Hunger and Eating Disorders Flashcards

Key Ideas in the Physiology of Hunger

• Basic Understanding of Hunger: Hunger is not just a simple feeling; it's influenced by cognitive and physical factors.

• Physiological Triggers:

  • Stomach contractions: When your stomach growls, it sends signals to the brain indicating hunger.
  • Hormones:
    • Insulin: Secreted by the pancreas to lower blood glucose levels; promotes feelings of hunger when glucose supply is low.
    • Low blood sugar can lead to feelings of light-headedness, inability to focus, and shakiness.

• Brain's Role:

  • The hypothalamus monitors blood glucose levels using receptors in the stomach, liver, and intestines to signal hunger.

Hypothalamic Centers

• Lateral Hypothalamus:

  • Promotes feelings of hunger; if damaged, can lead to starvation as the individual will not know when to eat.
  • Remember: "Lateral = Let's eat."

• Ventromedial Hypothalamus:

  • Suppresses hunger; if damaged, can lead to uncontrollable eating, potentially resulting in severe health issues or death.
  • Think of this as: "ventromedial = vomit" (stops overeating).

Set Point Theory

• Understanding the Set Point:

  • Refers to a natural body weight that the body tends to maintain through adjusting food intake and energy expenditure.
  • If weight falls below set point, appetite increases; if above, appetite decreases.

• Metabolic Considerations:

  • The body adjusts its basal metabolic rate (resting energy expenditure) based on activity levels.
  • Not all researchers agree on the fixed nature of set points; some suggest lifestyle changes can alter them.

Psychological Factors Influencing Hunger

• External Incentives:

  • Presence of food can trigger hunger even when not physically hungry. E.g., social events with high-calorie foods.

• Eating by the Clock:

  • Regular meal times (like third bell in school) can create conditioned hunger regardless of actual need.

• Social Eating:

  • Obligations to eat when invited or pressured in social settings, even when not hungry.

• Stress and Depression:

  • Can alter eating habits, either increasing or decreasing appetite based on emotional state.

• Cultural Influence:

  • Cultural norms and expectations inform taste preferences and eating behaviors.

Taste Preferences

• Cultural vs. Biological Influences:
  • Different environments and cultures influence what foods we crave and enjoy.
  • Exposure to high-calorie foods can create a pattern of cravings aligned with cultural norms.

Eating Disorders

• Anorexia Nervosa:

  • Characterized by extreme weight loss in a person who perceives themselves as overweight.
  • Causes include genetic predispositions, social influences, and negative psychological factors.

• Bulimia Nervosa:

  • Involves binge eating followed by purging (vomiting, laxatives, etc.); often occurs in cycles.
  • Those affected may be of normal weight but struggle with self-image and cultural pressures.

• Binge Eating Disorder:

  • Similar to bulimia but without the purging behaviors; recurrent episodes of binge eating.

Body Image and Eating Disorders

• Cultural Influences:

  • Western cultures usually emphasize thinness, leading to higher rates of eating disorders.
  • Low self-esteem, particularly in women, can exacerbate negative body image and make one vulnerable to eating disorders.

• Demographics:

  • While eating disorders predominantly affect women, there is an increasing incidence among men and athletes.

Summary

• Hunger involves a complex interplay of biological, psychological, and social factors.
• Understanding these interactions is critical for addressing issues related to hunger and eating disorders.