Chapter 15: Weight managment

What % of Americans are overweight?

67%

• 33% in adults

• 16% in children

What is a healthy weight?

A weight that does NOT increase risk for developing weight-related health problems or diseases

• healthy weight lowers risk for chronic disease

Individuals who are underweight are more likely to be at greater risk for…?

• irritability

• anger

• depression

Appetite

the desire to eat food whether or not there is physical hunger

• Psychological

• triggered by factors such as time of day, social occasions, emotions

Hunger

The physical sensations assoc. with the need or intense desire for food

• physical need (Ghrelin release, etc)

Satiety

The feeling of “fullness” produced by the consumption of food

what controls feeding?

brain and hormones

Satiety is triggered by what part of the brain?

Hypothalamus (the ventromedial nucleus)

• CKK and PYY is secreted by the small intestine to stimulate satiety

Leptin

• produced in adipose tissue

• decreases hunger and food intake

• regulates amount of fat stored

• decreases with weight loss and intake of certain vitamins and minerals

Hunger is controlled by what part of the brain

Lateral Hypothalamus

• Ghrelin: secreted by the stomach

• increased production tells hypothalamus the body needs energy

• stimulates hunger during fasting or on a low kcals diet

• lean individual have higher ghrelin levels

Neuropeptide Y

Produced in the hypothalamus and activated by Ghrelin

• stimulates hunger and LPL activity

Growth of fat cells occur in 2 ways?

1. Hypertrophy

2. Hyperplasia

Hypertrophy

• Can expand to store more fat

Hyperplasia

Once filled to capacity, stimulate the production of more fat cells

• slows with age

T or F: adipocyte cells die with weight loss

F

• adipocytes shrink in size with weight loss but the # of cells DOES NOT decrease

What enzymes control the size of fat cells

• Lipoprotein lipase (LPL) increases lipogenesis

• Hormone-sensitive lipase (HSL) stimulated lipolysis “pulling out”

Nutrigenomics

The study of how your genetic makeup interacts with your diets

Epigenetics

The changes that may occur in gene activity and gene expression without altering DNA sequence

__and __ are believed to affect how ppl respond to food intake.

Epigenetic alteration and Single-nucleotide polymorphism (SNP) are believed to affect how ppl respond to food intake

Adipocytes secrete the hormone …

Adiponectin

• improves the body’s response to insulin

• reduces fat accumulation in the liver and muscle

• Enhances energy expenditure

• Lower in obese individuals and Type II diabetics than lean ppl

Genetic “set point” theory

• Body fights to remain at a specific body weight and poopses attempts at weight loss

• given the rapid rise in weight gain, this theory doesn’t have enough info

How can you lose weight healthfully?

• modify diet

• physical activity: 60-90 mins

• behavior

• choose lower kcals

• eat more volume foods

• eat more veggies, fruit and fiber

• avoid mindless eating

• add protein and fat to meals

• myplate

Energy-gap reduction

• Helps maintain weight loss/ successful weight maintainers

• reduce kcals intake by decreasing portions and fatty foods

• eat smaller, more frequent meals

• maintain high level of physical activity

Healthiest way to gain weight

• Add 500 kcals to daily energy intake

• choose more energy dense foods

• include regular and resistance training

Semaglutide

Ozempic

• GLP-1 receptor agonist

• supresses appetite

Orlistat

Xenical

• inhibits fat absorption

Lorcaserin

Belviq

• stimulates satiety and may reduce food intake

Gastric bypass surgery

• Stomach is closed off and a small pouch is left that can hold ¼ of a cup at a time

Post surgery:

• Consume small/ frequent meals

Weight loss:

• 5-15 lbs per week in first 2-3 mo.

Eliminates:

• Diabetes

• Hypertension

Gastric banding

• Weight loss is slower compared to gastric bypass surgery

• banding is less invasive

FAD diets

• promise quick weight loss by unproven/ unhealthy means

• a specific macro is targeted and severely restricted

• supplements must be taken

• overly restrictive

Reasonable rate of weight loss

• 10% of body weight over 6 mo.