Carbohydrate- & Fat-Modified
Diets for Malabsorption
Chapter 19
Nutrition & Diet Therapy (7th Edition)
I. Malabsorption Syndromes
• Malabsorption disorders- most harmful to nutrition
status and result in:
– Nutrient deficiencies
– Weight loss
– Serious complications
• Disorders associated with malabsorption
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Genetic disorders
Pancreatic disorders
Intestinal disorders
Intestinal infections
Liver disease (bile insufficiency)
Surgeries
• Rarely involves single nutrient
• Treatment of malabsorption disorders (surgery and
medications) may also weaken nutritional status
Nutrition & Diet Therapy (7th Edition)
Nutrition & Diet Therapy (7th Edition)
Malabsorption Syndromes cont’d
• Fat malabsorption
– Causes
• Illness that interferes
with production or
secretion of bile (severe
liver disease) or
pancreatic lipase
(pancreatitis, cystic
fibrosis)
• Damage to intestinal
mucosa (inflammatory
disorders or radiation
treatments)
• Motility disorders causing
rapid gastric emptying or
intestinal transit
Nutrition & Diet Therapy (7th Edition)
– Consequences: losses of food
energy, essential fatty acids,
fat-soluble vitamins, some
minerals
• Weight loss
• Deficiencies of fat-soluble
vitamins
• Formation of soaps by some
minerals & unabsorbed fatty
acids
• Bone loss from calcium
deficiency
• Increased risk of kidney
stones (Ca oxalates)
• Fat malabsorption (con’t)
– Dietary adjustments: fat-restricted diet
• Relief of abdominal symptoms (diarrhea &
flatulence)
• Minimize loss of vitamins & minerals
• Fats should not be restricted more than
necessary
• Alternative source of dietary fat: mediumchain triglycerides (MCT)
Nutrition & Diet Therapy (7th Edition)
MCT
Triglycerides with fatty acids that do
not require digestion; can be absorbed
without lipase or bile
Malabsorption Syndromes cont’d
• Bacterial overgrowth
– Gastric acid & peristalsis protect stomach &
small intestine from bacterial overgrowth
– When overgrowth does occur, disrupts fat
digestion & absorption
– Eventually results in deficiencies of fat-soluble
vitamins
– Bacteria compete with vitamin B12, impairing
its absorption
– Symptoms: chronic diarrhea, abdominal
discomfort, bloating, weakness, weight loss
Nutrition & Diet Therapy (7th Edition)
• Bacterial overgrowth (con’t)
– Causes
• Impaired intestinal motility
– Some types of gastric surgery
– Strictures, obstructions & diverticula in small intestine
• Reduced secretion of gastric acid
– Atrophic gastritis
– Acid-suppressing medications
– Acid-reducing surgery
– Treatment
• Antibiotics
• Surgical correction of anatomical defects
• Dietary supplements-fat soluble vitamins, Ca, vit B12
Nutrition & Diet Therapy (7th Edition)
II. Lactose Intolerance
• High incidence:
approximately 75% of
population worldwide
– Rarely serious
– Most individuals (with
lactose intolerance) can
tolerate milk if consumed
with other foods & limit
amount consumed at one
time
• Cause: reduction or loss of
lactase, enzyme that
digests lactose in milk
products
• Prevalent among certain
ethnic groups: Asians,
African Americans, Native
Americans, Ashkenazi
Jews, Latinos
Nutrition & Diet Therapy (7th Edition)
• Dietary management
– Gradually increased
consumption of lactosecontaining products
– Divide milk intake
throughout the day
– Consume milk with meals
– Chocolate milk may be
better tolerated than plain
– Aged cheeses well tolerated
(little lactose content)
– Yogurts with live bacterial
cultures that aid in lactose
digestion
– Low lactose or acidophilus
milk?
– Addition of lactase
preparation to milk or use of
enzyme tablet before
consumption
III. Disorders of the Pancreas
• Maldigestive and malabsorption problems due to
impaired secretion of digestive enzymes
• Pancreatitis
– Inflammatory disease, resulting in damage to pancreatic
tissue & release of enzymes
– Acute pancreatitis
• Usually caused by gallstones, excessive alcohol use; also
caused by high blood triglycerides, exposure to toxins
• Symptoms: severe abdominal pain, nausea & vomiting,
abdominal distention
• Usually resolves within a week without complications
• MNT: NPO>clear liquids>low fat diet or hydrolyzed TF
Nutrition & Diet Therapy (7th Edition)
• Pancreatitis (con’t)
– Chronic pancreatitis
may cause irreversible
damage & loss of
pancreatic function
– Majority of cases (70%)
of chronic pancreatitis
caused by excessive
alcohol consumption
– Symptoms: severe
abdominal pain; may be
unrelenting & worsens
when eating
Nutrition & Diet Therapy (7th Edition)
– Consequences
• Fat maldigestion
• Maldigestion of protein &
carbohydrate
• Steatorrhea in advanced
cases
• Weight loss & malnutrition
due to food avoidance
• Reduction in insulin &
glucagon secretions,
resulting in diabetes
• Medical nutrition therapy
– Dietary supplements to
correct nutrient
deficiencies
– Avoidance of all alcohol
– Pancreatic enzyme
replacement
Disorders of the Pancreas cont’d
• Cystic fibrosis
– Genetic disorder characterized by abnormally thick
exocrine secretions; often leads to respiratory illness
& pancreatic insufficiency
– Consequences
• Major complications: involve lungs, pancreas, sweat
glands
• Persistent respiratory infections, causing inflammation
of bronchial tissues & progressive airway obstruction
• Accumulation of digestive enzymes in pancreas due to
thick pancreatic secretions that obstruct pancreatic
ducts
• Malabsorption of protein, fat & fat-soluble vitamins
• Excessive loss of salt in sweat, increasing dehydration
• Chronic undernourishment, poor growth, difficulty
maintaining body weight
• Pancreatitis, Hyperglycemia & diabetes
Nutrition & Diet Therapy (7th Edition)
• Cystic fibrosis (con’t)
– Medical nutrition therapy
• Increased energy intake (children may need 120150% of recommended energy intake for normal
growth & nutrition status)
• High-kcalorie & high-fat foods
• Frequent meals & snacks
• Supplement meals with milk shakes or liquid dietary
supplements
• Supplemental tube feedings if energy intake is
inadequate
• Pancreatic enzyme replacement at every meal or
snack
• Multivitamin & fat-soluble vitamin supplements
• Liberal use of table salt & salty foods
Nutrition & Diet Therapy (7th Edition)
IV. Disorders of the Small
Intestine
• Malabsorption common consequence when
intestinal mucosa damaged due to
inflammation or infection
• Celiac disease
– Abnormal immune response to wheat gluten,
causing severe intestinal damage & nutrient
malabsorption
– Also referred to as gluten-sensitive
enteropathy or celiac sprue
– Symptoms: GI disturbances such as diarrhea,
steatorrhea & flatulence; symptoms
exacerbated by milk products
Nutrition & Diet Therapy (7th Edition)
Comparison of Villi
Healthy Intestine-Villi
Nutrition & Diet Therapy (7th Edition)
Celiac Intestine-Villi
• Celiac disease (con’t)
– Consequences
• Immune reaction to gluten causing changes in
intestinal tissue
– Reduction in mucosal surface area & digestive enzymes
– May be restricted to duodenum or involve entire small
intestine
• Malabsorption of all nutrients, especially
macronutrients, fat-soluble vitamins, electrolytes,
calcium, magnesium, zinc, iron, folate, vitamin B12
• Stunted growth in children, severe underweight
• Iron-deficiency anemia
• Low bone mineral density
Nutrition & Diet Therapy (7th Edition)
• Celiac disease
(con’t)
– Medical nutrition
therapy
• Life-long adherence to
gluten-free diet
• Symptom relief usually
evident within weeks,
but mucosal healing
may take years
• Avoidance of lactosecontaining foods if
lactose intolerant
• Dietary supplements
Nutrition & Diet Therapy (7th Edition)
Gluten-free diet
• Elimination of foods
containing wheat, rye,
barley
• Careful review of all
ingredients on food labels
(even small amounts of
gluten can aggravate
symptoms)
• Use of gluten-free products
MNT for Celiac Disease
Nutrition & Diet Therapy (7th Edition)
Nutrition & Diet Therapy (7th Edition)
Disorders of the S.I. cont’d
• Short-bowel syndrome
– Malabsorption syndrome that follows resection
of small intestine, causing insufficient
absorptive capacity in remaining intestine
– Surgical resection of major portion of small
intestine (treatment of Crohn’s disease, small
intestinal cancers, other intestinal disorders)
– Results in fluid & electrolyte imbalances,
multiple nutrient deficiencies
– Symptoms: diarrhea, steatorrhea,
dehydration, weight loss, growth impairment
(in children)
Nutrition & Diet Therapy (7th Edition)
Nutrition & Diet Therapy (7th Edition)
• Short-bowel syndrome (con’t)
– Intestinal adaptation: process of intestinal
recovery, after resection, leading to improved
absorptive capacity
– Ileum has greater adaptive capacity than
jejunum
• Permanent effects on vitamin B12 nutrition & bile acid
reabsorption if ileum removed—worsens fat
malabsorption & diarrhea
• Removal of sphincter between ileum & cecum may
result in infiltration of colonic bacteria into small
intestine, causing bacterial overgrowth
Nutrition & Diet Therapy (7th Edition)
• Short-bowel syndrome (con’t)
– Medical nutrition therapy
• Immediately after surgery: fluid & electrolyte
replacement (intravenous)
• First weeks: rehydration of diarrheal fluid losses
• Total parenteral nutrition, gradually reduced as oral
feeding resumes
• Introduction of oral feedings as soon as possible to
promote intestinal adaptation
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Sips of liquid formulas, progressing to larger amounts
Solid foods, as tolerated
Small, frequent feedings
Low-fat, high-carbohydrate diet, if steatorrhea
Vitamin & mineral supplements
Low-oxalate diet to reduce risk of kidney stone
development
Nutrition & Diet Therapy (7th Edition)
Nutrition in Practice—
Anemia in Illness
• Anemia: condition of having too few red
blood cells
– Frequently first sign of another illness
– May be reason for seeking medical attention
– Develops when red blood cells (erythrocytes)
are not produced in sufficient quantity,
destroyed too quickly, lost due to bleeding
– Red blood cells contain hemoglobin that carries
oxygen to tissues
– Produced in bone marrow (erythropoiesis)
– Causes: Blood loss, malabsorption, chronic
illnesses, medications
Nutrition & Diet Therapy (7th Edition)
Red Blood Cell Production
Nutrition & Diet Therapy (7th Edition)
Nutrient Deficiencies & Anemia
Nutrient
Actions
Result of
Deficiency
Iron
Required for hemoglobin
production
Microcytic anemia:
small, hypochromic
cells
Vitamin B12 &
Folate
Maintains cell membrane
integrity
Macrocytic anemia:
large, immature cells
Vitamin E
Role in hemoglobin
Hemolytic anemia:
RBC breakdown
production
Vitamin B6
Role in hemoglobin
production
Microcytic anemia
Vitamin C
Supports blood vessel
integrity
Fragile, bleeding
capillaries
Protein Energy
Malnutrition
Protein synthesis needed for Anemia
RBC development
Nutrition & Diet Therapy (7th Edition)