The results are in! Today, I got a hydrostatic body fat test to find out just how effective my low-carb lifestyle is. But before the big before and after photo reveal- here’s a little about how the test works.
A hydrostatic test is just a dunk test – you submerge your body in water after expelling all air from your lungs and measure what you weigh. From this (plus a series of additional calculations) you can figure out your body fat percentage. The method is accurate within 1% (making it the most accurate besides an autopsy, but that’s not exactly an option). Other methods of testing have the potential to be wildly inaccurate; it isn’t uncommon for caliper testing to be off by +/- 5-6%, even when done by a professional. That’s an error of about 9 lbs of body fat on a 160 lb person. For this reason, hydrostatic weighing is the “gold standard” for body composition testing.
Alright, enough explanation- The results! Since February 18th and today (104 days), I’ve lost 11.6 lbs of pure fat. I went from 28.4 lbs of body fat to 16.7 lbs. My body fat % (relative to total weight) went from 18.7% to 12.2%! Quite the improvement, I’d say! Keep in mind that I started strictly applying the Asian-without-rice lifestyle on January 1st, a while before my first hydrostatic test. So, I actually lost a lot for than 11.6 lbs fat!
Between Jan. 1st and Feb. 18th (my first hydrostatic test) I had already lost 14 pounds. So you might ask, what were my starting fat % and weight numbers?. Since I only had data from daily weighing with a bioimpedance scale (which can be fairly innaccurate, but gives a useful trendline), I used this plus some extrapolation from my hydrostatic tests to approximate some starting numbers.
So here’s what my 5 month progress looks like:
|Body Fat %||Body Fat Weight||Total Weight|
|January 1||22.5% (est.)||37.35 lbs (est.)||166 lbs|
|February 18||18.66%||28.36 lbs||152 lbs|
|June 1||12.22%||16.62 lbs||137 lbs|
If I can say so myself, not bad eh?
What I Did
Well first of all, I purposefully refrained from exercise. No cardio, no weight training. I wanted to prove a point. You can lose weight (and more importantly, fat) by just eating the right diet! (If you want to know the details of what that diet consists of, read about what exactly it is in my ketogenic primer).
Studies even show that people on diets whose compositions are lower in carbohydrates retain more lean body mass! This particular review (and you can find all of the specific studies cited at the bottom) notes that in one particular study, people with lower carbohydrate intakes lost weight of which 95% was fat tissue. The people fed slightly higher carbohydrate amounts lost 75% body fat and 25% lean body mass. Get this- not only did the lower-carbers improve their fat-to-lean ratio, they actually lost more weight overall! Check out this excerpt:
“Young et al. compared three diets containing the same amounts of calories (1,800 kcal/day) and protein (115 g/day) but differing in carbohydrate content. After nine weeks on the 30-g, 60-g and 104-g carbohydrate diets, weight loss was 16.2, 12.8 and 11.9 kg and fat accounted for 95, 84, and 75% of the weight loss, respectively. Importantly, underwater weighing was used to determine body composition.”
Even the higher-carb group was still on a relatively low carb diet. For a frame of reference: Most Americans eat about 50% of their calories in the form of carbohydrates. In the previously mentioned study, that would be about 225 grams of carbohydrate a day. That’s almost half a pound of carbohydrates a day!
Now, how does that apply to my results? Well, even though I would fall into the lower low-carb group (the 30 gram group), according to my hydrostatic results, I lost about 3 pounds of lean body mass. That puts me at about 77.5% weight loss as fat – a bit more than I had hoped. But then again, it still makes sense.
Here are a few factors that might explain why my lean mass decreased more than anticipated:
Dropped calories too low. In conjunction with my hydrostatic body fat test, I got my RMR (resting metabolic rate, or calories burned while doing nothing) analyzed using an indirect calorimeter. Basically, I relaxed and breathed into a tube for 15 minutes. The machine measures how much oxygen I’m taking in, and how much CO2 comes out. It’s an accurate measure of my unique RMR. Based on that info, I know approximately how many calories I burn while at rest and can assume that I burn an additional 200-400 calories a day from normal activity (Like walking, doing the dishes, etc.)
Low carb diets are satiating because you are eating more protein and more fat and these macronutrients take longer to digest than carbs, plus you have access to a constant supply of energy (body fat and ketones). You get hungry less. Thats a given. So it was far too easy for me to drop my calories to a very low deficit. I’m talking a wide range anywhere from 1100-1800 hundred a day. Some days I even forgot to eat until right before bed. When you drop your calories that low, you risk losing some lean body mass if your activity level is too high. And some days, I was notably more active.
Rhiannon (my fiancee), on the other hand, didn’t reduce her calories as much as I did. She did however, restrict carbohydrates to under 30 grams a day. She lost 8 pounds of total weight. 7.5 pounds were fat. She only lost 0.5 lbs of lean body mass, which is consistent with the results of the aforementioned study.
Intermittent Fasting (IF). In the last few months, I’ve read a lot about IF boosting fat metabolism without much loss of lean mass. A fair amount of the evidence supporting IF wasn’t purely based on science, but was more anecdotal. I figured it sounded compelling enough. So I tried it out. A few times a week, I went anywhere from 18 to 26 hours without eating anything. The fact that I had body fat and ketones to keep me energized made it all too easy to do. Well, it didn’t seem to work as intended. If you look at the graphs again, the last month of progress wasn’t impressive. So, I’m going to bet this, coupled with very low calorie, meant that during the long fasts, gluconeogenesis ramped up quite a bit and since no dietary protein was coming in, I lost more lean mass. And since I wasn’t working out, the dietary protein I had when I finally ate didn’t go towards rebuilding my lost muscle.
Again, interesting to note that Rhiannon didn’t try any intermittent fasting and she lost less lean body mass.
Cheat days. Every 5-6 weeks, I allow myself a day off where I eat whatever I want. It puts me a step back, but 5-6 weeks of strict <25 grams of carbohydrates a day is enough to put me two steps ahead in the long run. Unfortunately, a day of carbohydrates takes me out of the keto-adapted state and my body relies on glucose again for 2-3 days. A consequence is that the muscle sparing effect of ketosis wears off. Combine that with fasting and low calorie… bad news bears for lean mass.
Things I would do differently in light of my mediocre lean body mass results:
Eat MORE calories. As we know, calories aren’t really the determining factor, but living in a world where everyone touts that “calories in vs calories out is all that matters” kind of makes it hard to abandon the theory. Plenty of studies have shown that body composition improves with consumption of the same amount or MORE of calories with better macronutrient ratios (Refer to “Calories Matter… Sort of” for more information on this).
This is the big one - No intermittent fasting. It didn’t seem to work. I didn’t feel hungry, or shaky, or show any signs of hypoglycemia, but I did feel like doing less. (Again, refer to “Calories Matter… Sort of” to read about NEAT). Just briefly, based on the concept of NEAT, if you eat less, activity needs to decrease as a self preservation mechanism. In my case, my NEAT decreased and I didn’t feel crappy, I just didn’t feel like I needed to go do something. I actually starting noticing that I kind of just felt lazier in general on days that I went 18-24 hours without eating. Not hungrier or weaker… Just lazier.
Move around intentionally. Sort of. I wanted to see how much lean body mass I would lose given my almost completely sedentary lifestyle while dieting right. Unfortunately, my experimentation with intermittent fasting didn’t help the point I was trying to prove as far as lean mass goes. But my activity levels were very low anyways. You see, I work from home. My commute is a few steps into my home office… or the couch… or sitting up in bed. My work involves typing and holding a phone. My life is definitely what you would call sedentary. “Move it or lose it!” Rhiannon on the other hand, works long days in a lab where she is constantly moving around and picking things up.
Get more sleep! I use a Zeo – a dorky headband you wear at night that tracks your brain waves. It sends the data to my iPhone later so I can review how much light, deep, and REM sleep I got throughout the night. A quick glance at my history shows that I’ve been getting an average of 5.5 hours of sleep a night (sometimes much less). Terrible! That is sure to increase cortisol and all these bad hormonal responses in my body. Stress isn’t a good thing for weight loss in general – let alone for building or retaining muscle mass.
I shouldn’t focus much on the lean mass. And in all honesty – I am not. I’m pretty pumped about my results today! But I felt it necessary to explain why I didn’t retain as much lean mass as the lowest carb subjects in the study above. I really didn’t lose that much lean mass. The hydrostatic technician was actually impressed with how little lean mass I lost. The real question is, how much muscle would I have lost if I did all of those things on a non muscle sparing diet, like a low fat/low calorie diet? We know that on a low carb diet your body has a lesser need for blood glucose and focuses more on oxidizing fat and metabolizing ketones. This spares muscle. So, my bouts of 24 hour fasting didn’t cause too much harm. Could you imagine if my body was still dependent on glucose instead of fat and ketones? It would break down my muscle so fast in order supply the much higher glucose demand. It is probable that more than half of my weight loss would have been lean body mass instead of fat!
Future Game Plan
To reiterate, I didn’t exercise on purpose. I wanted to see the effects of my dieting behavior alone, without the exercise variable. Now that those results are in, in the next month or so, I will be starting my strength training regimen and see if I can lose these last 5 pounds of fat, and slap on some lean muscle mass to put me in the 8-9% body fat range!
Before & After
Oh and of course, a progress report without a before and after wouldn’t be cool would it? So, as embarrassing as that “before” picture is – Here you go!
Although I’m a lower body fat %, I haven’t worked out in months, so a little bit of strength training can really improve my physique. As you can see in the after picture, my fat tends to gravitate towards my lower abs and lower back. That is the last to go!