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This is a complicated area of study and I’m going to summarize the facts
as best I can without turning this into a massive text book. I just finished reading all 400 pages of Physical Activity
and Obesity, which was edited by the (repeatedly) aforementioned Dr. Claude Bouchard and includes 19 chapters written
by 35 contributors with impressive academic credentials. There is a bunch of stuff about respiratory quotient, sympathetic
nervous system activity, free fatty acid concentrations, lipolytic response, lipoprotein lipase activity; the list goes on.
It
is all interesting and important information… for scientists, but I just don’t think you need to know all that
because the end result boils down to the same basic solution for getting in shape: - Eat
a healthy, Calorie-reduced diet that is low in bad fats, low in processed foods, and high in whole grains, fruits and vegetables,
low-fat dairy, and contains moderate amounts of lean meats
- Exercise frequently and at high intensities
That’s it. That’s what you need to do. There is a crapload of science behind all of
it, but the solution to the problem doesn’t change. Nevertheless, there is stuff that is valuable for the non-scientist to know. Therefore, I’ve
picked and chosen basic aspects of energy metabolism to relay here that I think will give you a solid understand of how things
work to assist you in your weight loss and muscle building goals, as well as armor you against dieting and fitness scams.
What is Metabolism?
According
to www.medterms.com, metabolism is “The
whole range of biochemical processes that occur within us (or any living organism). Metabolism consists both of anabolism
and catabolism (the buildup and breakdown of substances, respectively). The term is commonly used to refer specifically to
the breakdown of food and its transformation into energy.” In relation to fat loss, you are
mostly concerned with that last sentence and the rate at which it takes place.
The First Law
of Thermodynamics
This is the one that states:
“Energy can neither be created nor destroyed.”1 Energy can, however, change forms. Food contains energy
and this energy is measured in the form of a kilocalorie. A kilocalorie equals a thousand calories (lower case “c”)
and it can also be represented as a Calorie (upper case “C”).2 Whenever someone talks about “calories”
they are actually talking about “Calories.” Get it? To elaborate, the typical bottle of beer contains:
- 150 Calories
- 150,000 calories
- 150 kilocalories
Now you understand why, being the anal SOB that I am, I write Calories with a capital “C.” Back on track; food does more than taste
good and provide us with an excuse to invite hot chicks for a night out, it is a vital source of energy for our bodies, and
our bodies are constantly burning this energy or utilizing it in other ways. Portions of energy from protein can be synthesized
into muscle tissue, and carbohydrates and fat can be utilized as mechanical and heat energy. What it boils down to, quite
simply, is that because of the First Law of Thermodynamics, weight loss is a simple mathematical equation of Calories in vs.
Calories out. The energy you take in can’t be destroyed, only converted. When you take in more Calories than you burn
you create an energy surplus and this surplus gets stored as fat (a form of energy) or can also be converted to muscle if
you are weight training. Conversely, when you take in fewer Calories than you burn you are creating an energy deficit, and
your body is then going to burn off fat stores to compensate for the energy deficit. If you’re doing it wrong, you’ll
also lose muscle.
The vast majority of the scientific health community knows and accepts this. The First Law is the most secure
of all basic laws of science. Any “diet guru” who says that weight loss is something other than Calories in vs.
Calories out is contradicting hundreds of years of accepted science. In other words, these diet gurus are just plain fucking
wrong. I’m not a guru; I want to educate. What’s the difference? In my opinion an educator is someone
who diligently pores over relevant research to present an opinion that is as accurate a representation of the facts as possible.
Gurus just make shit up.
These diet and fitness gurus
call themselves “controversial,” like being a controversial is a good thing. They try to convince you that there
is some vast conspiracy that they don’t want you to know about and that they have the real secret
to weight loss.
What a bunch of assholes.
Let me ask you one question: The next time you get on an airplane, would you rather it was designed,
built and tested in a “controversial” manner, or in a scientifically proven and accepted one?
I thought so.
Counting Calories that go in is easy, it’s the Calories out part that gets really complicated,
and this is where metabolism (and genetics) comes in.
Important Caloric Measurements
Below is a list of accepted approximations:
Calories In - One
gram of protein contains 4 Calories
- One gram of carbohydrate contains 4 Calories
- One gram of
fat contains 9 Calories – this is one of the main reasons why eating too much fat makes you fat. It has a significantly
higher caloric density and it does a poor job of satisfying hunger
Calories Out - One
pound of stored body fat contains 3,500 Calories
- One pound of body muscle contains 2,500 Calories
In order to burn off one pound of fat, you need to consume about 3,500 fewer Calories than you
burn. This is called creating a caloric deficit. Unlike government budgets, in the case of weight
loss a deficit is a good thing. If you were to spread this out over the course of a week, it equals a daily deficit of 500
Calories to burn a pound of fat.
When done correctly, it is easy to ensure that (over time) all of the weight you lose comes from
fat stores and none from muscle. It is perfectly reasonable to expect that you can build muscle at the same time you burn
fat; this book contains the plan to do just that. Building muscle and burning fat are two different metabolic processes, and
the people who focus on muscle-building phases and fat burning phases are part of the bodybuilding crowd, which I believe
represents an unhealthy extreme. I encourage you to focus on building muscle and losing fat at the same time. Some good news is that weight training causes
a portion of your caloric intake to turn into muscle, which you want because it helps in creating an overall negative energy
balance (a caloric deficit). Although as I already pointed out the amount of energy in muscle is only 2,500 Calories, so the
effect is less. The lower amount of Calories required to build muscle is also why you don’t ever need to buy
so-called weight gainer powders.
Total Daily Energy Expenditure (TDEE)
When it comes to burning Calories, this is the overall number that you need to focus on; it is a function of
four different things: - Resting Metabolic Rate (RMR)
- Thermic Effect
of Food (TEF)
- Non-Exercise Activity Thermogenesis (NEAT)
- Voluntary Sport or Exercise (sorry, no acronym
for this one)
Resting Metabolic Rate (RMR)
RMR makes up the majority of most people’s daily caloric burn. It is the Calories you burn
doing nothing: just being alive. It maintains your body temperature, pumps blood, makes your brain and organs work etc. Every
time you engage in an activity you are burning Calories over and above RMR. In most sedentary adults, RMR accounts for 60-70%
of their daily caloric burn.3
Calculating your RMR (for men): (10 X weight in kilograms) + (6.25 X height in centimetres) – (5 X age) + 5 = RMR
Let’s do me. I weigh 79.5
kg (175 pounds), am 183 cm (6 feet even) and 40 years old. Therefore: 795 + 1143.75 – 200 + 5 = 1743.75 Calories per day burned via RMR. When it comes to figuring out the “Calories
out” portion of weight loss, you’ll find that there are a lot of approximations going on, so if you don’t
want to run through that calculation, then just take your weight in pounds and factor by ten and it will give you a good idea
of your RMR.
Thermic Effect of Food (TEF)
Good
news for a change, did you know that about 10% of the Calories you consume are freebies? This is because TEF burns Calories
in the act of processing them. However, not all Calories are created equal. The three different macronutrients (carbohydrates,
protein and fat) all have different TEF percentages: - TEF of protein is approximately
25% of its total Calories
- TEF of carbohydrates is approximately 10%
- TEF of fat is a subject for debate, but is likely
less than 5%4
Overall, about 10% of a typical
person’s daily energy expenditure will come from TEF.5 Also, before you decide to start a high-protein diet
because of its high TEF, make sure you read the next chapter on metabolic myth busting, because when you run the numbers it
doesn’t add up to bugger all.
Non-Exercise Activity Thermogenesis (NEAT)
Thermogenesis is a fancy word for the body creating heat, meaning that it is burning Calories. There are two
types of NEAT, voluntary and involuntary. Involuntary NEAT has a considerable genetic determinant because it comes from things
like fidgeting and toe-tapping. As I pointed out in the previous chapter on genetics, some people just can’t sit still
and this means they burn extra Calories throughout the day. Twitchy, annoying, lucky bastards.
Voluntary NEAT is every act
of movement you intentionally make throughout the day that does not qualify as sport or exercise. It is walking, cleaning,
job-related activity, yard work, taking out the garbage, and even sex (I assume that when you fornicate it is a voluntary
activity). The biggest variable for NEAT is often occupation. I sit on my ass all day staring at a computer, talking on the
phone, or in mindless meetings trying to make myself sound intelligent and look important; I don’t burn a lot of extra
Calories doing this. I do help around the house a fair bit though, so this adds to my total caloric burn above RMR.6
Exactly
how many Calories you burn in a day via NEAT is variable. The more time you spend on your ass, the lower the number. One of
the benefits of getting in good shape is that you will find you have higher energy levels and as a result your NEAT Calories
likely will increase as well because you will want to do more. Doing chores around and outside the house may not seem like
such a chore anymore because of your higher energy levels.
Calories Burned via Sport and/or Exercise
This is the one you have the most control over and from a fat loss perspective it is an important
tool in creating consistent caloric deficits. The calculation is simple: Intensity of Exercise X Duration of Exercise X Individual Physiology = Calories Burned Whenever you hear that [activity “x”]
burns such and such Calories per hour, they are leaving out the critical aspect of individual metabolic rate. Probably the
easiest way to get an approximation of how many Calories you burn from an activity is to factor
it by how much you weigh in kilograms as a percentage. To get your weight in kilos, divide your weight in pounds by 2.2. A
220 pound man weighs 100 kilos so his multiplier is 1, which is what most Calorie-burning charts are based on. I weigh 175
pounds which is pretty close to 80 kilos. Therefore, my multiplier is 0.8 for the following activities. If you weigh 105 kilos
(231 pounds) then your multiplier is 1.05. The figures below come from a variety of sources, and some are just plain best guesses on my part. | Activity | Calories Per Hour | My Kilo Multiplier | My Calories / Hour | | Basketball, moderate | 600 | 0.8 | 480 | | Basketball, intense | 1000 | 0.8 | 800 | | Cycling, moderate | 600 | 0.8 | 480 | | Cycling, intense | 900 | 0.8 | 720 | | Golf (walk and carry) | 400 | 0.8 | 320 | | Housework / Chores | 300 | 0.8 | 240 | | Running 5 miles/hr | 800 | 0.8 | 640 | | Running 6 miles/hr | 1020 | 0.8 | 816 | | Running 7 miles/hr | 1200 | 0.8 | 960 | | Skiing, downhill, moderate | 500 | 0.8 | 400 | | Skiing, downhill, intense | 700 | 0.8 | 560 | | Soccer, moderate | 700 | 0.8 | 560 | | Soccer, intense | 1100 | 0.8 | 880 | | Swimming, moderate | 500 | 0.8 | 400 | | Swimming, intense | 800 | 0.8 | 640 | | Walking, 3 miles/hr | 350 | 0.8 | 280 | | Weight training, moderate | 500 | 0.8 | 400 | | Weight training, intense | 700 | 0.8 | 560 |
As I already mentioned, there is a lot of guesswork when it comes to “Calories out.” Exactly
what your definition of “intensity” is plays a role, as well as other genetic and metabolic rate factors. The
above chart is just to give you a general idea of how many Calories you might burn in a given activity. Also, don’t forget when calculating
the above to subtract the number of Calories you would have burned had you not engaged in that activity. If you run
for an hour and burn a thousand Calories, you need to subtract the RMR Calories you would have burned had you just been lazing
on the couch during that hour (1/24 of your RMR) to get the total number of extra Calories this activity burned.
Here’s a picture to put TDEE into perspective:
Again, I’ll use me as a representation: - RMR
= 1,750 Calories per day (rounded) +
- TEF = Approximately 250 Calories per day (10% of daily caloric intake)
+
- NEAT = Approximately 400 Calories (if my wife doesn’t have a bunch of chores for me)
Subtotal TDEE = 2,400 Calories On my one day off a week from exercising (Sunday), that’s as high as my TDEE gets, but there
are three additional common exercise scenarios that I can add to this: - Weight training
only (Monday, Wednesday, Thursday): 400 extra Calories burned = TDEE of 2,800 Calories
- Running only (Friday, Saturday):
900 extra Calories burned = TDEE of 3,300 Calories
- Running and weight training (Tuesday): 1,300 extra Calories
burned = TDEE of 3,700 Calories
The above represents
about six hours of exercise a week. I do four weight workouts of 45 minutes each and three runs each lasting an hour. The
total amount of Calories burned through exercise each week totals about 1,600 from weight training and 2,700 from running,
for a grand total of 4,300 Calories. Again, these Caloric figures are all guesswork, but looking at my abs in the mirror tells me my
guessing ability is pretty good. Of course you aren’t going to jump into doing six hours of exercise each week, but it is
an eventual target that you may wish to have if you want to be in great shape and drop significant amounts of fat. At a minimum,
your eventual target should be three hours of intense exercise per week.
In Case You Hate Math
Here is a simple way to figure out a not bad approximation
of how many non-exercise Calories a day you burn. To quickly estimate RMR+TEF+NEAT: - If
you have a desk job and do very little activity during the day, take your weight in pounds and times by 13. This is me, although
I am closer to factoring by 14 because I do a fair bit of stuff around the house.
- If your job is more active and/or
you have to engage in some physical labor throughout the day then take your weight in pounds and factor by 15.
- If you are consistently
moving for much of the day, engaged in a lot of non-exercise physical activity, then I’m wondering why you’re
reading this book. Still if this is you, factor your weight in pounds by 1.7.
Close enough. Remember that these figures don’t include Calories burned via exercise, which you will be
engaging in soon.
Creating a Consistent Caloric
Deficit
It bears repeating that this is the critical
component of losing weight. In order to lose weight you must consistently burn more Calories than you take in. Measuring how
many Calories you take in is pretty simple, just read labels and/or use an online Calorie counter (Google it). As I’ve
already shown, measuring Calories out is more complex and subject to variance from person to person.
I’d like to point out
that counting Calories is not a critical factor for success. Many people lose significant amounts of weight through adding
lots of intense exercise, eating healthy and controlling their portions. They follow the rule of eating until they are “satisfied”
rather than “full.” You can try following the old
Chinese saying: “Eat until you are eight-tenths full.” This strategy works just fine, to a point. You can lose
most of the weight you want following this model. However, if your goal is to have visible abdominal definition then you are
probably going to want to start counting Calories at some point. I don’t keep a rigid written log of everything I eat
in a day, but I keep a pretty good track in my head that I figure is close enough.
Even if you don’t count them, it is
a good idea to have an understanding of Calories to increase the likelihood that you are creating a deficit week after week.
I prefer the method of establishing a weekly caloric deficit because you don’t want to have a significant deficit every
single day or there is the possibility that your metabolism will slow down in what is referred to as a “starvation response.”
It’s also no fun if you don’t get to take a day off once in a while.
What is Starvation Response and
How to Avoid It
I’m guessing that since you’re
a guy I won’t have a hard time convincing you that cutting your caloric intake in half for the next several months is
a bad idea. The hard part for you is going to be cutting Calories even a modest amount. Still, on the off chance you do decide
to go overboard on caloric restriction I am obligated to advise you not to do it.
Back in the 1940s when people were more tolerant
of being guinea pigs Ancel Keys conducted the Minnesota Starvation Study (actually, the participants were conscientious objectors
to WWII). Thirty-six men were subject to an extended period of 50% of their maintenance level caloric needs (the purpose was
to learn about how to medically deal with impending starvation as a result of the war – it wasn’t just a lark).
As a result of participation, the men’s metabolic rates dropped significantly partially due to loss of body mass, but
also due to an evolutionary advantage where the body uses fewer Calories during lean times.8
The starvation response
doesn’t sound like much of an advantage these days, but back when the hunt failed or there was a drought it sure came
in handy: it kept people alive. Another metabolic response programmed in by natural selection is “Poststarvation hyperphagia.”
I asked my wife (the doctor) what hyperphagia meant, and she replied with: “pigging out.” After a period of starvation
a hormonal response causes people to overeat way past what it takes to replace the lost weight, usually gaining more than
what they lost in the first place. In the bad old days, this extra fat protected them against the next time that food was
in short supply, but today it just causes yoyo dieting where the dieter ends up fatter than when they started.9
So how do you prevent the starvation
response? - Don’t cut Calories too drastically. An average-sized man should take
in minimum of 1,800 Calories per day. The minimum I take in on a daily basis is about 2,200, except for this one day after
a draft beer bender when I felt like, uh, never mind.
- Make your caloric deficits largely the result of activity.
As I mentioned, when focusing on dropping fat I take in at least 2,200 Calories a day, which is only 200 below my TDEE if
I don’t do any activity at all. Most of my big caloric deficits come from adding a bunch of exercise into the equation.
- Don’t
restrict Calories every single day. I’m guessing that when you start off that won’t be a problem, but when you
get serious about seeing those abs remember to take one day a week where at minimum you break even calorically. Better yet,
go a couple of hundred Calories over maintenance for the day. DO NOT use your “binge” day to go nuts. You can
wipe out three or four days of caloric deficits in one day of drunken gluttony. Not restricting Calories once a week also
has psychological benefits. I love Saturday because I run seven miles that day and therefore have a TDEE of about 3,400 Calories.
On that same day I take in about 3,600 or so Calories, 900 of which is from beer. If I didn’t get to do that once a
week I’d go batshit crazy.
Nutrient Partitioning
There isn’t a lot you can do about this, because
it is largely genetically determined. Dr. Claude Bouchard had this to say about nutrient partitioning: “…studies
indicate that insulin; steroid, thyroid and growth hormones; and various growth factors all influence the fate of ingested
energy… This line of research suggests that being a ‘fat storer’ as opposed to a ‘lean tissue storer’
is a risk factor for obesity.”10 Some people are destined to store fat and others build muscle. Like I wrote at the beginning of
the genetics chapter, whatever your genes are, you just have to suck it up because you’re stuck with them.
“My Friend Cut
Calories and He/She Didn’t Lose Weight. Why?”
If
you’ve ever listened to anyone talk about weight loss, you’ve probably heard someone say that “I only ate
1,200 hundred Calories of celery and tuna fish a day and I still didn’t lose weight. Oh, woe is me!”
How could this be?
Answer: they suck at math.
A number of studies have proven
two simple facts that explain this “phenomenon:” - Obese people drastically underreport
the number of Calories they take in. The more obese they are, the more they underestimate food consumption. They have a tendency
to “forget” about all the high sugar and high fat snacking they do during the day.
- Obese people
overestimate the amount of physical activity they engage in.11
When you underreport consumption by several hundred Calories and overestimate activity by several hundred Calories,
then your math is fucked and you stay fat. Solution: know that this can happen and make a commitment to be honest. If you
still aren’t losing weight, then get a Calorie journal and make the decision to write every little thing down. If you
choose to forget about a bunch of Calories then you’re only screwing yourself.
Conclusion
As I mentioned at the beginning, this chapter just covers the basics of metabolic rate and how
weight loss and gain works. The more exciting stuff is in the next chapter on metabolism myth busting.
Go to the Next Section
Previous Section
Notes - Hilary McGlynn (Ed.), Scientific American
Science Desk Reference, (New York: John Wiley & Sons, Inc., 1999), p. 135.
- Ibid., p.
11.
- Arline Salbe and Eric Ravussin, “The Determinants of Obesity,” Physical Activity
and Obesity, Claude Bouchard (Ed.), (Champaign, IL:
Human Kinetics, 2000), p. 70.
- Ibid., p 76.; Thomas Halton and Frank Hu, “The
Effects of High-Protein Diets on Thermogenesis, Satiety and Weight Loss: A Critical Review,” Journal of the American
College of Nutrition, 23 (5), 2004, p. 374.
- Salbe and Ravussin,
“The Determinants of Obesity,” p. 74.
- James Levine, “Non-Exercise Activity Thermogenesis,”
Nutrition Reviews, 62 (7), July, 2004, p. S82.
- Peter Kokkinos et al., “Exercise Capacity and
Mortality in Black and White Men,” Circulation: Journal of the American Heart Association, 117 (5), February
5, 2008, pp. 615.
- Abdul Dulloo and Jean Jacquet, “Adaptive
reduction in basal metabolic rate in response to food deprivation in humans: a role for feedback signals from fat stores,”
American Journal of Clinical Nutrition, 68, 1998, p. 601.
- Abdul Dulloo et al., “Poststarvation
hyperphagia and body fat overshooting in humans: a role for feedback signals from lean and fat tissues,” American
Journal of Clinical Nutrition, 65, 1997, p. 717.
- Claude Bouchard (Ed.), Physical
Activity and Obesity, (Champaign, IL: Human Kinetics,
2000), p. 8.
- Steven Heymsfield et al., “The Calorie: Myth, Measurement and Reality,” American Journal
of Clinical Nutrition, 62 (suppl.), 1995, pp. 1035S-1038S; Klaas Westerterp, “The Assessment of Energy and Nutrient
Intake in Humans,” Physical Activity and Obesity, p. 145.
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