5 lbs
Body Fat at start: 25.4%, 50.8 lbs
Lean Body Mass (LBM): 149.0 lbs
Basal Metabolic Rate (BMR): 1818.0 cal/day
Initial Total Daily Energy Expenditure (TDEE): 2500 cal/day
Initial Maximum Fat Loss on Protein Sparing Modified Fast: 0.45 lbs of body fat per day

Notes

Protein Sparing Modified Fast (PSMF) Dietary Macros (per day)

It is very important on the PSMF that you eat at least the macros listed here. If you go below these numbers you risk lowering your metabolism and you actually can’t lose body fat any faster. Attempting to be just above the numbers is OK.

Protein: 119.2 g (476.8 cals)
Carbs: 20 g (80 cals)
Fat: 40.9 g (367.7 cals)
Your total Dietary Calories are 924.4 cals for maximum fat loss.

If you consume 216 g (1943 calories) of fat you will stay at your current weight.At your goal weight you will be able to consume 119.2 grams of Protein, 20 grams of Carbs, and 176.3 grams of Fat.

Notes

Can You Fast?

One important question to ask when considering extended fasting is whether or not you have sufficient body fat to fast.

You currently use 2500 cal/day. You have 1575 calories per day available from your body fat for maintenance. You have less calories available from body fat than your daily requirements and may not be able to fast. If you fast, your body may drop your base metabolism, energy expenditures or may consume protein stores. You will be -924 calories short per day

The thermic effect of food contributes somewhere from 5-20% of your current TDEE number so if you are fasting that can reduce your TDEE. Reducing your TDEE by 10% would result in you using 2250 calories per day. Calculating in a 10% Thermic Effect of food still leaves you in a caloric deficit during fasting. The Protein Sparing Modified fast solves this issue by providing the calories needed for the deficit.

How Much Muscle Can You Gain?

The Maximum Lean Body Mass that you can carry on your frame is 186.5 lbs at your goal of: 15.0% Body Fat. That would be a weight of 214.5 lbs.

Disclaimer

Use this information at your own risk and with the advice of your medical professional. We are not doctors nor do we pretend to be one on the Internet. We do not take responsibility for errors in these calculations. We do not guarantee that these numbers will work for people at the extremes of the ranges. If you discover an error in calculation, please let us know through email: keto at land-boards dot com.

Body Recomposition – Part 3

What Will I Track?

When I started keto I tracked everything. That lasted about a week and then I slipped into a pattern of eating.

Currently, I track nothing formally. I do keep carbs below 20 grams (by approximation). After years of having an Insulin pump I got pretty good at estimating my number of grams of carbs. I check myself periodically with new foods to see how close my guess was and I am usually right on.

But to do this experiment right I will track the following

  • All meals I eat
    • Grams of Carbs
    • Grams of Protein
    • Grams of Fat
    • Do the math for percentage of each over a day
    • Do the math for total calories per day
  • Scale numbers
    • Weight
    • BMI
    • Body Fat Percentage
    • Base Calories to maintain current weight
  • Workout times (assuming effort is to exhaustion due to CrossFit)