Nutrition: Chapter 7, Weight Management

Lipoprotein lipase (LPL)
An enzyme that promotes fat storage in fat and muscle cells. Obese people generally have much higher amounts of LPL. This enzyme is mounted on the surface of fat cells that hydrolyzes triglycerides in the blood into fatty acid for absorption into the cells.
High LPL activity makes fat storage. . .
very efficient!
Leptin
A hormone produced by fat cells. A gene called the “obesity gene” is thought to code for this hormone.
What does leptin do?
It decreases appetite and increases energy expenditure.
What part of the brain does leptin affect?
The hypothalamus.
Hypothalamus
A brain center that controls activities such as maintenance of water balance, regulation of body temperature, and control of appetite.
Ghrelin
Another protein that has the opposite effect of leptin. It is a hormone produced by the stomach cells. It signals the brain to stimulate appetite and food intake.
Ghrelin is an extremely powerful. . .
Appetite stimulant.
Set-point Theory
Proposes that body weight, like body temperature, is physiologically regulated. The theory that the body tends to maintain a certain weight by means of its own controls.
Hunger
The physiological need to eat, experienced as a drive to obtain food; an unpleasant sensation that demands relief. Hunger is a drive programmed into people by their heredity.
Appetite
The PSYCHOLOGICAL desire to eat. It is a LEARNED motivation that is experienced as a pleasant sensation that accompanies the sight, smell, or thought of appealing foods.
Satiation
The feeling of satisfaction and fullness that occurs during a meal and halts eating. It determines how much food is consumed during a meal.
Satiety
The feeling of fullness and satisfaction that occurs after a meal and INHIBITS eating until the next meal. Satiety determines how much time passes between meals.
Difference between satiation vs. satiety
Satiation tells us when to STOP eating, whereas satiety tells us to “not start eating again”.
Screen time
Sedentary time spent using an electronic device, such as a television, computer, or video game. It has replaced outdoor activities for many people.
Built environment
The buildings, roads, utilities, homes, fixtures, parks, and all other manufactured entities that form the physical characteristics of a community.
Food deserts
Urban and rural low-income areas with limited access to affordable and nutritious foods. Instead, most of their food comes from fast-food places and local convenience stores where refined packaged foods are in abundance and cheap.
Ephedra (Ephedrine)
An herb that showed promise as a weight-loss drug in studies. However, it showed ill-effects including cardiac arrest, abnormal heartbeats, hypertension, and seizures. Ephedra is now banned in the US
Where is Ephedra extracted from?
It is an amphetamine-like substance extracted from the Chinese herb ma huang.
Clinically severe obesity
A BMI of 40 or greater, or a BMI of 35 or greater with one or more serious conditions such as hypertension. Another term used to describe the same condition is “morbid obesity”.
Most effective treatment for morbidly obese people is:
Surgery (two kinds): gastric bypass surgeyr and gastric banding.
Gastric bypass
Surgery that restricts stomach size and reroutes food from the stomach to the lower part of the small intestine. Creates a chronic, lifelong state of malabsorption by preventing normal digestion and absorption of nutrients.
Gastric banding
A surgical means of producing weight loss by restricting stomach size with a constricting band.
Laparoscopic weight-loss surgery
A weight-loss surgery procedure in which surgeons gain access to the abdomen via several small incisions. A tiny video camera is inserted through one of the incisions and surgical instruments through the others. The surgeons watch their work on a large-screen monitor. Wow!
Resistance training
The use of free weights or weight machines to provide resistance for developing muscle strength, power, and endurance; also called weight training. A person’s own body weight can be used to do push-ups, pull-ups, crunches, etc.
Behavior modification
The changing of behavior by the manipulation of antecedents (cues or environmental factors that trigger behavior), the behavior itself, and the consequences (the penalties or rewards attached to behavior).
Cognitive skills
“New ways of thinking” to help overweight people solve problems and correct false thinking that can undermine healthy eating behaviors. Changes to conscious thoughts with the goal of improving to lifestyle modifications.
Self-efficacy
A person’s belief in his or her ability to succeed in something.
Lapses
Periods or returning to old habits.
Two causes of obesity in humans are:
Genetics and physical inactivity
The protein produced by the fat cells under the direction of the ob or “obesity” gene is called:
Leptin
What describes the behavior of fat cells?
1) The storage capacity for fat depends on both cell number and size
2) The size is larger in obese people that in normal-weight people
3) The number increases most rapidly during the growth years and tapers off when adult status is reached
The obesity theory that suggests the body chooses to be at a specific weight is called the:
Set-point theory
The biggest problem associated with the use of prescription drugs in the treatment of obesity is:
The necessity for long-term use
A nutritionally sound weight-loss diet might restrict daily energy intake to create a:
500-kcalorie per day deficit
What is the best approach to weight loss?
Reduce daily energy intake, and increase energy expenditure
Physical activity does NOT help a person to. . .
Lose fat in trouble spots
Suggestions to change behaviors for successful weight control include:
Learn appropriate portion sizes
What strategy would NOT help an underweight person to gain weight?
Drink plenty of water