chronic gastrointestinal discomfort; and gastric
dumping syndrome, a reaction of the gastrointesti-
nal tract to eating high concentrations of sugar
(sweets) and protein (meats). Excessive body
weight stretches the skin, which may sag and fold
after extensive weight loss. About 30 percent of
people who undergo bariatric surgery subse-
quently have PLASTIC SURGERYoperations such as
panniculectomy and abdominoplasty to remove
excess skin after weight loss.
Outlook and Lifestyle ModificationsMost people require four to eight weeks for full
recovery from bariatric surgery and return to reg-
ular activities. Some people may require longer,
particularly those who experience postoperative
complications. The changes to the gastrointestinal
system that bariatric surgery makes are permanent
and alter the way the digestive process functions,
sometimes in ways that require ongoing medical
care and medications. Many people will also need
to continue taking medications to treat conditions
they had before surgery, such as HYPERTENSIONand
DIABETES.
For several weeks to several months, people
who have gastric bypass procedures to restrict the
size of the stomach must eat liquid or pureed
foods to give their gastrointestinal tracts time to
adjust. The gastric pouch can hold such a limited
volume that it often is necessary to separate eating
and drinking by 30 to 60 minutes. As well, the
person must thoroughly chew food before swal-
lowing, as the gastric pouch lacks the MUSCLE
capacity and size to participate in further breaking
down the size of food particles.
Despite the changes to the gastrointestinal sys-
tem’s structure and function, lifestyle factors such
as food choices and physical exercise remain
important for long-term weight management. The
success of bariatric surgery for maintaining weight
loss depends on the extent to which an individual
makes the necessary changes in these factors. Doc-
tors consider bariatric surgery successful when the
person maintains weight loss of 50 percent of
excess body weight for five years after surgery.
Though many people may lose 100 pounds or
more with bariatric surgery, they may remain
overweight though at a healthier weight than
before surgery.
In general, people who undergo bariatric oper-
ations lose 50 percent of excess body weight in the
first year after surgery. The rate of weight loss
depends on the type of operation and tends to be
most dramatic with gastric bypass operations.
Weight loss tends to peak around three years after
surgery, at 70 to 85 percent of excess body weight.
Five years after surgery, however, about 70 per-
cent of people have regained weight to about 50
percent of the excess (which still falls within the
parameters for successful surgery) and about 5
percent of people have regained all of their lost
weight. Doctors attribute these results largely to
continuation of poor eating habits and physical
inactivity. Food choices and daily exercise are
essential to sustain weight loss over the long term.
Outcome studies of bariatric operations show
evidence that people who maintain their weight
loss lower their risk for CVD and type 2 diabetes
to the same extent as people who lose the weight
through nonsurgical methods. Because weight loss
is so dramatic, some people are able to manage
mild to moderate hypertension and type 2 dia-
betes through lifestyle alone, ending the need for
medications. Researchers believe such findings
further support the role of obesity as an indepen-
dent risk factor for these conditions as well as
demonstrate the health value of WEIGHT LOSS AND
WEIGHT MANAGEMENT.
See also DIET AIDS; DIET AND HEALTH; DIETING; EAT-
ING DISORDERS; LIFESTYLE AND HEALTH; MALABSORPTION;
MINERALS AND HEALTH; MINIMALLY INVASIVE SURGERY;
NUTRITIONAL NEEDS; OBESITY AND HEALTH; SURGERY BEN-
EFIT AND RISK ASSESSMENT; VITAMINS AND HEALTH.body fat percentage The proportion of the
body’s composition that is fat. Body fat percentage
is an indirect indicator of LEAN MUSCLE MASSand
correlates to health circumstances such as FERTILITY
as well as health conditions such as type 2 DIA-
BETESandCARDIOVASCULAR DISEASE(CVD). The body
requires a minimum amount of fat for its func-
tions and activities, generally about 4 percent for
men and 12 percent for women. Body fat percent-
age above 25 percent for men and 32 percent for
women correlates with OBESITY. A high body fat
percentage in combination with ABDOMINAL ADIPOS-
ITY(the “apple” body shape) portends a particu-
larly high risk for CVD, HEART ATTACK, andSTROKE.288 Lifestyle Variables: Smoking and Obesity