Motivation to Eat

1
Motivation to Eat

• Michelle Deming
  Karin Kassab
• Johan Icard
  Charlotte Leuth

2
Hunger and Eating Based on Biology

• Stomach Contraction Theory We know when we are
  hungry when our stomach contracts (Cannon and
  Washburn 1995). (Balloon Study)
• Later opposed when it was discovered that people
  whose stomachs were removed still felt hungry.
• The glucose theory states that we feel hungry
  when our blood glucose level is low. (Bash,
  1994).
• The Insulin theory states that we feel hungry
  when our insulin level increases suddenly in our
  bodies (Heller Heller, 1991).
• The Fatty Acid theory states that our body has
  receptors that detect an increase in the level of
  fatty acid. Activation of the receptor for fatty
  acid triggers hunger (Dole, 1956, Klein et al.,
  1960, cited in Franklin, 1994).
• Heat-Production theory states that we feel hungry
  when our body temperature drops, and when it
  rises, the hunger decreases. (as cited in
  Franklin, 1994).

3
The Biological Basis

• It is an intricate feedback system in which
  energy expenditure and food intake are balanced.
  The brain responds to hormonal signals that
  maintain body weight by telling us when to start
  and stop eating and how much to consume. One
  central player is leptin, a hormone produced by
  fat cells in the stomach, which suppresses
  appetite and stimulates energy expenditure. Other
  weight-regulating hormones are ghrelin (an
  appetite stimulant), insulin, the orexins, and
  cholecystokinin. The neurotransmitters serotonin,
  norepinephrine, and dopamine are also involved.
  When fat stores diminish, hunger increases and
  metabolic processes slow down to use energy more
  efficiently.

4
The Biological Basis, continued

• The system is remarkably accurate, but over a
  lifetime even a slight imbalance adds up. To gain
  a pound a year, an adult need eat only an extra
  10 or 20 calories a day. How much it takes
  depends partly on heredity. Weight is as
  heritable as height, and nearly two dozen genes
  are known to control the production of
  weight-regulating hormones. Heavier people do not
  necessarily eat more than average, and they are
  not necessarily less active. There is evidence
  that the obese have congenitally low sensitivity
  to leptin. Experiments on mice suggest that
  individual variation in the tendency to gain
  weight may depend on the action of
  weight-regulating hormones during early
  development.

5
Hunger and Eating Based on Learning

• Humans use an external clock in daily routines,
  including when to sleep and when to eat. This
  external time triggers hunger. (learned behavior)
• Taste, smell, or texture of food also triggers
  hunger. These preferences are culturally learned.

6
Hunger Based in Environment

• Many environmental factors influence hunger,
  including the availability of rich foods, taste
  preferences, habits, memory, stress, and cultural
  attitudes
• Availability of rich foods People tend to gain
  weight when rich foods are plentiful.
• Preferences Some taste preferences appear to be
  innate, such as the preference for fatty foods.
  However, people acquire most taste preferences
  through conditioning or observational learning.
  People tend to prefer familiar foods. These
  preferences have an influence on hunger and food
  intake.
• Habits People learn habits, such as when and how
  much they eat. These habits also influence hunger
  and food intake.
• Memory The memory of what people last ate and
  when they ate it influences hunger.
• Stress The increased physiological arousal
  associated with stressful situations can
  stimulate hunger in some people. In other people,
  stress decreases hunger.
• Cultural attitudes Cultural attitudes about
  ideal body size and shape have a strong influence
  on what and how much people eat.

7
Environmental and Social Factors

• Social factors including poverty and a lower
  level of education have been linked to obesity.
  One reason for this may be that high-calorie
  processed foods cost less and are easier to find
  and prepare than healthier foods, such as fresh
  vegetables and fruits. Other reasons may include
  inadequate access to safe recreation places or
  the cost of gym memberships, limiting
  opportunities for physical activity. However, the
  link between low socio-economic status and
  obesity has not been conclusively established,
  and recent research shows that obesity is also
  increasing among high-income groups.

8
Hunger and Eating Based on Cognition

• Colors also contribute to hunger.
• For example, looking at a yellow banana makes one
  to want to eat it, but a red banana does not.
  Similarly, red or green can trigger hunger for an
  apple, but not blue. It is hard to find natural
  food with blue color, because mother nature does
  not produce blue food. Blue is said to be an
  appetite suppressant.
• In addition, many people eat foods base on their
  knowledge of what foods are good for them. For
  example, low fat, low sugar, and low sodium food
  are said to be good. Eventually people learn to
  change their preference and want to eat "good
  food" only (Franken, 1994).

9
Mind and Body Connection of Hunger

• Hunger is a primary motivation. Despite strong
  beliefs that hunger is caused biologically, this
  motivation is controlled not just by physiology,
  but also psychology as well.
• There are two kinds of hungers one is caused
  physiologically, and the other is caused
  psychologically. What makes human beings
  different from animals is that we eat not only to
  feed our bodies to satiate physiological hunger,
  but also to feed our minds to satiate
  psychological hunger as well.
• Problems like eating disorders and obesity could
  occur because we mistakenly keep tying to satiate
  our psychological hunger by eating food. Thus,
  hunger is not only about how the body changes
  physiologically, it is about how our body and
  mind together are well fed, not just by the food
  that one can put in their mouth, but also by the
  whole environment around us (Hara, 1997).

10
Motivations Behind Eating

• The consumption of food is a basic daily activity
  for most however, for some, this vital need is
  clouded by physical and emotional turmoil. In the
  following slides, we will explore an array of
  normal and problematic behaviors associated with
  eating in America in this day and age.

11
Anorexia Nervosa

• Defined by http//www.yourmentalhealthinfo.com/eat
  ing_disorder.htm as, An eating disorder that
  causes extreme weight loss due to starvation. 
  This eating disorder can affect anyone at any
  age, but it mostly occurs in young women.
  Anorexia symptoms include an intense concern with
  weight, not eating to control weight, and no
  regard for physical and mental health.

12
Anorexia Statistics

• Research suggests that approximately one percent
  (1) of female adolescents suffer from anorexia
  (ANRED Anorexia Nervosa and Related Eating
  Disorders).
• Females are known to struggle with anorexia more
  commonly than males, with statistics showing only
  10 of all anorexia and bulimia sufferers as male
  (ANRED).

13
Anorexia Some Basic Facts

• Most anorexics appear excessively thin and
  emaciated to the average person.
• The anorexic is concerned with both appearance
  and control and these tend to be the main
  motivations behind the development of the
  disorder. Research shows than many young women
  resort to anorexia as a way of gaining control
  over their weight when they can not gain control
  over anything else in life.
• Anorexics may know that they have a problem and
  be motivated to get better, but they are hindered
  when they look in the mirror and still feel they
  are too big.
• Many anorexics are known to be perfectionists as
  well, which supports the notion that they feel
  like they are never good enough and never thin
  enough.
• Sufferers are known to keep their disorder
  hidden, as not to attract unwanted attention,
  which may force them to seek treatment.
• Anorexia can be connected to obsessive-compulsive
  behaviors because the anorexic is constantly
  thinking (obsessing) and acting (compulsions) in
  ways that center around weight and food.
• All information on this page came from
  http//www.calorierestriction.org/CR_vs_Anorexia

14
Bulimia Nervosa

• Defined by http//www.medterms.com/script/main/ar
  t.asp?articlekey2546 as, An eating disorder
  characterized by episodes of secretive excessive
  eating (binge-eating) followed by inappropriate
  methods of weight control, such as self-induced
  vomiting (purging), abuse of laxatives and
  diuretics, or excessive exercise. The insatiable
  appetite of bulimia is often interrupted by
  periods of anorexia

15
Bulimia Statistics

• Research suggests that approximately four percent
  (4) of all college aged women suffer from
  bulimia (ANRED).
• About 50 of those who have anorexia will go on
  to develop bulimic tendencies as well (ANRED).
• Like anorexia, bulimia is much less common in
  males. Males make up about 10 of the total
  population of anorexia and bulimia sufferers
  combined (ANRED).

16
Bulimia Some Basic Facts

• Bulimics tend to be of average weight some are
  even characterized as being slightly chubby.
• Many bulimics are known to have impulse-control
  problems (hence the binge eating that occurs with
  the disorder), as well as anxiety and depression
  problems.
• Bulimia sufferers tend to try to take on more
  than they can handle within their daily lives
  (activities, responsibilities, relationships,
  etc.) and then fall short of expectations (either
  their own or others). Generally, binge eating is
  a coping mechanism for the bulimic, who
  immediately feels the need to purge out of guilt
  afterwards.
• Bulimics hide their behaviors just as anorexics
  do. They binge when they are completely alone
  there is no danger of being interrupted. If they
  are interrupted, they will immediately stop and
  attempt to cover their tracks.
• Genetic factors contribute to both anorexia and
  bulimia, but the exact role that genes play is
  yet to be determined.
• Information on this page provided by
  http//www.anred.com/index.html

17
Calorie Restriction

• Calorie Restriction (abbreviated as CR) is a
  relatively new phenomenon in which people
  restrict their daily caloric intake in order to
  live healthier and longer lives.
• Calorierestriction.org says the following about
  CR, The goal of Calorie Restriction is to
  achieve a longer and healthier life by eating
  fewer calories, and consuming adequate vitamins,
  minerals, and other essential nutrients.

18
CR versus Anorexia

• Since CR is a relatively drastic lifestyle change
  for most people, it has been accused of being a
  slightly less problematic version of anorexia.
• Calorierestriction.org maintains that CR has very
  little in common with anorexia, claiming that the
  motivations behind CR are to live longer and
  healthier lives, while anorexics have no regard
  for health.

19
Calorie Restriction Some Basic Facts

• Unlike anorexia, bulimia, and most other types of
  disordered eating, CR is done out in the open it
  is not hidden.
• Those who practice CR view their lifestyle as
  good and healthy.
• CR allows cheating without guilt. For example,
  eating a piece of cake on ones birthday is
  considered fine and is not to be seen as failure.
• CR requires the acceptance of oneself - and the
  act of eating -- as imperfect.
  (calorierestriction.org)
• While the anorexic tends to view food as the
  enemy, the CR practitioner regards food highly,
  as life-sustaining and healthy.
• Perhaps the largest difference between CR and
  anorexia is the fact that CR is not about weight
  or appearance, it is about health and longevity.
  Anorexia is about control and body image.
• Video http//www.cbsnews.com/stories/2005/12/30/e
  veningnews/main1172297.shtml

20
Orthorexia Nervosa

• Some doctors think othorexia is just a
  manifestation from OCD centered around food.
• Dr. Steven Bratman is the man credited with
  discovering orthorexia nervosa or at least
  classifying it as a disorder in 1997.
• It is a pathological and unhealthy obsession for
  a strict, pure, and healthy diet. These people
  build a diet by excluding foods with herbicides,
  pesticides, or artificial substances. They spend
  a lot of time worrying about these foods if they
  consume them and then it will cause depression.
  Social relationships are lost because this
  obsession with their diet becomes the most
  important part of their life. Many people with
  orthorexia will not eat food prepared by their
  parents or friends or anyone else they trust,
  even if they are starving. A lot of times they
  will lose a lot of weight as well and be mistaken
  for having anorexia

21
Orthorexia Nervosa, continued

• These disorders are usually worked out, but there
  was a case in December of 2003 where woman named
  Kate Finn died from heart failure shortly after
  recovering from orthorexia.
• Symptoms include the obsession with healthy
  eating or even starving. Those who suffer from
  orthorexia tend to have an uncontrollable desire
  to eat when feeling guilty, nervous, happy, or
  excited.
• It is long term or it wouldn't be orthorexia it
  would just be a diet plan. But it is abnormal to
  continue obsessing about these foods after
  reaching your desired weight, which is what
  sufferers from orthorexia do.
• The big difference between othorexia and anorexia
  is that anorexic people obsess on the quantity of
  food they take in where as orthorexic people
  obsess over quality.

22
Bigorexia (Muscle Mania)

• Bigorexia or muscular dysmorphia was also named
  so in 1997 and is commonly referred to as
  reverse anorexia. It is usually a subtype of
  OCD, depression, or Body Dysmorphic Disorder.
  Almost all of them suffer from depression as well
  and develop this from trying to counteract or
  ignore their depression. Whats worse?
• It is their brain which cant seem to map out
  their bodys boundaries.
• Most of the men and women with this disorder are
  weightlifters even though many are still shy to
  show their bodies off. They will also skip work
  or other important events to continue building
  their physique and will even work through
  injuries and broken bones.
• Strict diets are key in bigorexia. Many men wont
  eat out because of their diets. Instead they
  carry their calorie filled snacks with them
  wherever they go to obtain the required 4000-5000
  daily. But some develop bulimia from their
  dieting.
• They have a distorted body image, thinking they
  are smaller than the next man when in actuality
  they are a lot bigger.

23
Bigorexia, continued

• Men with bigorexia often use steroids to help
  reach their desired physique and they will
  continue to use steroids through their side
  effects which include increased aggression, acne,
  breast growth, balding, impotence, and testicular
  shrinkage.
• Causes are most likely from pressure from society
  for men to look muscular and lean.
• These people are more concerned with body fat
  percentage and not being overweight, which is one
  big difference from other eating disorders.
• However, bigorexia is under-diagnosed since it is
  acceptable in our society for men to look so huge
  and most assume they are no other than the
  average, healthy bodybuilder.
• A study of 1000 men showed that about forty
  percent would consider chest implants

24
Pica

• Pica is defined as a compulsive craving for
  eating , chewing, or licking non-food items or
  food containing no nutrition.
• These may include but are not limited to such
  things as chalk, plaster, paint, chips, baking
  soda, starch, glue, rust, ice, coffee grounds,
  and cigarette ashes.
• Current populations at high risk include young
  children, pregnant women, developmentally delayed
  individuals, psychiatric and mentally disables
  individuals, low SES, individual who live in the
  Southeastern U.S., stressed individuals, and
  individuals with a family history of pica.
• Pica and its causes remain controversial.
  Published theories range from nutritional ,
  sensory, neuro-psychiatric and psychosocial to
  cultural.

25
Rumination

• Rumination is defined as the voluntary or
  involuntary regurgitation and rechewing of
  partially digested food that is either
  reswallowed or expelled.
• The behavior must exists for at least one moth
  with evidence of normal functioning prior to
  onset. Frequency may vary, but typically occurs
  daily and may persist for months or years.
• The onset is usually within the first year of
  life but rumination among adolescents and adults
  with normal intelligence is gaining increased
  recognition.
• Although the etiology of rumination is unknown,
  cultural, SES, organic, and psychodynamic factors
  have been implicated

26
United States Obesity Timeline

• http//health.msn.com/reports/obesity/default.aspx
  ?GT18307//health.msn.com/reports/obesity/default.
  aspx?GT18307

27
OBESITY Definitions

• 60 percent of adult Americans weigh too much, and
  17 percent of American children and teens are
  overweight or obese, too. Overweight is defined
  as having a body mass index (BMI) of between 25
  and 29.9, and obese as having a BMI of 30 or
  higher.
• "Obesity" specifically refers to an excessive
  amount of body fat.
• "Overweight" refers to an excessive amount of
  body weight that includes muscle, bone, fat, and
  water.

28
BMI information

• women have more body fat than men. Most health
  care professionals agree that men with more than
  25 percent body fat and women with more than 30
  percent body fat are obese. These numbers should
  not be confused with the body mass index (BMI),
  however, which is more commonly used by health
  care professionals to determine the effect of
  body weight on the risk for some diseases
• The BMI is a tool used to assess overweight and
  obesity and monitor changes in body weight. Like
  the weight-for-height tables, BMI has its
  limitations because it does not measure body fat
  or muscle directly. It is calculated by dividing
  a person's weight in pounds by height in inches
  squared and multiplied by 703.

29
Why is obesity such a problem?

• There is mounting evidence that shows lack of
  access to healthy food is associated with
  obesity, says MSN Health Fitness Nutrition
  Expert Keecha Harris. Harris is president of
  Harris and Associates, a food systems and
  public-health consulting firm based in
  Birmingham, Ala.

30
Does money play a role?

• Scientists are studying the relationship between
  economic status and weight. The Journal of
  American Medical Association published a study in
  May 2006 from researchers at Johns Hopkins
  University indicating that teenagers who are
  living at or below the poverty line show a
  greater prevalence of being overweight than
  teenagers who do not live in economically
  depressed areas.

31
Some other factors

• MSNs Weight Loss and Fitness Expert Martica
  Heaner, an exercise physiologist and
  nutritionist, explains that while the rate of
  obesity is growing everywhere, obesity may affect
  more Americans in areas where driving is a must
  because of urban sprawl, or in very rural parts
  of America.

32
By Harvard Health Publications

• At one time it was commonly believed that
  overweight and obese people were compulsive
  eaters, anxious, depressed, under stress, or
  trying to compensate for inadequate upbringing,
  family conflict, or other deficiencies in their
  lives. But since then, when almost everyone seems
  to be getting heavier and obesity has become a
  national political issue, both experts and the
  public are turning away from the idea that weight
  gain is a personal emotional problem. Instead the
  trend toward obesity has become a subject for
  biologists and sociologists, regarded as the
  physical consequence of a general social
  condition.

33
Abundance and Frustration

• The average American weighs 7 to 10 pounds more
  in 2004 than in 1990.
• The name of the self-help group Overeaters
  Anonymous proclaims an analogy between overeating
  and addiction to alcohol or drugs. Some
  scientists who investigate food cravings take
  that idea seriously. Brain scans and animal
  experiments are suggesting that some of the same
  brain centers are active in both food addiction
  and drug addiction. And the same social changes
  may be involved as well. The industrial
  revolution that has provided some parts of the
  world with abundant, highly processed,
  easy-to-eat food is also loosing a flood of
  chemically pure injectable drugs of abuse.

34
Mental Health and Weight

• The American Psychiatric Association has never
  regarded overeating or excess weight as a
  psychiatric disorder, and most obese people do
  not qualify for a psychiatric diagnosis. Most
  studies find no clear association between mental
  health and weight. In a review of 16 studies, 6
  found that obese people were more mentally
  healthy than average, 7 found them to be less
  mentally healthy than average, and 3 found no
  difference. Some studies link depression or
  behavior problems with obesity in children, but
  the evidence is incomplete and inconsistent,
  especially after taking account of their parents
  emotional problems.
• Some research suggests that depressed persons are
  more likely to develop a metabolic syndrome
  (insulin resistance, high blood pressure, excess
  abdominal fat, high cholesterol) that often
  accompanies excess weight, especially when it is
  deposited around the waist. In a survey of 40,000
  Americans, high body weight was associated with
  symptoms of depression in women, although not in
  men.

35
Mental Health and Weight, continued

• Research in mice and humans suggests that food
  high in fat, sugar, and calories lowers the
  bodys response to chronic stress. In animal
  experiments, weight loss activates the stress
  response. People may console themselves with
  "comfort food" because they are anxious, lonely,
  angry, or suffering from low self-esteem. There
  is a characteristic type of depression with
  symptoms that include lethargy and overeating.
• Obesity can lead to ill health, which is linked
  to depression and anxiety. Overweight people are
  also more likely to lose the psychological
  benefits of exercise. If they feel rejected as
  unattractive or suffer social discrimination, the
  further emotional strain may cause further weight
  gain. The problem is worse if they fail to lose
  weight and are blamed (or blame themselves) for
  lack of self-control. (Some believe anorexia
  nervosa seemingly voluntary self-starvation
  is the out-of-control result of an attempt to
  demonstrate a capacity for self-control.)

36
Binge Eating

• There is one potential psychiatric diagnosis that
  is closely related to obesity, even if it is only
  "proposed for further study." In the American
  Psychiatric Associations Diagnostic Manual,
  binge eating disorder is tentatively defined as a
  condition that involves at least three of the
  following symptoms occurring at least twice a
  week for six months eating very fast, eating
  until uncomfortably full, eating when not hungry,
  eating alone, and feeling disgusted or guilty
  after eating. Its distinguished from bulimia by
  the absence of fasting, exercise, or vomiting to
  compensate.

37
Binge Eating, continued

• As many as 5 of Americans may be binge eaters at
  some time in their lives, including nearly half
  of the people enrolled in commercial weight-loss
  programs. Like body weight, binge eating disorder
  is highly heritable a Norwegian twin study found
  that 40 of individual differences in
  susceptibility had a genetic basis. Binge eating
  is associated with depression and even more
  strongly with anxiety disorders, including panic
  disorder, obsessive-compulsive disorder, and
  post-traumatic stress disorder.
• In July of 2004, the statement that "obesity
  itself cannot be considered an illness" was
  removed from the Medicare manual, opening the way
  to insurance coverage of any treatment that is
  proved to be effective. The change will stimulate
  research, including studies of behavioral and
  psychological counseling as well as diet and
  exercise programs and gastric bypass surgery. In
  the weight wars, depression, anxiety, and low
  self-esteem deserve attention even if they
  represent only a small part of a big problem.

38
Harvard Health Publications

• Obesity is not a new problem. Forty years ago, 4
  of every 10 Americans were overweight or obese.
  But obesity is a growing problem, and its
  growing quickly today, two of every three
  Americans need to lose weight. In the 1960s,
  obesity was an epidemic today, its a pandemic

39
The Facts

• Obesity is a major cause of premature death. The
  damage is evident in all age groups and with all
  degrees of overweight, but the toll is heaviest
  in the heaviest people, and obesity has a greater
  impact the earlier it occurs. For example, a very
  obese 25-year-old man can expect to lose 13 years
  of life 22 of his life expectancy due to
  obesity. A 40-year-old man who is simply
  overweight may lose more than three years of
  life, but a 40-year-old man who is obese may lose
  nearly six years. All in all, obesity and lack of
  exercise are responsible for about 1,000 deaths
  in the United States every day. And if present
  trends continue, obesity will soon overtake
  smoking as the leading preventable cause of death
  in America (it is already responsible for a
  poorer overall health-related quality of life
  than smoking).

40
Obesity as a function of calories

• A 2004 study proved the proposition Americans
  are eating more. Researchers at the Centers for
  Disease Control and Prevention evaluated the
  caloric consumption of average Americans between
  1971 and 2000. For men, the average daily
  consumption increased from 2,450 to 2,618
  calories. Thats a jump of 168 calories a day. It
  may not seem like much, but over the course of a
  year it will add 17 pounds and the news is even
  worse for women, who added 335 calories a day
  over the 30-year span.

41
Other Causes of Obesity

• Some illnesses may lead to or are associated
  with weight gain or obesity. These include
• Hypothyroidism, a condition in which the thyroid
  gland fails to produce enough thyroid hormone. It
  often results in lowered metabolic rate and loss
  of vigor.
• Cushing's syndrome, a hormonal disorder caused by
  prolonged exposure of the body's tissues to high
  levels of the hormone cortisol. Symptoms vary,
  but most people have upper body obesity, rounded
  face, increased fat around the neck, and thinning
  arms and legs.
• Polycystic ovary syndrome, a condition
  characterized by high levels of androgens (male
  hormone), irregular or missed menstrual cycles,
  and in some cases, multiple small cysts in the
  ovaries. Cysts are fluid-filled sacs.

42
Discrimination

• In concordance with a number of other societal
  factors, Brownell claims the media has managed to
  create a relatively limited and notorious
  stereotype of the obese person lazy, unmotivated
  and uncontrolled. On the contrary, according to
  tolerance.org, their attractive and slimmer
  counterparts evoke feelings of skill, popularity,
  intelligence and happiness. The message the media
  sends is clear thin is good, fat is bad.
• Weight discrimination is one of the leading
  prejudices in our society the emotional and
  psychological effects of this can lead to
  continued eating and depression.