Energy Balance and Healthy Body Weight Presented by Adam
Dannehl, Brad Pohlmann, Tim von Behren
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The Problems of Too Little or Too Much Body Fat Obese
Overweight Underweight
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What Are the Risks from Underweight? Higher risk of death
during a famine Disadvantaged when sick Cancer death results from
starvation
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What Are the Risks from Overweight? Increased fat greatly
increases risk for many diseases 300,000 people die in USA each
year to obesity- related 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
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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 Menopause in women Smoking Alcohol intake Physical
activity
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How Fat Is Too Fat for Health Body Mass Index (BMI)
Calculation: weight/height 2 Waist circumference Reflects visceral
fatness in proportion to body fatness Disease risk profile
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The Bodys 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
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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
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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
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Body Weight versus Body Fatness BMI Limitations Athletes
(especially bodybuilders) Pregnant and lactating women Adults over
65
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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
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How Much Body Fat is Ideal? Societys approval Health Depends on
gender and age Men between 12% and 20% Women between 20% and 30%
Lifestyle makes a difference
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The Mystery of Obesity Metabolic factors Environmental factors
Eating behaviors
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Hunger Physiological influences Empty stomach Gastric
secretions Absence of nutrients in small intestine Digestive tract
hormones Endorphins
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Appetite Thought Sight Smell Sound Taste Note that obesity is
associated with decreased food sensitivity
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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
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Satiety Postabsorptive influences Nutrients in the blood signal
the brain about their availability, use, and storage As nutrients
dwindle, so does satiety Hunger develops
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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
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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
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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
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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
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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
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External Cues to Overeating Variety Generally leads to
overeating NOT the case for vegetables Human emotions Loneliness
Yearning Craving Addiction Compulsion Depression (sometimes)
Schedule Stress (comfort foods)
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Economic Factors Food pricing Availability Advertising and
hidden political agendas
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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? How the
Body Loses and Gains Weight
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The Bodys 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- (Smith et
al., 2007) 2-3 week adaptation period Generalized physical/mental
endurance as a function of time Glycogen depletion
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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?
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Claims Concerning a Low- Carbohydrate 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.
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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? Treatments? Why?
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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.
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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
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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
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Weight Cycling: A Poor Strategy for Weight Loss Body Weight
Variance Time Continuation results in more Death
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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
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The Gut is the Largest Endocrine Organ in the Body
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Gut Bacteria Control Gene Expression in Newborn Babies
Enterococcus faecalis including the genes coding for the PPARs! DNA
(Are et al., 2007) metabolites ( in PPAR- expression) BMR (Vael et
al., 2011)
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Bringing It Full Circle Basis for hypothesis: Decreased gut
microbial diversity and intestinal inflammation is associated with
adolescent obesity (Tilg & Kaser, 2011) Intestinal Bacteria Gut
Permeability Hormones Energy balance Hunger and Appetite The Food
You Eat Regulate inflammation if gut barrier dysfunctions
(especially fat and carbohydrate) so what CAN we do with this?
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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
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Moving to the Kitchen OR
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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?
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.
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Another Practical Application Peter Griffin is 42 years old,
510 tall (1.78 meters), and weighs 298 pounds (142 kilograms).
Calculate his estimated energy need (in Calories) per day to
maintain his current weight.
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Questions/Comments/Challenges? You are what your metabolism
does with what you eat. How will you program it?
