{"id":388,"date":"2011-04-28T10:43:10","date_gmt":"2011-04-28T17:43:10","guid":{"rendered":"http:\/\/www.engrevo.com\/blog\/?p=388"},"modified":"2012-03-16T08:46:19","modified_gmt":"2012-03-16T15:46:19","slug":"do-calories-count-2","status":"publish","type":"post","link":"http:\/\/www.engrevo.com\/blog\/do-calories-count-2\/","title":{"rendered":"Do Calories Count? 1st Law of Thermo (Part 2)"},"content":{"rendered":"

Despite breaking this post up into two parts (part 1 here<\/a>), this one is still a little long. Push through to the end, and you won’t be disappointed.<\/em><\/p>\n

Last time<\/a> we talked about the issues involved with applying the First Law of Thermodynamics to the entire human body as a control volume. Go back and read that post, especially the \u00e2\u20ac\u0153Summing Up\u00e2\u20ac\u009d paragraph at the bottom.<\/p>\n

All caught up to speed? Good, let\u00e2\u20ac\u2122s get going.<\/em><\/p>\n

Let\u00e2\u20ac\u2122s frame this discussion by first presenting the two most common fitness goals: losing fat, and gaining muscle. Of course, the holy grail of diet and exercise is doing both at once, often thought to be impossible; we\u00e2\u20ac\u2122ll take a look at this as well.<\/p>\n

Losing Fat<\/strong><\/span><\/p>\n

It is commonly stated that to lose fat, one must reduce the amount of energy stored in the body, and that this requires a caloric deficit. While these statements are certainly common, they are also certainly false.<\/strong> This falsehood arises from the (unnecessary<\/em>) complicating of the problem that results from applying the first law to the entire body. In the case of fat storage regulation, we should instead be viewing the collection of the body\u00e2\u20ac\u2122s fat cells as the control volume<\/strong>:<\/p>\n

\"\"<\/a><\/p>\n

To lose fat, more energy must exit the fat cells than enters them<\/strong> (meaning that the integral of the dE\/dt term must be negative over a given time). Note that this requirement says nothing about how to achieve this or the whole-body energy flow requirement.<\/em> All that is required for fat loss is a \u00e2\u20ac\u0153negative energy balance\u00e2\u20ac\u009d in the fat cells as a whole.<\/p>\n

Gaining Muscle<\/strong><\/span><\/p>\n

It is almost universally preached that to gain muscle, you must have a positive energy balance at the whole-body level. Hard-gainers (those who find it hard to gain muscle) are told in bodybuilding forums across the interwebs that they simply need to eat more. While it is certainly true that eating too little can prevent muscle gain, it is false that a whole-body energy surplus is required for muscle building.<\/strong> Hopefully, you see where this is going \u00e2\u20ac\u201c a first law analysis of muscle cells:<\/p>\n

\"\"<\/a><\/p>\n

To gain muscle, more energy must enter the muscle cells than exits them<\/strong> (meaning that the integral of the dE\/dt term must be positive over a given time). Note that this requirement says nothing about how to achieve this or the whole-body energy flow requirement.<\/em> A requirement for muscle gain is a \u00e2\u20ac\u0153positive energy balance\u00e2\u20ac\u009d in the muscle cells as a whole. In the case of fat loss, a negative energy balance is the sole necessary condition; for muscle gain, a positive energy balance is only one of the requirements.<\/strong> This leads in to the hormonal discussion in the next section.<\/p>\n

***********************************************************<\/p>\n

Sidebar: The difference between energy rate balance and energy balance.<\/strong><\/span><\/p>\n

The first law equations as I have written them are \u00e2\u20ac\u0153energy rate balances,\u00e2\u20ac\u009d evaluating the rate of energy change of the control volume. In the case of fat loss, the dE\/dt term denotes the rate at which energy is entering or leaving the fat cells at a given time. Let\u00e2\u20ac\u2122s see what the energy rate balance may look like over a given day (click to enlarge<\/em>):<\/p>\n

\"\"<\/a><\/p>\n

On an energy rate balance plot, each point is the rate of fat gain (positive) or loss (negative) at any given time<\/strong> (at time zero, the dieter is losing fat, at 10am, the dieter is gaining fat<\/em>). The energy rate balance starts negative and decreases until breakfast, at which point it spikes. It then begins to dip again until a second meal. The negative values until breakfast indicate that this individual is losing fat until breakfast, and storing fat between breakfast and bed time. Most people are not interested in losing fat at a specific time, they are instead hoping to lose fat over a given time period.<\/strong> To determine whether this individual gained or lost fat on this day, we must integrate the data (click to enlarge<\/em>):<\/p>\n

\"\"<\/a><\/p>\n

On an Energy Balance plot, each value is the amount of fat gained (positive) or lost (negative) over the day up to that point in time<\/em><\/strong> (at time zero, the dieter has lost a small amount of fat, at 9am the dieter has lost a lot of fat<\/em>). We see that the dieter has lost a lot of fat before breakfast, and that while the day\u00e2\u20ac\u2122s meals reduce the fat lost, the net result (final value at the far right of the graph) is that fat was lost on this day<\/strong>.<\/p>\n

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The Holy Grail \u00e2\u20ac\u201c Simultaneous Muscle Gain and Fat Loss<\/strong><\/span><\/p>\n

We\u00e2\u20ac\u2122ve shown above that fat loss requires a negative energy balance and that muscle gain requires a positive energy balance<\/strong>. If you\u00e2\u20ac\u2122re stuck with the flawed first-law model using the entire body as a control volume, this seems impossible, because the whole-body energy balance cannot simultaneously be both positive and negative.<\/strong> Fortunately for dieters everywhere, the energy balances of the fat cells and muscle cells can be different \u00e2\u20ac\u201c these equations are linked by the whole-body energy balance, but their values are not dictated by it.<\/strong> In fact, fat loss actually aids muscle gain, and vice-versa.<\/p>\n

Let\u00e2\u20ac\u2122s assume that the human body is very simple (it\u00e2\u20ac\u2122s not<\/em>) and incoming energy is only used or stored in three places: fat, muscle, and option \u00e2\u20ac\u0153C\u00e2\u20ac\u009d (huge simplification, but it works for the purposes of this discussion<\/em>). Here\u00e2\u20ac\u2122s a constraint on the energy rate balances in the body:<\/p>\n

\"\"<\/a><\/p>\n

We can integrate the above to yield the corresponding energy balance constraint:<\/p>\n

\"\"<\/a><\/p>\n

Some of the more astute readers out there may be asking \u00e2\u20ac\u0153Aren\u00e2\u20ac\u2122t you just applying the first law to the whole body, a method you decried in your last post?<\/em>\u00e2\u20ac\u009d Good question! I am. I\u00e2\u20ac\u2122m applying the first law to each energy storage\/utilization entity within the body, then applying a constraint over the whole body reflecting the conservation of energy. Now that we\u00e2\u20ac\u2122re viewing the body as a collection of control volumes (instead of just one), we have the resolution necessary in our model for intelligent discussion.<\/strong><\/p>\n

This more detailed model allows for different energy balances in different subsystems of the body.<\/strong> Let\u00e2\u20ac\u2122s look at how the constraint governs muscle energy balance:<\/p>\n

\"\"<\/a><\/p>\n

As outlined above, if the goal is to build muscle, then EMuscle<\/sub> must be positive. We can see in the above model that this can be achieved in a number of ways. The classic \u00e2\u20ac\u0153bulk\u00e2\u20ac\u009d approach (eating more) simply increases EBody. <\/sub><\/strong>It is clear that this will increase EMuscle<\/sub> if EFATCELLS<\/sub> and EC<\/sub> remain constant. Of course, in the complicated system of the body, changing one thing will often change others<\/strong> (pharmacists call these \u00e2\u20ac\u0153side effects\u00e2\u20ac\u009d), and we know that most people eating more to gain muscle will also gain fat. This is a huge bummer \u00e2\u20ac\u201c you\u00e2\u20ac\u2122re spending more money and time eating, and the food isn\u00e2\u20ac\u2122t all going where you want it to.<\/strong><\/p>\n

Hopefully, this model has made clear that there is a better option. If the dieter holds EBody<\/sub> and EC<\/sub> constant, but decreases EFATCELLS<\/sub> (making it more negative by using stored fat for energy), EMuscle<\/sub> will increase.<\/strong> This is how losing fat helps build muscle.<\/p>\n

Real-World Applications<\/strong><\/span><\/p>\n

This may seem like a lot of math and hand-waving (it is<\/em>), but it has value. I\u00e2\u20ac\u2122ve shown that concurrent fat loss and muscle gain is possible, but I haven\u00e2\u20ac\u2122t told you how to make it happen in your body. The key is, in a word, hormones.<\/strong><\/p>\n

To free up more incoming calories for muscle building without increasing your calorie intake, you have to burn more fat for energy than you did before.<\/strong> Let\u00e2\u20ac\u2122s talk about how to do that.<\/p>\n

Many people have trouble losing fat (largely due to poor diet) and as a result, we end up with explanations from doctors like \u00e2\u20ac\u0153your fat cells are a living organism; it is their mission to store fat and they don\u00e2\u20ac\u2122t want to let it go.<\/em>\u00e2\u20ac\u009d In people with a healthy flexible metabolism<\/a>, the collection of fat cells is more like a gas tank in a car, simply a reservoir of stored energy that can easily be filled or emptied on command.<\/strong><\/p>\n

Lower your carbohydrate intake, and your metabolism will become a lot better at burning fat for energy (beta-oxidation). Insulin does a good job of keeping fat in fat cells; the lower insulin levels generally seen on a low-carb diet will make your fat-cells act more like a gas tank and less like a jail cell.<\/strong><\/p>\n

Another option is to increase the proportion of EBody<\/sub> allocated to EMuscle<\/sub> by creating a hormonal environment that demands more energy for your muscles.<\/strong> You could achieve this with anabolic steroids, but I\u00e2\u20ac\u2122ve heard that will deflate your basketball<\/a> or something (more research needs to be conducted on the link between steroids and basketball air pressure<\/em>). A more natural way to get the job done is good, old-fashioned resistance exercise. Weight lifting will put your body in an anabolic state, funneling incoming energy to muscles for hours after your workout.<\/strong> It is worthwhile to note that while \u00e2\u20ac\u0153cardio\u00e2\u20ac\u009d also requests more calories at the muscles, it burns those calories for energy instead of using them to build muscle. Since you\u00e2\u20ac\u2122re burning more energy than you\u00e2\u20ac\u2122re storing (even muscle construction is a form of energy storage), you\u00e2\u20ac\u2122ll get hungry and eat more (now you\u00e2\u20ac\u2122re increasing EBody<\/sub> and not gaining any muscle, which seems silly<\/em>). Also, \u00e2\u20ac\u0153cardio\u00e2\u20ac\u009d, you know, kills you<\/a>.<\/p>\n

The Bottom Line<\/strong><\/span><\/p>\n

Applying the first law to the body as a whole is practically useless, until you break it up into smaller sub-system control volumes. \u00e2\u20ac\u0153Calories in, Calories out\u00e2\u20ac\u009d is still true, it\u00e2\u20ac\u2122s just stupid to say (especially over and over again<\/em>) because it doesn\u00e2\u20ac\u2122t offer any insight into how the body actually handles energy.<\/strong><\/p>\n

Success in achieving the typical fitness goals of losing fat and\/or burning muscle is dictated primarily by hormonal environment, but may be limited by whole-body energy balance. In other words, it\u00e2\u20ac\u2122s more important to have your hormones working for you than it is to worry about weighing and measuring food.<\/strong> A low-carb diet and resistance training are two powerful tools for creating a favorable hormonal environment.<\/p>\n

So drop the bread (and neurotic food relationship), lift a dumbbell, and provide this article to anyone who so much as whispers \u00e2\u20ac\u0153first law of thermodynamics.\u00e2\u20ac\u009d<\/strong><\/p>\n