Energy Balance and Healthy Body
Weight
Presented by Adam Dannehl, Brad Pohlmann, Tim von Behren
The Problems of Too Little or Too
Much Body Fat
• Obese
• Overweight
• Underweight
What Are the Risks from Underweight?
• Higher risk of death during a famine
• Disadvantaged when sick
• Cancer death results from starvation
What Are the Risks from Overweight?
• Increased fat greatly increases risk for many
diseases
– 300,000 people die in USA each year to obesityrelated diseases
– Hypertension
– Cardiovascular Disease
– Diabetes
– Abdominal hernias, arthritis, complications in
pregnancy and surgery, flat feet, gallbladder, gout,
high flood lipids, kidney stones, liver malfunction,
respiratory problems, sleep apnea, some cancers, and
varicose veins
Central Obesity
• Visceral fat
– Diabetes, stroke, hypertension, and coronary heart disease
– Faster lipid release rate
• Subcutaneous fat
– Slower lipid release rate
• Apples versus Pears
• Influencing factors
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Menopause in women
Smoking
Alcohol intake
Physical activity
How Fat Is Too Fat for Health
• Body Mass Index (BMI)
– Calculation: weight/height2
• Waist circumference
– Reflects visceral fatness in proportion to body
fatness
• Disease risk profile
The Body’s Energy Balance
• Change in energy stores = energy in – energy
out
• Because body fat is so calorically dense (3500
Calories per pound), changes in daily energy
intake/expenditure only cause body fat to vary
over time
How Many Calories Do I Need Each
Day?
• Daily caloric intake depends on:
– Basal metabolism
– Voluntary activities
– Thermic effect of food
• Basal metabolic rate (BMR)
– Factors:
• Age, height, growth, body composition, fever, stress,
environmental temperature, fasting/starvation,
malnutrition, and thyroxine
Estimated Energy Requirements (EER)
• Quick estimation:
– Men: kg body weight x 24 = cal/day
– Women: kg body weight x 22= cal/day
• Precise calculation takes into account:
– Gender
– Age (valid only for people 19 and older)
– Physical activity
– Body size and weight
Body Weight versus Body Fatness
• BMI
– Limitations
• Athletes (especially bodybuilders)
• Pregnant and lactating women
• Adults over 65
Measures of Body Composition and
Fat Distribution
• Anthropometry
– Fatfold test and waist circumference
• Density
– Underwater weighing or displacement
• Conductivity
– Bioelectrical impedance
• Radiographic
– Dual energy X-ray absorptiometry
How Much Body Fat is Ideal?
• Society’s approval
• Health
– Depends on gender and age
– Men between 12% and 20%
– Women between 20% and 30%
• Lifestyle makes a difference
The Mystery of Obesity
• Metabolic factors
• Environmental factors
• Eating behaviors
Hunger
• Physiological influences
– Empty stomach
– Gastric secretions
– Absence of nutrients in small intestine
– Digestive tract hormones
– Endorphins
Appetite
•
•
•
•
•
Thought
Sight
Smell
Sound
Taste
– Note that obesity is associated with decreased
food sensitivity
Satiation
• Cognitive factors
– Presence of others, social stimulation
– Perception of hunger, awareness of fullness
– Favorite foods, foods with special meanings
– Time of day
– Abundance of available food
Satiety
• Postabsorptive influences
– Nutrients in the blood signal the brain about their
availability, use, and storage
– As nutrients dwindle, so does satiety
– Hunger develops
Leptin: Master Regulator
• Produced in adipose tissue
• Suppresses appetite (not hunger)
– Negative feedback mechanism
• Regulates:
– Female reproductive system (fat reserves)
– Capillary density
– Arterial constriction
– RBC formation
Energy Nutrients and Satiety
• Glycemic Index
– Relatively poor indicator of satiety in the context
of meals because macronutrient interactions are
not well studied
– Fructose/Glucose ratio is largely ignored
• Protein and fat confer high satiety due to slow
transit and metabolism
– Fiber has a similar effect
• Simple sugars stimulate satiety only briefly
Selected Metabolic Theories of
Obesity
• Enzyme theory
– Elevated lipoprotein lipase
• Increased triglyceride storage
• Fat cell number theory
– Fat cells increase in number and size during
childhood
– Fat cells only increase in size during adulthood
• Set-point theory (supported by previous
theories)
– Recently revised to the settling-point theory
Set-point Theory
• Thermogenesis
1. Brown adipose tissue
a. More metabolically active than white adipose tissue
b. Decreases with age
2. Body adjusts to environmental and behavioral
stimuli (i.e. temperature and food intake)
3. Diet-induced theory (as a function of body
weight)
1. Postprandial metabolism in lean/obese
2. Weight as a function of energy expenditure
Genetics and Obesity
• Identical vs. fraternal twins
– Identical twice as likely to weigh the same
• Genetic influences determines tendency for
obesity
• Lifestyle determines if this tendency is realized
External Cues to Overeating
• Variety
– Generally leads to overeating
– NOT the case for vegetables
• Human emotions
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Loneliness
Yearning
Craving
Addiction
Compulsion
Depression (sometimes)
• Schedule
• Stress (comfort foods)
Economic Factors
• Food pricing
• Availability
• Advertising
…and hidden political agendas
How the Body Loses and Gains Weight
• Daily weight fluctuations
• Nicotine suppresses hunger
• Moderate weight loss versus rapid weight loss
– Which one reflects changes in stored fat?
– Which one is associated with protein sparing?
The Body’s Response to Fasting
• Ketoacidosis
– What is it? Who is affected?
– What are ketone bodies?
– Is KETOACIDOSIS basically the same as KETOSIS?
• Ketosis (fasting)
– Initial Conditions:
• Nerves are incapable of metabolizing ketones
• Fat canNOT be converted to glucose
• Protein CAN be converted to glucose
– Final Conditions
• Nerves are capable of metabolizing ketones
•  mitochondria,  PPAR-δ (Smith et al., 2007)
Glycogen depletion
Two Paths to Ketosis
• 1) Fasting (caloric restriction)
• 2) Efficacy of Low-Carbohydrate diets
– Why are there mixed results? (Phinney, 2004)
• Keto-adaptation period
• Potassium loss (famous “Turkey Study”)
– Cooked meat, broth discarded
– Absence of fruits and vegetables
• Protein dose
– Too high?
– Too low?
Claims Concerning a LowCarbohydrate Diet
• Claim #1: “People who have a healthy body weight
consume between 45-65% of energy as carbohydrate.”
• Claim #2: “Ketosis is associated with muscle mass loss.”
• Claim #3: “Ketosis is a dangerous medical condition.”
• Claim #4: “Ketosis injures the intestinal lining.”
• Claim #5: “Observing the equation calories in equals
calories out is the best strategy for weight loss.”
Counting Calories to Lose Weight…
Fundamental flaws:
1. “A calorie is a calorie” violates the second law of
thermodynamics (Feinman and Fine, 2004)
 Macronutrient ratios ARE relevant
2. Because most energy is expended during rest and
not while exercising…
3. Cardio Purist Syndrome
Who is affected?
Why?
Treatments?
Weight Gain
• Excess amino acids?
– Nitrogen stripped
– Glucose/fat conversion
• Excess fatty acids?
– Glycerol-fatty acid separation
– Glycerol oxidation
• Excess carbohydrate?
– Glycogen conversion
– Burned or stored as fat
• Alcohol
– Burned or stored as fat
– Slows down fat catabolism
Note: This is why Atkins (high
protein) without exercise (muscles
require protein for repair) may
result in weight gain.
Achieving and Maintaining a Healthy
Body Weight
• The DRI and most health professionals
recommend:
45-65% Calories from carbohydrate
20-35% Calories from fat
10-35% Calories from protein
• The current scientific literature recommends:
0-5% Calories from carbohydrate
80-85% Calories from fat
15% Calories from protein
More Strategies for a Healthy Body
Weight
• Distinguishing energy density and nutrient density
• Eat breakfast
• Workout early in morning for weight loss
– Caffeine blocks pain receptors
–  basal metabolism…
• …during the hours following exercise
– 15 minutes of intense anaerobic work is effective (Body by Science)
• …as proportion of lean tissue increases
• Exercise when hungry
1. Suppresses hunger
2. Reduces stress
Body Weight Variance
Weight Cycling: A Poor Strategy for Weight Loss
Continuation results in…
more
Time
Death
Bariatric Surgery as a Last Resort?
• Pros:
1. Lowers the set-point for obese individuals (Farias et al., 2011)
2. Increases satiety
•
•
Ghrelin suppression (Roux et al., 2006)
Cons:
1. Psychosocial complications (Sarwer et al., 2005)
2. Copious sugar consumption curbs weight loss following the
procedure
Methods
The Gut is the Largest Endocrine Organ
in the Body…
Gut Bacteria Control Gene Expression
in Newborn Babies…
(Vael et al., 2011)
metabolites
DNA
Enterococcus faecalis
(Are et al., 2007)
…including the genes coding for the PPARs!
( in PPAR-γ expression)
Δ BMR
Bringing It Full Circle
• Basis for hypothesis: Decreased gut microbial
diversity and intestinal inflammation is associated
with adolescent obesity (Tilg & Kaser, 2011)
(especially fat and carbohydrate)
Intestinal
Bacteria
The Food You
Eat
Gut
Permeability
Hunger and
Appetite
Hormones
…so what CAN we do with this?
Energy
balance
Regulate inflammation if
gut barrier dysfunctions
A Critical Time for Mom and her
Microbiotta
1. Factors affecting maternal microbiotta quality
– Antibiotic usage
– Probiotic usage and avoiding sugar
2. Birth method (Goldani et al., 2011)
– Cesarean section
– Natural delivery
3. Breastfeeding (Woo et al., 2008)
– WHO and AAP recommendations
– Lactation rooms
Baby Set-Point
Programming
Moving to the Kitchen
OR
Considering Saturated Fat
We already know to avoid trans fats, but…
1. Are there really any studies showing that
saturated fat forms arthritic plaques?
2. Is there any conclusive evidence that
saturated fat consumption itself contributes
to obesity or metabolic syndrome?
• http://www.youtube.com/watch?v=v8WA5wc
aHp4
• http://www.youtube.com/watch?v=mNYlIcXy
nwE
A Practical Application
Eric Cartman is 3 feet 4 inches tall (1.0124 meters) and
weighs 90 pounds (41 kilograms). Calculate his BMI and
identify his weight class.
Real kewl guys.
Another Practical Application
Peter Griffin is 42 years old, 5’10” tall (1.78
meters), and weighs 298 pounds (142
kilograms). Calculate his estimated energy
need (in Calories) per day to maintain his
current weight.
Questions/Comments/Challenges?
You are what your metabolism does with
what you eat. How will you program it?