“Rev Up” Your
Metabolism
Presentation by:
Cindy Sass, RD,CDE
March 8, 2012
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Objectives
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Describe what metabolism is;
Discuss factors that influence metabolism;
Review common misconceptions about
boosting metabolism and
Provide evidence based recommendations
on how to “rev up” your metabolism.
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Metabolism.. What is it?
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Metabolism consists of the energy spent to
keep the heart beating, the lungs inhaling
and exhaling air, the cells conducting their
activities, the nerves generating the
streams of electrical impulses.
In short to keep all the processes going on
that support life.
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Metabolism.. What is it?
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The basal metabolic rate (BMR) is the rate
at which energy is spent for these activities.
BMR is usually expressed in kilocalories
per hour.
A kilocalorie (kcal) is the amount of energy
required to raise the temperature of 1 gram
of water, 1°C.
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Metabolism.. What is it?

The two major contributors to energy output
in humans are:
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Metabolic processes
Voluntary activities
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Metabolic contribution to energy expenditure
accounts for at least 2/3 of the energy spent in a
day.
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Determining Metabolism
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The metabolic rate is highest in the young
and decreases about 2% per decade after
growth has stopped.
It is higher in people with larger surface
areas.
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In two people who weigh the same, the taller,
thinner person will have a faster metabolic rate.
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Determining Metabolism
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Metabolic rate generally is lower in older
people and in females.
The key to the difference is in the amount
of lean body tissue or fat free mass.
Lean tissue is more active metabolically
than fat tissue even during rest.
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Determining Metabolism
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Fever increases the energy needs of cells,
raising the metabolic rate by 7% for each
degree Fahrenheit.
Fasting and constant malnutrition lower
metabolic output.
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Determining Metabolism
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Lean muscle mass
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Age
Gender – male or female
Height
Fever or stress
High thyroid gland activity
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Estimations of Energy Output
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Basal Metabolic Rate (BMR)
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1.0 kcal/kg/body weight/hour (Men)
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0.9 kcal/kg/body weight/hour (Women)
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Example:
Mark, 150 lbs
Change pounds to kilograms:
150 lb ÷ 2.2 lb/kg = 68 kg
Multiply weight in kilograms by the BMR factor:
68 x 1.0 kcal/kg/hr = 68 kcal/hr
Multiply the kcal used in one hour by the hours in a day:
68 kcal/hr x 24 hr/day = 1 632 kcal/day
Basal metabolic rate = 1 623 kcal per day
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Voluntary Muscular Activity
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The following are crude approximations
based on the amount of muscular work a
person typically does in a day.
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For sedentary activity add 40-50 % of the BMR.
For light activity (a teacher) add 55-65%.
For moderate activity ( a nurse) add 65-70%.
For heavy work (a roofer) add 75 -100%.
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Energy Spent on Various Activities
kcal/kg/hour (exclusive of BMR)
Sleeping
0
Washing dishes
1.2
Walking (3 mph)
2.3
Vacuuming floor
3.2
Typing rapidly
1.2
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Example:
Mark a Carleton U employee
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If Mark had a desk job, we could estimate
the energy he needs for physical activities
by multiplying his BMR kcal/day by 50%.
1,632 kcal/day x 50% = 816 kcal/day
Energy for activities equals 816 kcal/day
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Total for day 1 632 + 816 = 2 448 kcal/day
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Mental Activity
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Intense mental activity requires only slightly
more energy than resting.
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Question 1
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I have been a yo-yo dieter most of my life.
I have lost and regained the same 50 lbs a
few times now.
Have I messed up my metabolism?
Is there any hope for me?
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Answer
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Your metabolism is most likely slower
today:
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When people lose weight they not only lose fat,
they lose lean body tissue as well.
When people regain weight, usually they end up
with a larger body fat % and a lower lean body
mass %.
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Answer
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Rx:
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Add some strength training to your regime which
should also include a reduction in food calories
and some cardiovascular (voluntary muscular)
activity.
Building lean body mass will boost your
metabolism while at rest.
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Question 2
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I have heard that certain foods are fat
burning foods. Can these foods boost my
metabolism?
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Answer
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Don’t fall for fat burning foods.
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There are no studies that back these common
myths of foods like grapefruit and celery or being
fat burning foods.
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Drinking cold water will not significantly boost
your metabolism.
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Question 3
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I have a friend who is taking a supplement
with green tea which claims to boost
metabolism, is this true?
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Answer
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There are many metabolism boosting
supplements on the market today.
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Bottom line – don’t waste your money!
Some popular supplements that claim to boost
metabolism;
 Green Tea Extract
 Peppers, ginger
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Supplements
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There is limited evidence that any
supplement will boost metabolism.
Green Tea extract can cause bloating,
vomiting and indigestion and may contain
large amounts of caffeine.
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Question 4
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I saw a magazine ad that promotes
cleansing your body of impurities by fasting
a drinking a liver tonic. One of the benefits
of this process was to increase metabolism.
Can this help?
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Answer
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The idea that fasting or skipping meals is a
great way to cleanse the system of
impurities, speed metabolism and
encourage weight loss is just another myth.
Denying the body of food calories can slow
metabolism and encourage the storage of
energy in the form of fat.
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Question 5
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Does spicy food increase metabolism?
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Answer
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Spicy food may increase the metabolic rate
slightly, but not enough to make much of a
difference.
The difference may be found in the
observation that people usually eat less
when eating spicy food rather than bland
food.
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Question 6
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Now that I am in my 40’s I find it much
harder to keep to a healthy weight. Is this
because my metabolism has slowed down?
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Answer
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It is true that your metabolism slows down
as you age. For every decade after growth
stops your metabolism will slow down by
2%. This relates to a 4-5 % decline in your
metabolism since the age of 20. This
translates to 70 kcal/day.
Metabolism slows as we lose lean muscle
mass.
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Answer
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It is estimated that there is a 3 % decrease
in voluntary activity per decade so the total
effect on your energy intake per day would
be approximately 140 kcal/day.
This would translate into an extra 30
minutes walk/day of voluntary activity or a
reduction in calories ( 1 bread, 2 small
cookies.)
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Question 7
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Does working out with weights really make
a difference on metabolism?
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Answer
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Lean muscle mass is more metabolically
active than fat mass. Muscle will burn
more calories at rest.
A young woman, older woman, and older
man can have as rapid a metabolism as a
young man if they have the same amount
of lean tissue.
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Answer
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To build lean muscle mass, aim for two
sessions of strength training a week.
Strength training can include using hand
weight to do bicep curls, using weight
machines at the gym, calisthenics like
push-ups and abdominal crunches, Pilates
and some forms of yoga.
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Strength Training
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A recent study confirmed that strength
training boosts metabolism and improves
body composition.
The study included a group of men and
women ages 61-77.
The group participated in a 3 days per
week strength training program for 6
months.
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Strength Training
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After 6 months the strength training group;
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Got much stronger
Lost 6 lbs of fat
Gained 4.5 pounds of lean tissue
Started participating in more leisure time
activities on a regular basis
Had a 12% increase in total energy expenditure
This boost in metabolism meant that they were
burning 230 kcal more per day.
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Question 8
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Should I focus only on strength training for
exercise?
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Answer
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The biggest burn of extra calories comes
from voluntary activities – the more you
move, the more you burn!
Running, hiking, walking, cycling, fitness
classes, dancing, using cardio machines at
a gym.
Ideally 4-5 times a week for 30-40 minutes
each time.
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Calories burned during exercise
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Bicycling, light effort
Golf carrying clubs
Tennis (doubles)
Walking dog
Swimming, treading water
Sailing
422 calories
387 calories
422 calories
246 calories
281 calories
211 calories
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Question 9
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Is there a way I can boost my metabolism
by making better food choices?
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Answer
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The type of starches you pick may increase
your metabolism.
In a study a group of dieters that were
given low glycemic index foods vs. high
glycemic index foods, had a small increase
in their metabolism.
Low GI foods include oatmeal, legumes, all
bran, stoneground bread, apples.
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Answer
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The body burns many more calories digesting
protein. Protein may require almost 25% more
energy to digest compared to fat.
Replacing some carbs with lean, protein-rich
foods can jump-start the metabolism at
mealtime.
Healthy sources of protein include lean beef,
turkey, fish, white meat chicken, tofu, nuts,
beans, eggs, and low-fat dairy products.
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Question 10
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If I eat regular meals will it boost my
metabolism?
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Answer
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When you eat large meals with many hours in
between, you train your metabolism to slow
down.
Having a small meal or snack every 3 to 4 hours
keeps your metabolism cranking, so you burn
more calories over the course of a day.
Several studies have also shown that people
who snack regularly eat less at meal time.
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Summary
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To Rev up your metabolism:
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Build lean body tissue – engage in strength
training at least 2 times a week.
Move your body – voluntary activity burn lots of
calories.
Choose lean protein and low GI foods.
Eat regular meals and snacks – eat smaller
meals more often.
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Thank You!
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