Chapter 15: Weight Management

Obesity in America

In the early 1960s, fewer than 32% of Americans were overweight, but currently, 67% of Americans are overweight, with over 33% of adults and 16% of children being obese.

Weight Management

The practice of maintaining body weight within a healthy range, typically defined as a BMI of 18.5 to 24.9, to reduce the risk of weight-related health problems or diseases.

Perception of Obesity

In 2013, the American Medical Association classified obesity as a disease, leading to clearer recognition of health risks, easier insurance coverage for treatment, and increased research funding.

Social and Psychological Risks

Overweight individuals may face discrimination, job limitations, and mental health issues like higher rates of suicide, while underweight individuals may experience irritability and depression.

Regulation of Food Intake

Appetite is the desire to eat food influenced by various factors, hunger is the physical need for food, and satiety is the feeling of fullness after eating.

Brain and Hormones in Hunger and Satiety

Satiety is controlled by the ventromedial nucleus and hormones like CKK, PYY, and leptin, while hunger is regulated by the lateral hypothalamus and hormones like ghrelin and neuropeptide Y.

Fat Cell Formation

Fat cells can expand through hypertrophy or increase in number through hyperplasia, with heavier individuals having increased LPL activity and fat growth continuing throughout life.

Genetic and Environmental Influences

Genetic factors like nutrigenomics and epigenetics interact with environmental factors such as modern lifestyles promoting weight gain, leading to obesity susceptibility and the need for healthy habits.

Healthful Weight Loss Strategies

Effective weight loss involves reasonable goals, balanced diet, physical activity, behavior modification, and maintenance strategies like energy gap reduction and self-monitoring.

Medical Interventions for Obesity

Extreme obesity may require weight-loss medications like Sibutramine or bariatric surgery options such as gastric bypass, with post-surgery care focusing on dietary changes and gradual weight loss.