Understanding Nutrition, 8e

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Understanding Nutrition, 8e

• Chapter 9 - Weight Control Overweight and
  Underweight

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Overweight Adults in the United States
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Fat Cell Development
Fat cells are capable of increasing their size by
20-fold and their number by several thousandfold.
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Leptins Action in the Body
Leptin maintains energy homeostasis. When the
body gains fat, the increase in leptin shifts
energy balance toward the negative eat less and
spend more energy. Such a scenario would ensure
that all fat gains were followed by losses, but
this is not the case in reality, of course.
Most obese people have high levels of leptin,
but their energy balance does not automatically
shift to the negative, suggesting a resistance to
leptins action in obesity. Figure 9-3b on page
258 shows what happens when leptin balance
declines.
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Leptins Action in the Body
When the body loses fat, the decrease in leptin
shifts energy balance toward the positive eat
more and spend less energy. Most obese people
have high levels of leptin, but their energy
balance does not automatically shift to the
negative, suggesting a resistance to leptins
action in obesity. Figure 9-3b on page 258 shows
what happens when leptin balance decline.
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Mice with and Without Leptin Compared
Both of these mice have a defective ob gene.
Consequently, they do not produce leptin. They
both became obese, but the one on the right
received daily injections of leptin, which
suppressed food intake and increased energy
expenditure, resulting in weight loss. Most
obese people have high levels of leptin, but
their energy balance does not automatically shift
to the negative, suggesting a resistance to
leptins action in obesity. Figure 9-3b on page
258 shows what happens when leptin balance
decline.
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The Weight Cycling Effect of Repeated Dieting
Each round of dieting is followed by a rebound of
weight to a higher level than befor Most obese
people have high levels of leptin, but their
energy balance does not automatically shift to
the negative, suggesting a resistance to leptins
action in obesity. Figure 9-3b on page 258 shows
what happens when leptin balance decline.
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The Psychology of Weight Cycling
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Diet Aids
Most obese people have high levels of leptin, but
their energy balance does not automatically shift
to the negative, suggesting a resistance to
leptins action in obesity. Figure 9-3b on page
258 shows what happens when leptin balance
decline.
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Surgical Procedures Used in Treatment of Obesity
The dark pink areas highlight the flow of food
through the GI tract. Notice that the first
procedure maintains a relatively normal flow
whereas the second one bypasses most of the
stomach, all of the duodenum, and some of the
jejunum. The pale pink areas indicate the
sections that have been bypassed. (a) In vertical
banded gastroplasty, the surgeon constructs a
small gastric pouch and restricts the outlet from
the stomach to the intestine.
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Surgical Procedures Used in Treatment of Obesity
The dark pink areas highlight the flow of food
through the GI tract. Notice that the first
procedure maintains a relatively normal flow
whereas the second one bypasses most of the
stomach, all of the duodenum, and some of the
jejunum. The pale pink areas indicate the
sections that have been bypassed. (b) In gastric
bypass, the surgeon constructs a small gastric
pouch and creates an outlet directly to the
jejunum.
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Weight Goals and Expectations Compared
Reasonable weight goals and expectations
compared. Most obese people have high levels of
leptin, but their energy balance does not
automatically shift to the negative, suggesting a
resistance to leptins action in obesity. Figure
9-3b on page 258 shows what happens when leptin
balance decline.
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The Female Athlete Triad
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Eating Disorders
Exit
The vicious cycle of restrictive dieting and
binge eating.