Bariatrics is the field of medicine that is concerned with the
cause(s), prevention, control, and treatment of obesity and
related to obesity. Obesity is an abnormal increase in the
amount of fat cells in the body compared to the amount of
other types of cells. The term “bariatric” is most frequently
used in reference to bariatric surgery, which is another way
to refer to weight-loss surgery. This involves reducing the
stomach size, removing a part of the stomach, or removing
and re-directing the small intestine to a small stomach
pouch. The latter is referred to as gastric bypass surgery.
The small intestine is the part of the intestine that takes in
all of the nutrients that the body needs.
Bariatric doctor meets with a
patient to discuss treatment.
In addition to weight-loss surgery, bariatrics also involves teaching patients how to lose
weight via diet and exercise, psychological techniques, or use of medications. Bariatric
surgery is typically reserved for patients in whom non-surgical treatments have not
worked. Failed non-surgical obesity treatment is most common in severe obesity, where
surgical treatment is more likely to lead to greater weight loss, better health outcomes,
and improved quality of life.
There are four main types of bariatric surgery treatments: gastric bypass surgery, gastric
sleeve surgery, adjustable gastric band, and biliopancreatic diversion with duodenal
switch (BPD/DS). A review of each method follows:
1. Gastric bypass surgery: Commonly referred to as “gastric bypass” and scientifically referred to as
the Rouex-en-Y (RNY) gastric bypass, this surgical technique involves dividing the stomach into a small
upper area (known as the pouch) and a much bigger lower area (known as the remnant because that is
the area that is left over). The small intestine is re-routed so that the top part connects with the stomach
pouch and the lower part connects with the remnant. Being much smaller than the regular stomach, the
pouch can only hold one or two ounces of food or liquid at a time. The remnant area produces fluid
important for digestion. With the small intestine being split into the shape of a “Y,” food/liquid travels
down one part of the small intestine whereas the remnant area produces enzymes for digestion that
eventually intersects with the food/liquid carried by the other part of the small intestine.
Because there is a smaller area of the stomach designated to hold food, gastric bypass surgery results
in significant weight loss initially (60 to 80% in the first 12 to 18 months). Although 20% of gastric bypass
surgery patients will gain some of the weight back, most people will keep about half of the weight off
after surgery. Due to the significant weight loss, many obesity-related medical problems often resolve
after gastric bypass surgery.
2. Gastric sleeve procedure (also known as sleeve gastrectomy, the sleeve, and laparoscopic sleeve
gastrectomy): This is a procedure in which most of the stomach is removed (about 80%) and a new tube-
shaped stomach area known as a sleeve is created. This procedure is an option for people who do not
qualify to safely undergo other bariatric procedures and is considered to be essentially as effective as
After a gastric sleeve procedure, weight loss typically occurs at a slower but steadier rate than gastric
bypass surgery. The procedure is also known to cause improvements in gut hormones that leads to less
hunger and more of a sense of fullness. Weight loss is typically 60 to 70% in the first 12 to 18 months
after this procedure. Due to the significant weight loss that occurs, many obesity-related medical
problems often resolve after gastric bypass surgery as well.
3. Adjustable gastric band procedure (also known as the band): An inflatable bland is placed around
the top part of the stomach to cause a small stomach pouch on top of the band and a larger area below.
Thus, this procedure results in a smaller stomach pouch by restricting the size of the opening. The size
of the opening can be adjusted with a saltwater solution injected under the skin into a device known as a
port. This technique is used to reduce the stomach opening over time. The band procedure reduces the
amount of food that can enter and leave the pouch area. Unlike the prior two procedures mentioned,
food is digested and absorbed as it usually would because there is no rerouting of the intestines. This is
a shorter, reversible procedure and patients are typically discharged home the same day. Hunger is
known to be reduced after gastric band procedures. Weight loss tends to be about 40 to 50% afterwards.
4. BPD/DS: In this procedure, a small tube-shaped stomach pouch is created and a large area of the
small intestines is re-routed so that about three fourths of the small intestine is bypassed by the food
stream. Favorable changes in gut hormones occur to decrease hunger and increase fullness. Towards
the end of the small intestine, the food mixes with the bile and enzymes from the pancreas. Bile is a
bitter, yellow-green substance released from the liver that carries away waste products. The pancreas is
a long organ behind the stomach that produces several types of hormones and helps digest food with
pancreatic juices that contains enzymes. An enzyme is a type of protein that helps produce chemical
reactions in the body. BPD/DS involves more of a risk for complications than other the other surgical
procedures including protein and vitamin deficiencies. Weight loss tends to be 60 to 70% after the
procedure but allows patients to eat at near normal levels.
Bariatric means pertaining to bariatics. Bariatrics comes from the Greek word "baros" meaning "weight"
and the "iatros" meaning "physician." Put the words together and you get "weight physician."