Nutrition E3: Energy balance & Weight managment

Energy balance & Weight managment

Excess energy is stored as:

fat

fat is used as _____ between meals

energy

Energy Balance

energy in = energy out

Direct Calorimetry

• measures foods energy via bomb calorimeter

Indirect Calorimetry

measures foods via oxygen consumed

Determinants of food intake:

• Controlled by Hypothalamus: hunger center

• Hunger vs appetite

• Satiation:

• Satiety:

• Stress can override hunger & satiety

• Disordered eating

• cognitive influences

• Habit

Satiation

• lets brain know when full during meal(tells brain to stop eating)

• Protein & high fiber foods are most satiating (protein most)

• Low-energy density foods: low satiation and satiety

satiety

• lets brain know if you are still full or not, “don't start eating again”

• High-fat foods: strong satiety signals

• Low-energy density foods: low satiation and satiety

Energy out determinants

DMR, Physical activity, thermal effet of food, adaptive thermogenisis

Basam Metabolism (BMR)

1. what you burn at rest after a 12 hour fast, ⅔ of energy expended a day

Thermal effect of food

1. calories it takes to digest food, about 10% of the kcal you take a day

Adaptive Thermogenesis:

1. the bodies response to its normal kcal burned due to outside factors, i.e. dieting, change of temperature, etc.

esting metabolic rate (RMR)

BMR but with no fast, so what your body normally burns throughout the day while having ate

Physical Activity

• Biggest component of energy expenditure

• Higher muscle mass leads to higher BMR

• Frequency, intensity, & duration can affect BMR level

Define healthy Body weight:

• Not appearance based

• Subjective

• Little in common with health by itself

BMI

A relationship based on someone's height & weight

Underweight BMI

 below 18.5, affects <2% of US population, elderly/sick, eating disorders

Healthy weight BMI

18.5-24.9

Overweight BMI

above 25

obese BMI

30 or more

BMI equation

Weight(lbs)/ Height(in)/ height (in) x 703= BMI 

healthy weight benefits

Absence of risk factors associated with blood cholesterol, sugar, and pressure

fat in ____ is more dangerous than fat in hips

stomach

Body composition, Men(20-40 y/o) )should be:

18-20%

Body compostion: women should be:

23-26%

Central obesity(apple shape)

–Common in men and in women after menopause

–Increased risk of heart disease, stroke, diabetes, hypertension, cancer

Central obesity(apple shape) waist circumference men & women:

greater than 40” men

greater than 35” women

Lower body fat(pear shaped)

–Common in women

–Low risk of disease

Underweight risks

Fighting against wasting diseases

Menstrual irregularities/infertility

Osteoporosis and bone fractures

fat calories

Used more efficiently & more directly converted to BF

Takes 5% of energy to store fat

Obesity

300,000 lives a year lost due to obesity related diseases(CVD, diabetes, cancer), 2nd cause of premature death

Bmi greater than 35 doubles…

premature death

Overweight risks

CVD, type 2 DM, cancer, likely to become disabled, costs($), yo-yo dieting

Disordered eating types(3)

Anorexia, Bulimia, Binge-eating disorder

-Anorexia Nervosa

95% female, young, overachiever, distorted body image, refusal to maintain weight, fear of gaining weight

Anorexia Nervosa Consequences 

Leads to protein energy malnutrition similar to marasmus (Impacts brain function and judgment), Denial, weak heart, Impaired immune response, Anemia, Atrophy of digestive lining, Low blood protein, Low BP and temperature, Fertility problems

Anorexia Nervosa Treatments

Low risk- counseling, Intermediate risk- counseling, high protein, high calories snacks, High risk- hospitalization, possible feeding tube

Bulimia Nervosa

Normal weight, females, some males, white, educated, high achievers, binge purging cycles

Bulimia Nervosa Consequences

Compromised immune system, Fluid/electrolyte imbalances, UTI’s that lead to kidney failure, Irritation of upper GI tract, Rupture of the esophagus and stomach

Bulimia Nervosa Treatments:

Develop regular meal patterns and counseling

-Binge eating disorder

Less restrictive during “dieting “ phase, consume less during binge and rarely purge, Feel out of control, distressed

binge eating treatment

behavioral and drug therapies.

Food deprivation & dehydration of athletes leads to…

Impair physical performance: Reduce muscle strength, Decrease anaerobic power, Reduce endurance capacity

Tips for addressing eating disorders

Don’t restrict amounts to less than USDA food patterns, Eat frequently, reasonable goal, Support groups help

Fat first fills _______ tissue. Then begins to be deposited in organs including________

adipose(fat);  heart and liver

Fat Cell Development

1. During growth Fat Cells increase in numbers

2. Energy intake exceeds expenditure, fat cell size increases

3. Energy intake continues to exceed energy expenditure, fat cells increase in numbers again

4. With fat loss, size of cell decreases but not number of cells

Lipoprotein Lipase

Enzyme, promotes fat storage, located on fat cell membranes, Obese ppl have increased LPL activity, increases after wt loss, regulated by hormones

Dietary fat oxidation

correlates negatively with body fatness, obese people have decreased oxidation activity

Set point theory

Metabolism adjusts to restore original weight after loss or gain

Genetics Cause of obesity

Determine a person’s predisposition to obesity

Biological children with obese parents are more likely to be obese than adopted children

Epigenetics Cause of Obesity

influence of the environment such as diet and activity on gene expression

Obesity gene:

named= ob,Codes for the protein leptin (hormone in hypothalamus)

Leptin…

• Promotes negative energy balance

• Suppresses appetite

• Increases energy expenditure

rare cause of obesity

Rare genetic deficiency of leptin or receptor mutation

effect if leptin injections on body weight

reduce body weight in animals and humans

Ghrelin

protein, produced by stomach cells that enhance appetite and decreases energy expenditure, promotes weight gain/triggers desires to eat, promotes positive energy balance

lack of sleep

increases ghrelin and decreases leptin

Recommended physical activity:

60 min /day of intense physical activity

Obesity health risks:

Hypertension, fatty liver disease, abnormal blood lipids, diabetes or prediabetes, sleep apnea

Obesity psychological problems: 

Depression, shame, rejection, embarrassment

Alli/Orlistat/Xenicle (drug) Action:

blocks digestion & absorption of fat in GI tract

Alli/Orlistat/Xenicle (drug) side effects:

GI cramping, diarrhea, gas, frequent pooping, reduced absorption of fat soluble vitamins

dangerous weight interventions

• Diet books/weight loss programs, fad diets, weight loss products, herbal & dietary supplements(dont need FDA approval), gummies

Aggressive treatments for obesity

surgery, must have BMI > 40 or BMI > 35 w/ weight health problems, Clinaclly severe obesity, Reduces food capacity of stomach, reduces ghrelin

Weight loss surgery: Gastric bypass (Bypasses stomach)

Surgeon constructs small stomach pouch creating an outlet directly to small intestine, by passing stomach

Gastric banding

Gastric band places on opening from esophagus to stomach to shrink/open/adjust opening

Weight loss strategies

Be realistic, provide less energy than needed, slow down when eating, good nutrtion, physical activity

Breakfast frequency

• People who dont eat breakfast tend to be obese

Fad diets

Lies, false claims, not backed scientifically