Dietary Recommendations After Gastric Bypass
Surgery
by: Protica Nutritional
Research
When obesity gets out of hand,
unresponsive to dietary, lifestyle and medical interventions,
drastic measures are needed to cut down calorie intake.
Morbid obesity with a BMI (body mass index, a measure of
malnutrition) above 40 kg/m2 is an indication for surgical
procedures such as gastric bypass surgery. Gastric bypass is
now a well-trodden path to lower BMI’s and achieve healthier
lives in 18 months or so. First used in the 1950’s, only the
last two decades have seen safe and successful gastric bypass
surgery with any consistency. Half a century of meticulous
observations and patient follow-up
has led to the formulation of strict guidelines to ensure
desired results.
Gastric bypass is a series of steps initiated starting with the
decision to undergo the procedure. Identifying existing
nutritional deficiencies is the first step towards surgery.
Vitamin and mineral deficiency often occur in obesity, and need
to be addressed before the procedure. The surgery itself has
two goals; to reduce the volume of the stomach and shorten the
food transit time in the intestine. After surgery the stomach
cannot receive large meals or participate in digestion. This by
itself limits food intake. Food also bypasses a large part of
the intestine and has little time to interact with liver and
pancreatic enzymes. As a result, nutrition absorbed from diet
drops drastically. In most types of gastric bypass surgeries
done today only 50 cm of the intestine is allowed to function
in normal fashion. Compare this to food absorption taking over
7 feet of small and large intestine before surgery.
With such a radical reduction in the capacity to assimilate
food, the postoperative period can be rather tricky. Only clear
fluids are advised for the first two days while waiting for gut
to recover. The gut is then re-trained for about two months
before it can go back to a normal diet. During the recovery
period the limitations imposed by the gastric bypass procedure
should be kept in mind. After surgery the stomach has become
much smaller and can only hold approximately eight ounces at a
time. The stomach has also lost its ability to pulverize food
to initiate digestion. Consequently the appropriate diet for
postoperative recovery would be a liquid to soft solid diet
that can be taken six to eight times a day in small quantities.
Nutrient fluids are preferable since they can provide hydration
and energy at the same time. Non-nutrient fluids are best
avoided or at least restricted to in-between meals.
The type of nutrient chosen also deserves due consideration.
The chosen macronutrient should not affect the stomach emptying
time while providing enough energy to recover from the surgery.
In this regard carbohydrates and fats are at either end of a
spectrum and neither is suitable. Carbohydrates pass through
very quickly and produce very uncomfortable symptoms like
vomiting, bloating, diarrhea and sweating. Fat slows the gut
considerably, and it is oftentimes ruled out because of its
direct link to obesity. Research suggests that the
macronutrients of choice after gastric bypass surgery are
proteins. Proteins do not change gastric transit time
significantly. A high-protein diet can also provide enough
amino acids for repair and growth after a major surgical
procedure like gastric bypass.
Apart from these advantages, a high-protein diet has a special
role in the treatment of obesity. Gastric bypass restricts
excessive calorie intake to prevent weight gain. However,
accumulated adipose tissue also needs to be expended to achieve
the desired weight loss. The basal metabolic rate (energy
expenditure) should be increased simultaneously to burn stored
fat and reduce BMI. This can be achieved by a high-protein diet
since proteins in diet increase the basal metabolic rate by
stimulating protein synthesis. Observations made during the
postoperative period also confirm this proposition. Unless a
high-protein diet is provided, weight loss often ceases despite
controlled consumption.
Currently, a protein intake of up to 90 grams per day is
recommended in the post-operative period. Given the trauma and
the limitations the gut is subjected to during the procedure,
such a high protein intake can be difficult to maintain. The
gut is hardly ready and often fails to assimilate proteins and
energy from traditional foods and diets. Therefore, a
sugar-free fluid protein concentrate with a high
bioavailability, adequate essential amino acids, vitamins and
minerals is the most appropriate diet in the post-operative
period. Digestion is further facilitated if the protein
concentrate is already pre-digested, or hydrolyzed. Such a
nutrient fluid can simultaneously supply concentrated energy
and hydration even when taken in small quantities.
After recovery and return to a normal diet divided over 3 to 4
meals per day, a high-protein concentrate is still a relevant
supplement between or during meals. The protein supplement
continues to provide thermogenic action necessary to lose
weight essential to sustain weight loss. It also compensates
for any amino acid deficiency in the diet and maintains
nutrition on bad days not uncommon in the months and years
after a major surgery.
REFERENCES
1. Kellum JM, DeMaria EJ, Sugarman HJ. The surgical treatment
of morbid obesity. Curr Prob Surg. 1998;35:791-858.
2. MacLean LD, Rhode BM, Nohr CW. Late outcome of isolated
gastric bypass. Ann of Surg. 2000. 231:524-528.
3. Nutritional Implications of Bariatric Surgery: Perspectives
of Practitioners Audiotape/Handout packages available
post-conference.
4. Weight management—Position of ADA. J Am Diet Assoc.
2002;102:1145-1155
5. Faintuch J, Matsuda M, Cruz ME, et al. Severe
protein-calorie malnutrition after bariatric procedures. Obes
Surg 2004; 14:175–181.
6. Alvarez-Leite J.I. Nutrient deficiencies secondary to
bariatric surgery. Curr Opin Clin Nutr Metab Care
7:569–575.
About The Author
Copyright - Protica Research - www.protica.com
ABOUT PROTICA
Founded in 2001, Protica, Inc. is a nutritional research firm
with offices in Lafayette Hill and Conshohocken, Pennsylvania.
Protica manufactures capsulized foods, including Profect, a
compact, hypoallergenic, ready-to-drink protein beverage
containing zero carbohydrates and zero fat. Information on
Protica is available at www.protica.com
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