Today there was a “dis­cus­sion” dur­ing lunch with cowork­ers that really frus­trated me because I was treated like my opin­ion and expe­ri­ences did not mat­ter, and was not allowed to even explain myself before being laughed at and shut­down. Not only was this com­pletely dis­re­spect­ful, it shuts down the abil­ity to have intel­li­gent dis­course on a sub­ject mat­ter, so to allow myself to move on past this, I decided to write my side of the discussion.

The topic in ques­tion was nutri­tion and how to lose weight. I’ve done a large amount of read­ing on this sub­ject mat­ter. As some­one who has strug­gled with his weight since he was a child, I’m finally at a point where I feel like I know what I need to do to accom­plish the things that I want to accom­plish and know enough about how the body func­tions to allow me to make those appro­pri­ate actions, even if I ignore them some­times. To that end, I’ve lost 40 pounds of fat about 5 years ago and have kept it off pretty well. My weight, itself, has fluc­tu­ated because I’ve gained mus­cle, got­ten stronger, and just gen­er­ally lead a health­ier life than I ever have in the past.

The topic in par­tic­u­lar was the the­ory that calorie-in/calorie-out (CICO) is the uni­ver­sal “law” that rules weight gain and weight loss, but this con­cept is a com­plete over­sim­pli­fi­ca­tion of a sci­en­tific law that is based on, The law of con­ser­va­tion of energy, or the first law of ther­mo­dy­nam­ics to be more specific.

Quot­ing Wikipedia (empha­sis mine):

The law of con­ser­va­tion of energy can be stated: The energy of an iso­lated sys­tem is constant.

I’m not say­ing that, ulti­mately, our bod­ies do not obey this law, they most cer­tainly do, but what I am say­ing is that the appli­ca­tion of it for weight con­trol is not appro­pri­ate and not very use­ful due to an over­sim­pli­fi­ca­tion of the law, and a lack of knowl­edge to be able to per­fectly bal­ance energy in vs. energy out.

The first over­sim­pli­fi­ca­tion is assum­ing that the human body is an iso­lated or closed sys­tem. While you can use this abstrac­tion to sim­plify ana­lyz­ing known sys­tems that are rel­a­tively iso­lated, the human body is too com­plex, too unknown to be able to really con­sider it an iso­lated sys­tem or do we have the abil­ity to iso­late it in a way that is significant.

The sec­ond over­sim­pli­fi­ca­tion that makes calories-in/calories-out a bad assump­tion when it comes to weight con­trol is that all of the calo­rie num­bers that you have access to are approx­i­ma­tions based on assump­tions that add a degree of error (both small and large). Let’s eval­u­ated a num­ber of these approx­i­ma­tions that would play into caloric bal­ance and how this, while not proof, makes the like­li­hood that caloric bal­ance is not the law of weight loss.

The first approx­i­ma­tion is basal meta­bolic rate. This is very dif­fi­cult to actu­ally cal­cu­late given how much we don’t know about energy expen­di­ture in the human body. Aver­age Body Tem­per­a­ture, Heart Rate, out­side tem­per­a­ture, how you are feel­ing, etc all play into how much energy your body spends just on gen­eral upkeep.

The sec­ond approx­i­ma­tion is the calo­rie count of food. This is based on a sam­ple size, and con­sis­tent recipe, com­po­si­tion, size, sourc­ing of prod­ucts, qual­ity of the food (in sea­son foods are more nutri­tion­ally dense and gen­er­ally have slightly higher calo­ries than out of sea­son foods), etc.

The third approx­i­ma­tion is the num­ber of calo­ries your body expends when you exer­cise. Each per­son is com­pletely dif­fer­ent, so your tread­mill telling you burned 300 calo­ries is a gross approx­i­ma­tion and I dare say a com­pletely use­less num­ber given the lack of infor­ma­tion that those devices have. Things like the body­bug are mod­er­ately more accu­rate because they take things like Gal­vanic Skin Response into account, but their cal­cu­la­tions are com­pletely hid­den and pro­pri­etary which makes them untrust­wor­thy with­out unbi­ased sci­en­tific review.

The fourth approx­i­ma­tion is the 3500 calo­ries in a pound of fat. If this is what you are bas­ing your weight loss on, you fail to take into account that you will not only be los­ing fat, but lean mass as well.

Gary Taubes, in Why We Get Fat? points out that, if CICO does rule our weight gain/loss, it would take only an aver­age of 20 calo­ries a day of caloric over-consumption to gain 50 pounds in 20 years. Given all of the approx­i­ma­tions above, CICO, to me, seems com­pletely an unlikely expla­na­tion of why we get fat.

It’s also well-known that insulin is the trig­ger of lipid syn­the­sis (mov­ing blood lipids into fat stores), so this seems a more rea­son­able expla­na­tion of the mech­a­nism of “why we get fat”. Unchecked insulin lev­els, as can be present in insulin-resistant indi­vid­u­als or diets com­posed pri­mar­ily of high-glycemic-load foods, one can rea­son, cause an increase in lipid syn­the­sis beyond the nor­mal range that the body needs to main­tain homosta­sis.

Keep in mind, also, that our fat stores are not sta­tic. Fat moves in and out of them con­stantly, so after we eat, we get a lit­tle fat­ter, and then as we need energy from that food, the fat is released back into our blood stream, so this fur­ther indicts insulin as the poten­tial cul­prit in weight gain. This video from the doc­u­men­tary Fat Head offers a pretty good expla­na­tion of how blood lipid and fat cells interact.