Six days ago I set off on a journey towards getting in the best shape of my life by running a series of short 5-day experiments. The idea is that each experiment that produces a favorable change in my body fat percentage and/or muscle mass will serve as a control for the next experiment, and the next experiment that produces favorable results will serve as a control for subsequent experiments, and so on and so forth … until rippling 6-pack abs make an appearance 😉 The key is that only a single variable will change from one experiment to the next, be it total caloric intake, the quantity and type of supplements, the distribution of daily nutrients, etc. to keep things as controlled and as “scientific” as possible.

Today, the results for the first experiment are in. But before we get to them, let’s see what the final body measurements look like.

Body Measurements
Body Weight 187.6 lbs
Body Fat (Impedance Scale) 14.6%
Body Fat (Skinfold Calipers) 11.57%
Body Fat (Average) 13.09%
Lean Body Mass (From Average Body Fat %) 163.05 lbs
Fat Mass (From Average Body Fat %) 24.55 lbs

Now the results. Here is a summary of important measurements throughout this experiment.

Day Body Weight Body Fat Lean Body Mass Fat Mass Deficit(-) / Excess(+)
1 189.0 lbs 13.35% 163.77 lbs 25.23 lbs 299 Cal
2 190.6 lbs 12.13% 167.48 lbs 23.12 lbs 211 Cal
3 189.8 lbs 13.84% 163.54 lbs 26.26 lbs 305 Cal
4 189.8 lbs 13.03% 165.07 lbs 24.73 lbs 356 Cal
5 187.6 lbs 13.13% 162.97 lbs 24.63 lbs 258 Cal
6 187.6 lbs 13.09% 163.05 lbs 24.55 lbs N/A

And here are totals and averages for all calorie logs this week.

Calorie Log Totals
Calories Eaten 12,663
Calories Spent 11,235
   Exercise 1,670
   Basal Metabolic Rate 9,565
Caloric Deficit(-) / Excess(+) 1,428
Calorie Log Averages
Nutrient Breakdown (Fat/Carbs/Protein) 21%/42%/37%
Grams of Fat 62.1
   Saturated 18.8
Grams of Carbs 276.6
   Fiber 45.5
   Sugar 36.4
Grams of Protein 250
Calories Eaten 2,533
Calories Spent 2,247
   Exercise 334
   Basal Metabolic Rate 1,913
Caloric Deficit(-) / Excess(+) 286

So, what do we have here? Well, throughout this experiment I ate a total excess of 1428 calories above my energy expendeture. Technically speaking, this should have resulted in a gain of 185 grams of body fat (there are about 7.7 calories in one gram of body fat), which is about 0.41 pounds.

What do we have instead?  A fat loss of 0.68 pounds! That’s right, by eating on average 286 calories more than I spent for 5 days, I lost 1.4 pounds of total body weight and my body fat % went down 0.26% (0.68 lbs) from 13.35% to 13.09%. Did I just invent a miracle diet and exercise regiment? Maybe… but most probably not.

Even though I lost 0.68 pounds of body fat which resulted in total lean muscle mass % increase of 0.26%, I have actually lost 0.72 pounds of total muscle mass in the process. Basically, by getting leaner I have also gotten weaker. Was this expected? Definitely not. I thought that by eating an extra 200-400 calories every day, at least 40% of which is from protein, I would not only preserve my muscle mass but also gain some.

So what do these strange results mean? The most likely explanation is that my body was still trying to reach an equilibrium given the new caloric intake – even though I ate more every day than I spent, I probably ate less extra calories than I did in the weeks/months prior to this experiment.

The body composition is very slow to respond to changes in diet, but it does respond over time. So if I was eating, say, 500 to 1000 calories extra for the past few months (I never really tracked it) and then all of a sudden I started eating 200 to 400 extra calories, the body will try to reach a new equilibrium composition at this new caloric intake, which will involve dropping weight, including muscle and fat.

Another possible explanation is that my basal metabolic rate was (and maybe is?) actually much higher than the 1913 calories per day that I estimated, so I actually ended up eating less than I spent. This might also be explained by the fact that I might have been eating more extra calories before the experiment – human metabolism actually adjusts to caloric intake, so if I was eating a lot more before the experiment, then my metabolism (both resting and thermic, which is basically body heat) would have been a lot higher than when I started eating less. Metabolism also adjusts to dietary changes and lags behind, but not nearly as much as body composition. So when I switched from eating more extra calories to eating less extra calories my metabolism might have been higher than predicted for the first few days. This could have resulted in greater total energy expended than consumed and, therefore, weight loss.

So, does this experiment confirm or reject the hypothesis I asked during experiment design?

Eating more calories than I expend every day will not result in body fat gain.

Although the results from this experiment actually do look like they support this hypothesis, there turned out to be a strange and unexpected weight loss coming from both body fat and lean body mass. This probably means that the experiment was poorly designed and needs to be improved. Even though I actually experienced fat weight loss at the end of this experiment while eating more calories than I expended, the percentage error in measurements for energy expended (exercise + metabolism) and consumed (food) is just too big when compared to the small amount of extra calories I aimed to consume (200 – 400 calories / day).

In order to be able to confirm/reject this hypothesis (and with it the “calories in = calories out” law) with more confidence, a new experiment will have to be performed where I eat at least 50% more calories than I spend daily. So, if on a given day I end up spending 1913 calories through BMR and 300 calories through exercise for a total of 2213 calories, I will aim to eat 1107 extra calories that day for a total of 3320. Eating such an large amount of extra energy will overshadow any errors in BMR, food energy and exercise energy that I record. Until then, no solid conclusions can be made.