Regulation of Body Weight and Food Intake Flashcards Preview

DEMS Unit 2 Part 2 > Regulation of Body Weight and Food Intake > Flashcards

Flashcards in Regulation of Body Weight and Food Intake Deck (15):
1

Energy Balance or Homeostasis

Food & Caloric Beverage intake = Activity + digestion + BMR

2

Potential mechanisms to adapt to the environment

1 .Genetics
2. Increased Energy Expenditure (REE, TEF, Activity)
3. Reduced intake/appetite
4. Changes in substrate metabolism

3

Evidence of a set-point

Rats fed a chow diet and then either calorie restricted or overfed. They all come back to a baseline

4

Energy Balance Regulation

Physiologic or Homeostatic Mechanisms:
- Short-Term Signals = meal related
- Long-Term Signals = adiposity-related

Non-homeostatic Mechanisms:
- Reward and motivation
- Cognitive/Executive decisions
- Environmental Cues
- Social context

5

Catabolic vs. Anabolic pathways

Anabolic = eat more
Catabolic = stop eating

6

Hypothalamus - Hunger center and satiety center

Lateral Nucleus - if you erode this, the rat stops eating; hunger center

Ventromedial nucleus - If you erode this, they can't stop eating; this is the satiety center

7

Leptin

Hormone signal associated with stimulating catabolic pathways and inhibiting anabolic pathways

8

NPY

Anabolic
- increase food intake
- decrease energy expenditure

Release AgRP (agouti related peptide) to inhibit the catabolic pathway

9

POMC

Catabolic
- decrease food intake
- increase energy expenditure

10

Meal to meal regulation hormones

Ghrelin and PYY

Ghrelin - from stomach (anabolic, stimulate apetite; highest before you eat - hunger hormone)
PYY- from distal ileum (catabolic, rise after a meal, satiety hormones)

11

People who are obese prone have high levels of ____ but have the same amount of hunger

Leptin

Are they leptin resistant?

12

Do obese people have more ghrelin or PYY?

No. PYY is about the same and underfed people have more ghrelin

13

Problems with our biologic or homeostatic regulation of food intake

- Maybe designed to protect during undernutrition
- Maybe resistance to signals like leptin

14

Non-homeostatic regulation of energy intake

Internal inputs:
- Reward mechanisms
- Cravings
- Thinking about food
- Restraint
- Learned behaviors
- Attention

External inputs:
- Environmental cues (sight, smell, taste)
- Availability/Portions
- Social context
- Time cues

15

What parts of the brains light up with food?

- Attention
- Reward
- Motivation
- Memory

Obese prone people have persistent activity in these areas