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Chapter 11: Water and the Major Minerals

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Title: Chapter 11: Water and the Major Minerals


1
10 Outline for today
  • Obesity
  • Finish set-point theory
  • Types of obesity
  • Weight loss diets
  • Recommendations for weight loss
  • Where to Get Reliable Nutrition Information
  • Next time ?
  • Anorexia, bulimia etc.
  • How to determine if what you read and hear is
    credible

2
Recap of last lecture
  • Fasting
  • Energy reserves
  • Metabolic adaptation
  • Order of loss of body proteins
  • Set Point Theory

3
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4
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5
Where to Get Reliable Nutrition Information
6
Eat all you want!" "Watch the fat disappear!"
"Block the starch and lose weight!"
  • These and other similar weight loss claims for
    some dietary supplements can cause "unfounded
    hope" and must be removed from Web sites that use
    them, the Food and Drug Administration warned
    Thursday, April 1. The agency said it sent
    warning letters to 16 Web sites that promoted
    certain products as blocking carbohydrates,
    starch and calories from fat without noting the
    need to make lifestyle changes, like exercising
    or eating a healthy diet.


7
Susanne Somers' Get Skinny on Fabulous Food, by
Suzanne Somers
  • Before she began penning diet books, the only
    remotely health-related entry on Suzanne Somers'
    resume was an infomercial for a thigh exerciser.
    She brings no nutrition credentials to bear on
    this book, which blames excess fat on the
    tendency of the body's enzymes to "cancel each
    other out." Her solution, a Byzantine process of
    eliminating "Funky Foods" and separating the rest
    into "Somersized Food Groups" for mixing and
    matching, has no nutritional basis.
  • Somers maintains that when proteins and
    carbohydrates are eaten together, their enzymes
    "cancel each other out," creating a halt in the
    digestion process and causing weight gain.
  • Unfortunately, this reasoning is based on
    assumptions that are completely false. In fact,
    the body contains enzymes that are specifically
    keyed to individual proteins, carbohydrates and
    fats. These enzymes do not "cancel each other
    out," because they remain in different areas of
    the digestive tract.
  • Furthermore, if digestion did not occur, the
    resulting lack of protein and carbohydrate
    absorption would most likely result in weight
    loss, not the weight gain Somers' predicts.
    Somers' advice not to drink water with meals
    because it dilutes the digestive juices and slows
    digestion is also without merit from Amer.
    Inst. Of Cancer Research

8
  • The New Beverly Hills Diet, by Judy Mazel and
    Michael Wyatt
  • Ms. Mazel has no health or nutrition credentials.
    Her "New Beverly Hills Diet" is fundamentally
    flawed,. Specifically, two of Ms. Mazel's
    theories about digestion are wrong.
  • The premise of her diet is that enzymes found in
    food "activate" the human body. Each of the three
    food groups proteins, carbohydrates and fats
    contain their own set of enzymes to break down
    food so that the body can properly digest it.
  • Mazel advocates a practice she terms "Cautious
    Combining." "It is when you eat and what foods
    you eat together that matters," she claims.
    Fruits, for example, contain all of the enzymes
    necessary to break themselves down into
    nutrients, and move quickly through the system.
    Proteins and carbohydrates, however, require
    special enzymes that slow down the process.
    Furthermore, enzymes from one food can't "cross
    over" to work on other food groups.
  • These suppositions are incorrect. The enzymes
    necessary for digestion are found within the
    body, not in the foods we eat.
  • Mazel also states that fat is just another
    symptom of indigestion, that when food is not
    properly digested, it "causes fatness." In fact,
    quite the opposite is true if foods are not
    properly digested they cannot be absorbed. If
    they are not absorbed, they cannot be metabolized
    into fat or anything else.
  • On a more practical level, Mazel encourages
    consuming a single food grapes for example
    for an entire day. This is not only nutritionally
    inadequate.
  •   Mazel's plan ends up promoting a wide range of
    fundamentally unhealthy habits. Of equal concern,
    however, are the healthy habits it doesn't
    mention. Mazel, like Atkins, neglects to address
    portion control and serving sizes, concepts
    central to any serious program of long-term
    weight management. Perhaps most puzzling,
    however, is Mazel's silence on the subject of
    exercise. Regular physical activity it crucial
    for losing and maintaining weight, but the
    closest Mazel gets to this topic is her
    admonition to chew food thoroughly.
  •   from Amer. Inst. Of Cancer Research

9
Set-point theory - contd
  • In a study with a small set (12) of identical
    twins forced to eat an extra 1000 kcals a day for
    100 days it was found that some gained only 9
    lbs, whereas others gained 29 lbs
  • (also each twin in a pair gained about the same
    amount!).
  • (From 3500 kcals equivalent to 1 lb. fat one
    would have expected 28.6 lb. gain.)
  • This is only one of several studies which
    indicate that different individuals respond to
    excess calories in different ways.

10
Set-point theory
  • Both rats and humans, if forced to eat more than
    they want, put on weight, but after being allowed
    to eat what they want, lose the excess.
  • If a substantial mass of fat is removed, it is
    followed by excess eating and an increase in the
    remaining fat stores!
  • If an obese mouse (due to the ob gene mutation)
    is surgically joined to a normal mouse the former
    will lose weight, presumably due to transfer of
    the hormone leptin from the normal mouse to the
    blood of the obese one.

11
Contd
  • One well-documented metabolic change on
    weight-loss through dieting is a substantial
    decrease in the resting metabolic rate - this may
    be decreased by as much as 50 - and is thought
    to reflect the body's going into "starvation"
    mode. As a result weight loss drops off
    dramatically since the body is using many fewer
    calories - this is a very strong argument against
    using very low calorie diets (

12
Set-point theory contd
  • Some types of adipose tissue are known as brown
    fat, due to the color. The color is imparted by
    cells which are very rich in mitochondria. Its
    main function seems to be to produce heat.
  • Hibernating animals have large amounts. In
    studies with rats, overfeeding leads to increased
    amounts of brown fat and increased heat
    production.
  • For example rats fed 80 excess kcals over
    controls put on only 27 more weight, but
    increased their energy production by a factor of
    two as measured by oxygen consumption.
  • Obese rats don't adjust.

13
Is this you?
  • Much of our eating and drinking is determined by
    social settings and customs, e. g. the stereotype
    of sitting down to watch TV with a bag of chips
    and a bottle of beer (lots of calories - 5 kcals
    per chip, 150 kcals for the beer (180 for a
    typical slice of pizza)).


14
Obesity, Weight loss and diets
  • The maximum sustainable amount of fat a person
    can lose in a day is about 0.6-0.7 pound. Any
    additional weight lost is water.

15
Health problems associated with obesity
  • hypertension,
  • Type II or non-insulin-dependent,
    (maturity-onset) diabetes,
  • heart disease,
  • hypercholesterolemia,
  • hypertriglyceridemia,
  • cancer,
  • accidents,
  • kidney and gall bladder disease,
  • arthritis
  • and gout.
  • People who are obese are three times more likely
    to have high blood pressure and diabetes

16
Key points
  • Weight loss (decreased fat) occurs when Cals in
    are less than required for BMR physical
    activity etc.
  • Independent of type of diet
  • Consumption of Cals is estimated to have
    increased significantly in past 30 yrs, with no
    significant increase in physical activity.
  • If fad diets worked we wouldnt have a problem.
  • It is possible that some people who become obese
    have mutations in one of the many proteins and
    peptides involved in weight control, and thus
    they do not respond properly.
  • It is also likely that the ready availability of
    excess Cals leads to people gaining weight (as
    the rats do), but after a period of excess weight
    their set-points become re-set so that they no
    longer lose the excess weight when on a lower Cal
    diet.

17
The need for exercise
  • Exercise appears also to be an important
    component. The mechanism by which the body
    controls its weight seems not too function very
    well if the person gets less than some minimum
    threshold of exercise (probably about 1 hr per
    day of exercise (at least 30 min)).
  • There is an exceedingly strong correlation for
    children between the number of hours they watch
    TV and obesity obesity increases by 2 for every
    extra hour watched per day!

18
Estimation of Body Fat
  • Underwater weighing Most accurate
  • Fat is less dense than lean tissue
  • Fat floats
  • Skin calipers
  • Electrical resistance

19
Body Fat Distribution
  • Upper-body (android) obesity
  • Associated with more heart disease, Type II
    Diabetes
  • Fat affects livers ability to clear insulin and
    lipoprotein
  • Encouraged by testosterone and excessive alcohol
    intake
  • Defined as waist measurement of 40 in men and
    35 in women

20
Body Fat Distribution
21
Body Fat Distribution
  • Lower-body (gynecoid) obesity
  • Encouraged by estrogen and progesterone
  • After menopause, upper-body obesity appears
  • Less health risk than upper-body obesity

22
Overweight and Obesity
  • Underweight BMI
  • Healthy weight BMI 18.5-24.9
  • Overweight BMI 25-29.9
  • Obese BMI 30-39.9
  • Severely obese BMI 40

23
Juvenile-Onset Obesity
  • Develops in infancy or childhood
  • Increase in the number of adipose cells
  • Adipose cells have long life span and need to
    store fat
  • Makes it difficult to loose the fat (weight loss)

24
Adult-Onset Obesity
  • Develops in adulthood
  • Fewer (number of) adipose cells
  • These adipose cells are larger (stores excess
    amount of fat)
  • If weight gain continues, the number of adipose
    cells can increase

25
Causes of Obesity
  • Genetic factors
  • Identical twins raised apart have similar weights
  • Genetics account for 40-70 of weight
    differences
  • Genes affect metabolic rate, fuel use, brain
    chemistry, body shape
  • Thrifty metabolism gene allows for more fat
    storage to protect against famine

26
Causes of Obesity
  • Environmental factors
  • Learned eating habits
  • Activity factor (or lack of)
  • Poverty and obesity
  • Female obesity is rooted in childhood obesity
  • Male obesity appears after age 30

27
Why Diets Dont Work
  • Obesity is a chronic disease
  • Treatment requires long-term lifestyle changes
  • Dieters are misdirected
  • More concerned about weight loss than healthy
    lifestyle
  • Unrealistic weight expectations

28
  • Phony weight-loss patch marketers settle FTC
    charges.
  • Marketers of the "Peel Away the Pounds" patch,
    which was widely advertised in infomercials, have
    agreed to settle Federal Trade Commission charges
    that they made false and unsubstantiated weight
    loss claims in violation of the FTC Act.
  • The defendants falsely claimed that the
    seaweed-based skin patch causes as much as three
    to five pounds of weight loss per week, and made
    other false and unsubstantiated claims e. g.
    "Simply follow our system Place Pound A Patch on
    your upper body. Then carry on with your everyday
    lifestyle. Every three days peel off the patch
    and watch as you take off the pounds. Replace
    with a new patch and drop more pounds. It's that
    easy."
  • The settlement requires the defendants to pay 1
    million consumer redress payment. It contains a
    24.4 million judgment, which is suspended except
    for the 1 million payment, with an "avalanche
    clause" that requires the defendants to pay the
    full amount if they understated their financial
    status.

29
Any claims that you can lose weight effortlessly
are false
  • .The only proven way to lose weight is either to
    reduce the number of calories you eat or to
    increase the number of calories you burn off
    through exercise. Most experts recommend a
    combination of both.
  • Very low-calorie diets are not without risk and
    should be pursued only under medical supervision.
    Unsupervised very low-calorie diets can deprive
    you of important nutrients and are potentially
    dangerous.
  • Fad diets rarely have any permanent effect.
    Sudden and radical changes in your eating
    patterns are difficult to sustain over time. In
    addition, so-called "crash" diets often send
    dieters into a cycle of quick weight loss,
    followed by a "rebound" weight gain once normal
    eating resumes, and even more difficulty reducing
    when the next diet is attempted.

30
Contd
  • To lose weight safely and keep it off requires
    long-term changes in daily eating and exercise
    habits. Many experts recommend a goal of losing
    about a pound a week. A modest reduction of 500
    calories per day will achieve this goal, since a
    total reduction of 3,500 calories is required to
    lose a pound of fat. An important way to lower
    your calorie intake is to learn and practice
    healthy eating habits.

31
Beware of the following products that are touted
as weight-loss wonders
  • Diet patches, which are worn on the skin, have
    not been proven to be safe or effective.
  • "Fat blockers" purport to physically absorb fat
    and mechanically interfere with the fat a person
    eats.
  • "Starch blockers" promise to block or impede
    starch digestion. Not only is the claim unproven,
    but users have complained of nausea, vomiting,
    diarrhea, and stomach pains.
  • "Magnet" diet pills allegedly "flush fat out of
    the body."
  • Glucomannan is advertised as the "Weight Loss
    Secret That's Been in the Orient for Over 500
    Years." There is little evidence supporting this
    plant root's effectiveness as a weight-loss
    product.
  • Some bulk producers or fillers, such as
    fiber-based products, may absorb liquid and swell
    in the stomach, thereby reducing hunger. Some
    fillers, such as guar gum, can even prove
    harmful, causing obstructions in the intestines,
    stomach, or esophagus.
  • Spirulina, a species of blue-green algae, has not
    been proven effective for losing weight.

32
Clues to Fraud
  • It is important for consumers to be wary of
    claims that sound too good to be true. When it
    comes to weight-loss schemes, consumers should be
    particularly skeptical of claims containing words
    and phrases like
  • easy
  • effortless
  • guaranteed
  • miraculous
  • magical
  • breakthrough
  • new discovery
  • mysterious
  • exotic
  • secret
  • exclusive
  • ancient

33
High protein diets
  • A high protein diet can cause the body to lose
    calcium, which can lead to development of
    osteoporosis. Osteoporosis can result in broken
    bones.
  • Also ketosis.

34
Low carb diets
  • The arguments of people that favor quick weight
    loss diets is that if you eat enough protein, you
    will spare your own body protein from being
    broken down and instead will break down your
    body's stored fat.
  • It turns out this isnt what happens.

35
Low carb diets
  • It is important to realize that claims for rapid
    weight loss diets are misleading. For example,
    low carbohydrate diets lead to a loss of several
    (5-10) lbs in the first few days however, very
    little of this is fat. The weight lost comes from
    glycogen, protein, and mostly water! Usually at
    most two pounds of fat is lost in the first week.

36
Contd
  • Low carbohydrate diets may also lead to
    significant loss of lean tissue (muscles) as the
    body uses amino acids as a source of glucose for
    the brain. This has led to cases of heart
    failure.
  • Such diets also raise serum levels of uric acid
    (increases chance of gout), alter electrolyte
    balance leading to heart arrhythmias, increase
    risk of kidney damage, and adversely alter some
    blood lipid levels.

37
Liquid protein diets
  • Originated in hospitals.
  • ( "The Last Chance Diet" a book by the promoter
    of one of these products - a typical rip-off).
    The idea was to have a very low intake of
    calories, mostly from protein. This would spare
    the protein tissue in the body from breaking
    down.
  • Over 40 deaths were reported before some of these
    products were banned (probably from mineral
    disturbances).

38
Liquid protein diets
  • Liquid protein formulations usually contain
    ground-up animal hooves, bones, horns, skin etc.,
    dissolved with the aid of proteases
  • often deficient in the essential amino acids and
    vitamins and minerals.
  • Harmful effects arise from kidney and liver
    problems, electrolyte imbalance, and dehydration
    among others.

39
Lifestyle Vs. Weight Loss
  • Prevention of obesity is easier than curing
  • Balance energy in(take) with energy out(put)
  • Focus on improving food habits
  • Focus on increase physical activities

40
What It Takes To Lose a Pound
  • Body fat contains 3500 kcal per pound
  • Fat storage (body fat plus supporting lean
    tissues) contains 2700 kcal per pound
  • Must have an energy deficit of 2700-3500 kcal to
    lose a pound per week

41
Characteristics of a sound weight loss program
  • Nutritional adequacy, Sufficient kcals to
    minimize hunger and fatigue
  • Slow weight loss (1-2 lbs/week)
  • Plan designed to meet individual needs (food
    preferences etc)
  • Plan based on readily obtainable foods, socially
    acceptable
  • Eat smaller portions and choose from a variety of
    foods.
  • Load up on foods naturally high in fiber Fruits,
    vegetables, legumes, and whole grains.
  • Limit portions of foods high in fat dairy
    products like cheese, butter, and whole milk red
    meat cakes and pastries.
  • Focus on changing eating habits
  • Ample physical activity

42
How much to lose?
  • Nutritionally adequate diets have at least 1000
    kcals/day. So if we assume a person takes in 1000
    kcals/day we can calculate how much fat they will
    lose.
  • Suppose that they are really committed and
    exercise as well as dieting (this is hard because
    on the low calorie diet your body "says" it
    doesn't want to do anything which costs energy).
    So we'll assume the person's energy requirement
    is 2200 kcals/day. This means they will have a
    deficit of 1200 kcals/day, which corresponds to
    approx.1/3 lb of adipose fat. So over a week they
    will lose around 2 lbs of fat!

43
Weight cycling - Yo-Yo diets
  • This phenomena is observed in animal studies as
    well as with humans.
  • Several studies suggest that weight gain occurs
    more readily with repeated cycles of weight loss.

44
Why do people who diet rarely succeed in
maintaining a lower weight?
  • In addition to the initial weight loss to bring
    the person's weight to the desirable range, the
    biggest problem is then maintaining it there.
    This must involve changes in the person's eating
    habits and exercise patterns. What usually
    happens is weight cycling (or the yo-yo
    syndrome)
  • Dieting leads to rapid weight loss, decreased
    BMR, fatigue and decrease in physical activity
    and food craving
  • This leads to a return to the former eating
    habits and overeating
  • Which leads to rapid weight gain, guilt and shame
  • Leading to a new desire to lose weight and the
    restart of the cycle

45
Contd
  • This cycling leads to effects on the person's fat
    metabolism for example the rate of loss of
    weight on the same diet the second time round is
    lower.
  • BMR's appear to remain at a lower level.
  • Also body composition changes, during dieting
    both fat and lean tissue are lost, but on regain
    more fat is regained relative to lean tissue.
  • Thus repeated cycles actually make the person
    have a higher percent fat!
  • In addition some studies indicate an increased
    risk of CVD after weight cycling.

46
How some succeed
  • Weight-control behaviors of more than 3,000
    American adults who have lost an average of 60
    pounds and have kept it off for an average of six
    years.
  • How do they do it?
  • These successful losers report four common
    behaviors.
  • They eat a low-fat, high-carbohydrate diet,
  • They monitor themselves by weighing in
    frequently,
  • They are very physically active,
  • They eat breakfast. Eating breakfast every day is
    contrary to the typical pattern for the average
    overweight person who is trying to diet.
  • Six years after their weight loss, most of the
    registrys successful losers still report eating
    a low-calorie, low-fat diet, with about 24
    percent of calories from fat.
  • They also exercise for about an hour or more a
    day, expending about 2,800 calories per week on a
    variety of activities. This is equivalent to
    walking 28 miles a week, or four miles a day.
  • More than 70 percent of the registrys weight
    losers became overweight before age 18.
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