NUTR module 7:Obesity and energy Balance

Exam 3 content

How to maintain weight?

Kcal Consumption = Kcal Expended

How to lose weight?

Kcal Consumption < Kcal Expended

How to gain weight?

Kcal consumption > Kcal Expended

Calories in

The food we eat

How can low-fat and fat-free products be deceiving?

Calories may be equal or greater than original product because they replace the calories from fat with carbs (sugar)

Portion and serving sizes have

gotten larger over time

Sugar sweetened beverages (SSBs)

One of the largest source of added sugar in the diet

Calories out

Energy expenditure

Total Energy Expenditure

Calories (or energy) expended in total

What are the three ways calories (or energy) is expended ?

• Resting Energy Expenditure (REE)

• Physical Activity

• Thermic Effect of Food (TEF)

Basic metabolic rate (BMR)

Energy metabolism that occurs after waking up, or 12 hours after last meal

BMR includes energy to sustain life including

• Breathing

• heart beat

• brain

• kidneys

• liver

Resting energy expenditure (REE)

Calories burned while sitting or sleeping; they make up most of the calories burned in a day

Physical activity

Voluntary physical activities, effort, exercise or labor

• Energy is needed for muscle contraction

What factors influence the amount of energy burned during exercise

• Body weight and muscle mass utilized

• Duration of activity

• Intensity of activity

• Fitness level

• Type of activity

-Lower intensity = the longer we can go and burn calories slower

- Higher intensity = can’t go as long and burn calories quicker

Thermic Effect of Food (TEF)

The process of burning calories as you digest, absorb, transport, store and metabolize food

What percent of calories consumed is burned from an average meal

10%

What can change the percentage of calories burned in the consumption of an average meal?

Protein—percentage is higher

How can you estimate energy expenditure?

• BMR

• Account for physical activity

BMR for women

665.1 + (9.563 x Weight in kg) +(1.85 x height in cm) - (4.676 x age)

BMR for men

66.5 + (13.75 x weight in kg) + (5.003 x height in cm) - (6.775 x age)

Body mass index (BMI)

Measure of weight relative to height. Often used to diagnose overweight/obesity

How do you calculate BMI

Weight in kg/(height in meters)²

Degree of excess fat for a healthy/normal weight

18.5 - 24.9

Degree of excess fat for someone overweight

25 - 29.5

Degree of excess fat for someone who is obese

over 30

Degree of excess fat for someone who is underweight

under 18.5

The BMI classifications are reflected in

• health outcomes

• Mortality

• other metrics

What is the connection between BMI and disease risk

Being overweight/obese (higher BMI) increases risk for a number of diseases

What are some diseases a higher BMI can lead to

• CVD

• Hypertension

• Type 2 diabetes

• stroke

• gallbladder disease

Are these disease associated with a higher BMI modifiable?

Yes, because it is a reflection of weight status which we can do something about

Mortality ratio for different BMI

• Low risk = healthy BMI (not 0, just lowest)

• higher risk = higher BMI

• increase mortality is exponential

• Increase in mortality = underweight as well

Negative consequences of being underweight

• Infertility

• Respiratory complications

• Heart irregularities

• Weak immune system

• Osteoporosis

Osteoporosis

A condition associated with decreased bone mass and bone density that can result in increased risk of bone fracture

Who is at risk for osteoporosis

• Elderly

• Women

• Underweight individuals

• Tobacco users

• Physical inactivity (low bone density (hormonally driven))

Limits of BMI on

• Athletes

• Various Ethnicities

• Sex

• Elderly

Individual vs larger scale for BMI

• BMI is more reflective on a larger scale/community

• On individual scale, BMI is flawed

Total body mass

Lean tissue mass + fat mass + water

What are the categories of body fat (different metabolic outcomes)

• Essential fat

• Storage fat

Essential fat

fat required for normal physiological functioning

Storage fat

fat in adipose tissue, tissue under the skin, and fat that “pads” essential organs

Percent of body fat differs with

Age and sex

Who has a higher body fat percentage ?

Women (for babies)

When does your metabolism start decreasing?

About the age of 65

When does your metabolism plummet (concerning starving yourself)

It stays the same for five days, on day six it increases and after that it starts to go down

*Nutrient timing doesn’t matter for weight management*

Unless for building muscle

Set point (theory)

Indicates that your body wants to keep you at a specific mass/weight because in doing so its easier for body to maintain homeostasis

• Defense against gaining or losing weight

• Eat to maintain muscle mass and then continue eating like that or else body will revert back to however you start eating again

• Feedback mechanisms (genes) can be exhausted going back and forth from losing and gaining weight making it harder to lose weight

Gynoid pattern

Fat over muscle and under skin at hips and thighs (Subcutaneous fat)

Females typically show

Gynoid in fat distribution (mostly in hips and thighs)

Android Pattern

Body fat can be stored under the abdominal muscle around the internal organs (Visceral fat)

Android pattern drives

metabolic disease (more in males)

Android pattern is associated with

increased risk for chronic conditions due to fat

• Diabetes

• CVD

• Cancers

Why is there a difference in how individuals carry their weight? (Gynoid (apple shape) vs Android (pear shape)) Stores fat in above vs below waist

Due to the presence or distribution of receptors

What receptor is disturbed (causing a difference in how individuals carry weight)?

Beta adrenergic and some alpha

What activates Beta adrenergic receptor

Adrenaline, noradrenaline, caffeine, cortisol

Where are the Beta adrenergic receptors absent?

area where we carry out fat: like abdominal area

Globesity

Obesity epidemic is not just an issue for US or other industrialized societies (across the world)

Why is obesity now an issue fro children as well (50%)

• Lack of recess in schools

• Comfort when coming home (snacks/foods/desserts)

Metabolic rebounding

cells were fat and then stop and then start again (Baby, to kid, to adolescent)

Early metabolic rebounding in

Children

Other factors affecting weight

• Psychological

• Physiological

• Lifestyle behaviors

• Social and economic

What are the causes of obesity

• Energetics

• Environment

• Genetics

• Hormone imbalance

Energetics (concerning obesity)

Cause by a positive energy balance resulting from: eating more calories than you burn

Environment (Concerning obesity)

• Infrastructure may not provide for individuals

  • We move less and eat more

  • As a society in US fast food is easily accessible and cars transport us instead of walking

• Social network is obese

  • Individual ideas of acceptable weight increases

  • Clothing sizes have increased

• Healthy, affordable food is hard to purchase in some areas

  • Food desert: Anything greater than a mile to something that provides fresh groceries

Genetics (concerning obesity)

• Obesity cannot be described by a genetic event

• Metabolism adjusts to ensure homeostasis (farmers to door dash)

• Set point theory

• Adipocytes: When a person gains weight in the form of fat, both the number and size of fat storing cells (fat storing cells, only one that can expand to three times its mass and still be able to turn back to original)

  • Chaining in size of cells

    • Increase: hypertrophy

    • Decrease: Atrophy

  • Changing the number of cells

    • Increase: hyperplasia

Hormone imbalance (concerning obesity)

• Regulated by hormonal feedback

• Leptin: hormone released by fat cells to signal the brain that the body has had enough to eat

Increases hunger

• Ghrelin

• Neuropeptide Y

  • Increases hunger

  • decreases anxiety

  • Decreases pain

Decreased hunger

• Leptin (comes from fat cells)

  • Increase satiety

  • increases energy expenditure

• GLP1(Ozempic) → secreted in small intestine and receptors all over body

  • Delay gastric emptying (improving transit time)

  • increase insulin function

  • decrease hunger

• Peptide YY

  • Y = tyrosine (So there’s two tyrosine)

  • decrease hunger

• Insulin

Decreased leptin

• Increased food intake

• decreased energy expenditure

Increased leptin

• Decreased food intake

• increased dingy expenditure

Hunger

The need to eat

• Triggered by low blood glucose and ow glycogen

Appetite

The desire to eat

• Triggered by sight/smell of food

Neuropeptide Y

Compound (neurotransmitter) that increases food intake and blood glucose levels, promoting the storage of energy in fat cells

Ghrelin (increased hunger)

A hunger stimulating hormone produced by cells lining the stomach when the stomach is empty

• After eating → decrease release

• Ghrelin increases with weight loss

Why don’t diets work

• Extreme

• Ignore a lot of necessary nutrients

• Adherence is the greatest effector of weight management (Commitment)

• “Good” or “Bad”

• We have to make changes that we can follow overtime

What works fro weight loss/management

• Promote small lifestyle changes and reduce portion size

• 20% of muscle is protein

Decrease calorie intake

• Balanced diet that incorporates all food groups

• costume more lean meat sources which can increase bodies cholesterol levels

How much physical activity should an individual be getting

• Moderate activity: 30 minutes 5 days a week

• Vigorous activity: 20 min per session

• Aerobic activity to bur calories

• Strength training to build muscle

Behavior (why we eat)

• Social and emotional cues

• Eating smaller meals does not increase metabolism but it does prevent you from over eating

Medication to treat obesity

• Recommended when a person is extremely obese or health complications

Candidates fro weight loss surgery

• BMI > 40kg/m²

• BMI > 35kg/m² + related health conditions

• At least 100 pounds overweight

Vertical Sleeve Gastrectomy

Removing a large portion of the stomach to feel full on much less food

• Restricted (small stomach = less room for food

• Not reversible

Adjustable gastric band procedure

Adjustable band fits around upper part of stomach

• Restriction

• Reversible

Roux-en-Y gastric bypass

Create a small pouch out of stomach and re route it to attach to area in small intestine

• Restriction

• Malabsorption

• Irreversible

Gastric balloons

• Reversible

• Insert balloons in stomach and fill them to take up spce in stomach to make you feel fuller

• Disruptive digestion

Issues that arise from these weight loss procedures

• Vertical gastric sleeve and Gastric bypass

  • issues handling and digesting protein and a vitamin B12 deficiency

• Might have overall nutrient deficiency if eating less overall (undernutrition)

• Gastric bypass

  • disruptive digestion

Treating childhood obesity

• Do not encourage calorie restriction beyond their maintenance needs

• Encourage them to be more active

• Let them grow into their weight