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Chapter 4 Notes – The Carbohydrates: Sugar, Starch, Glycogen, and Fiber
●Carbohydrates meet your body’s energy needs
-feed your brain and nervous system
-keep your digestive system fit
-within calorie limits, help keep your body lean
-together with fats and protein, digestible carbohydrates add bulk to foods
-indigestible carbohydrates yield little or no energy but provide other benefits
●Complex carbohydrates
-starch and fiber
●simple carbohydrates
-sugars
A Close Look At Carbohydrates
●Carbohydrates contain energy that captured through photosynthesis
-Photosynthesis makes use of chlorophyll to capture energy and sunlight
-in this process, water donates hydrogen and oxygen, and carbon dioxide donates carbon
and oxygen
-water and carbon dioxide combine to form the sugar glucose
●Glucose produced by photosynthesis provides energy for the work of all parts of the plant
-plants do not use all the energy stored in their sugars
-some remains available for use by the animal or human that consumes the plant
-carbohydrates are the first link in the food chain that supports all life on Earth
●Carbohydrate-rich roods come almost exclusively from plants
-milk is the only animal-derived food that contains significant amounts of carbohydrate
●Sugars
-The three single sugars (monosaccharides) are glucose, fructose, and galactose
-fructose is the sweet sugar of fruit
-galactose is a component of milk sugar
-glucose, fructose, and galactose all have the same number and kind of atoms arranged in
different ways
-The three double sugars (disaccharides) are lactose, maltose, and sucrose
-Lactose is milk sugar
-it is made of glucose linked to galactose
-Maltose has two glucose units
-it appears wherever starch is being broken down
-Sucrose is table sugar, which is obtained from sugar beets or sugar cane
-it is made of glucose linked to fructose
●Single sugars are absorbed directly into the blood
●Disaccharides must be split into monosaccharides before they can be absorbed
●All products of digestion are delivered to the liver
-the liver contains enzymes that modify nutrients, making them useful to the body
-the liver quickly converts glucose or galactose to glucose or to smaller pieces that can be used to
make glucose, fat, or other needed molecules
-glucose is the most used monosaccharide in the body
●Most of the energy of fruits and vegetables comes from sugars
-however, eating them is not the same as eating concentrated sweets such as candy or colas
●Starch
-Polysaccharides
-Starch
-Glycogen
-Fiber
●Starch
-Starch is a plant’s storage form of glucose
-for example, corn stores clusters of starch molecules in granules and packs the granules
into its seeds
-this insoluble starch will nourish the seed until the new plant is capable of
photosynthesis
-soluble glucose would be washed away by rain
-Starch is nutritive for people because they can digest starch to glucose and obtain the sun’s
energy stored in its chemical bonds
●Glycogen
-Glycogen is the storage form of glucose in animals
-the glucose chains that make up glycogen are longer and more highly branched than those that
make up starch
-there is little glycogen in meats because it breaks down rapidly when the animal is slaughtered
●Fiber
-Some plant fibers provide support to plant structures
-Fibers also retain water to protect seeds from drying out
-most fibers are polysaccharides
●Human digestive enzymes cannot break the bonds that hold together the sugar units of starch
-thus most fibers pass through the human body without providing energy
●Bacteria within the human large intestine can digest fibers to varying degrees by fermenting
them
-the fibers are broken down to waste products
-mainly small fatlike fragments that the colon absorbs
●Many animals, such as cattle, depend on their digestive system’s bacteria to make the energy of
glucose available from the fiber cellulose
-by eating beef we indirectly obtain some of the sun’s energy that was originally stored in fiber
-even though animal products do not contain fiber
●Soluble fibers dissolve in water
-form gels (are viscous)
-easily digested by bacteria in the human colon
-found in barley, legumes, fruits, oats, vegetables
-are associated with a lower risk of chronic disease
-add a pleasing consistency to foods
-thickening them
●Insoluble fibers do not dissolve in water
-are less easily fermented
-the outer layers of whole grains, the strings of celery, etc. contain insoluble fibers such as
cellulose and hemicellulose
-these fibers retain their structure and texture even after hours of cooking
-they aid the digestive system and ease elimination
●Total fiber is the sum of fibers from:
-Dietary fibers
-fiber that naturally occurs in foods
-Functional fibers
-added fibers that have health benefits
-these fibers may be extracted from plants or manufactured in a laboratory
The Need for Carbohydrates
●Glucose, protein, and fats provide energy to the body
-protein-rich foods are usually expensive
-they provide no advantage when used as fuel for the body
-overuse of proteins has disadvantages
●The DRI committee recommends that 45%-65% of daily calories come from carbohydrates
●Fats are not normally used as fuel by the brain and central nervous system
-Glucose is the primary energy source for nerve cells
●Sugar
-Complex sugar molecules coat almost every cell of the body
-Sugar molecules dangle from many of the body’s fat and protein molecules
-Sugars can alter protein shape and function, affect cell communication, and may play roles in
disease processes
●If I Want to Lose Weight and Stay Healthy, Should I Avoid Carbohydrates?
-Despite intense marketing, the best way to lose fat, and maintain lean tissue and health, is to
practice portion size control, control calorie intake, and have a diet that supplies carbohydrates in
balance with other energy nutrients
●Gram for gram carbohydrates contain fewer calories (4) than do dietary fats (9)
●Converting glucose into fat is metabolically costly
●Recommendations are for complex carbohydrates, not refined sugars
-Complex carbohydrates contribute needed nutrients
-Pure sugars displace nutrient-dense foods from the diet
-Contain no other nutrients and thus are empty-calorie foods
●Overuse of sugars may, in many people, alter blood lipids in ways that increase cardiovascular
risks
-Such people should lose weight on a calorie-controlled diet
-High in whole grains, fruits, and vegetables
●Most people should increase their intake of fiber-rich, whole foods
-such as whole grains, fruits, and vegetables
-refined white flour, sugars, and fats associated with heart disease should be used in moderation
●Why Do Nutrition Experts Recommend Fiber-Rich Foods?
-Fiber-rich foods supply vitamins, minerals, and phytochemicals
-these foods also contain little or no fat
-Viscous fibers such as those found in apples have a significant cholesterol-lowering effect
-Insoluble (nonviscous) fiber such as that found in wheat bran is a stool softener
●Benefits of fiber include:
-Promotion of normal blood cholesterol concentrations
-Modulation of blood glucose concentrations
-Maintenance of healthy bowel functions
-Help in the maintenance of a healthy body weight
●Lower Cholesterol and Heart Disease Risk
-Diets rich in complex carbohydrates may protect against heart disease
-such diets are usually:
-low in saturated fat, trans fat, and cholesterol
-high in fibers, vegetable proteins, and phytochemicals
●Foods rich in viscous fibers lower blood cholesterol by binding with cholesterol-containing bile
and carrying it out with the feces
-Bile is needed for digestion, so the liver responds to its loss by drawing on the body’s cholesterol
to make more
-During bacterial fermentation of fiber, a small fatty acid is produced, absorbed, and travels to the
liver where it may help reduce cholesterol synthesis
●Blood Glucose Control
-Viscous fibers trap nutrients and delay their transit through the digestive tract
-As a result glucose absorption slows and this helps maintain steady levels of blood
glucose and insulin
-large fluctuations in blood glucose and insulin are thought to be associated with
the onset of the most common form of diabetes (type II)
-In people with diabetes, high-fiber foods play a role in modulating blood glucose and insulin
levels
-lowering the likelihood of medical complications
●Maintenance of Digestive Tract Health
-Fiber, along with fluid intake, play a role in maintaining proper colong function
-Fibers such as cellulose enlarge and soften stools
-Speeding their passage through the intestine and making for easier elimination
-These fibers help alleviate or prevent constipation
●Constipation is difficult, incomplete, or infrequent bowel movements
-Associated with discomfort in passing dry, hardened feces
-Large, soft stools ease the task of elimination for the rectal muscles
-Making it less likely that the rectal veins will swell (hemorrhoids)
●Fiber prevents compaction of intestinal contents
-Such compaction could obstruct the appendix and permit bacteria to invade and infect it
(appendicitis)
●Fiber stimulates the GI tract muscles so they retain their strength and resist bulging out into
pouches (diverticula)
-Diverticulitis is the inflammation of diverticula
●High-fiber diets lower the rates of colon cancer relative to low-fiber diets
-In addition to fiber, nutrients and phytochemicals found in fiber-rich foods
-Furthermore, fibers dilute and speed the removal of cancer-causing agents from the colon
-Fiber-rich diets promote bacterial reproduction, binding nitrogen and carrying it out of the body
in feces
●In the colon, bacterial fermentation of soluble fibers produces small fatlike molecules such as
butyrate
-Butyrate provides energy to colon cells
-A colon well supplied with butyrate may resist chemical injury that could lead to cancer
- well-fed colon frequently replaces its own lining
-sloughing off cells before they can initiate the cancer process
●Healthy weight Management
-Foods rich in complex carbohydrates tend to be low in fats and added sugars
-they, therefore, promote weight loss by providing less energy
-fibers also create feelings of fullness and delay hunger because they swell as they absorb
water
-Buying such pure fiber compounds is neither necessary nor advisable
●Recommendations and Intakes
-DRI recommendations for fiber:
-Men age 19-50: 38 g/day
-Men age 51+: 30 g/day
-Women age 19-50: 25 g/day
-Women age 21+: 21 g/day
-The ADA recommends 20 to 35 grams of total fiber per day
-This is about 2X higher than the average intake
●Calculating Fiber Intake
-Servings of:
Fruits and Vegetables X3
Refined Grains X1
Whole Grains X3
Beans, Lentils X6
●Recommendations and Intakes
-A good way to add fiber while lowering fat is to substitute plant sources of proteins for animal
sources of protein
-Also, focus on eating 5-9 servings of fruits and vegetables each day
-Eat a variety of high-fiber foods and drink ample fluids
●Binders in Fiber
-Binder is some fibers act as chelating agents
-such agents bind nutrient minerals and carry them out of the body
-for example, excess fiber may limit the absorption of iron, zinc, and calcium
●Too much bulk in the diet can limit food intake and cause both nutrient and energy deficiencies
-The malnourished, the elderly, and children who consume no animal products are particularly
vulnerable
-Fibers remove water from the body and can cause dehydration
-Add 1 or 2 glasses of water to go along with the fiber added to your diet
●Table 4-3 Terms that Describe Grain Foods
bran – the protective fibrous coating around a grain; the chief fiber donator of a grain
endosperm – the bulk of the edible part of a grain, the starchy part
germ – the nutrient-rich inner part of a grain
husk – the outer, inedible part of a grain
enriched, fortified – refers to the addition of nutrients to a refined food product. As defined by
U.S. law, these terms mean that specific levels of thiamin, riboflavin, niacin, folate, and
iron have been added to refined grains and grain products.
Refined – refers to the process by which the coarse parts of food products are removed. For
example, refining of wheat into flour involves removing three of the four parts of the
kernel – the chaff, the bran, and the germ – leaving only the endosperm, composed
mainly of starch and very little protein
Consumer Corner: Refined, Enriched, and Whole-Grain Breads
●When wheat was ground between two stones, the shaft (husk) was removed and the nutrientrich bran, germ and endosperm were retained
●Modern milling machinery removes the germ and bran
-Leaving a whiter, smoother-textured flour
-that has an increased starch content and lower fiber content
●Turning to white bread has meant a loss of nutrients
-Nutrients formerly received from whole-grain bread
-When this problem was recognized, Congress passed the Enrichment Act, requiring the addition
of iron, niacin, thiamin, riboflavin, and folate to fined grains
●The enrichment of grain products eliminated known deficiency problems
-However, other deficiencies went undetected for many years
-Enriched products still contain less magnesium, zinc, vitamin B6, vitamin E, chromium, and
fiber than whole-grain products
From Carbohydrates to Glucose
●Digestion and Absorption of Carbohydrate
-To obtain glucose from food the digestive system must first break down carbohydrates in the
food into monosaccharides that can be absorbed
Starch
●Starch digestion begins in the mouth
-And enzyme in saliva splits starch into maltose
-This enzyme continues to act on starch while it remains in the stomach’s upper
storage area
●As the food is pushed downward and mixed with the stomach’s acid and other juices, salivary
enzymes are deactivated by the stomach’s acid
-Some digestive enzymes, such as a protein digesting enzyme found in the stomach, work best in
acidic environments
●Starch digestion resumes in the small intestine
-where a starch-splitting enzyme produced by the pancreas acts
●Starch found in refined grains is rapidly broken down to glucose which is then absorbed
●Starch, such as that of cooked beans, digests more slowly and releases glucose later in the
digestive process
●Less digestible (resistant) starch is a type of fiber and may behave as a fiber
-Such starches are found in raw potatoes and inside the unbroken husks of swallowed seeds
-Resistant starch also forms during cooking when food is overheated
-Some resistant starch may be digested slowly if at all
-Most remains intact until the bacteria of the colon break it down
Sugars
●Digestible carbohydrates are ultimately split into monosaccharides before they are absorbed
-Disaccharides and small polysaccharides are split by enzymes attached to the cells lining the
small intestine
●Once in the bloodstream carbohydrates travel to the liver
-Here fructose and galactose are converted to glucose or related products
-the circulatory system transports the glucose and other products to the cells
-liver muscle cells may store glucose as glycogen
-all cells may split glucose for energy
Fiber
-Many fibers are not affected by human digestive enzymes
-Many fibers can be fermented by intestinal bacteria
-A by-product of which can be any of several odorous gases
●When changing to a high-fiber diet, gas production can be minimized by:
-Starting with small servings and gradually increasing serving size
-Chewing thoroughly to break up lumps that can ferment in the intestine
-Trying a variety of fiber-rich foods until you find some that do not cause gas
-Relief from excessive gas may be found by using commercial enzyme preparations
-Persistent painful gas may indicate that lactose intolerance has developed
●Why Do Some People Have Trouble Digesting Milk?
-As they age, about 75%-95% of people lose much of their ability to produce lactose
-this results in lactose intolerance, symptoms of which include:
-Nausea, pain, diarrhea, excessive gas
-Intestinal bacteria ferment the undigested lactose resulting in the production of gas and
intestinal irritants
●Sometimes sensitivity to milk is not due to lactose intolerance but to an allergic reaction to the
protein in milk
-Individuals with milk allergy often cannot tolerate cheese or yogurt
-Finding nondairy calcium sources of calcium, such as calcium-fortified orange juice,
calcium-and vitamin-fortified soy drink, canned sardines, and salmon with the bones,
becomes imperative
The Body’s Use of Glucose
●Glucose is the basic carbohydrate unit that each cell uses for energy
-The body maintains an internal supply for use in case of need
-The body tightly controls its blood glucose concentration
-Carbohydrates also serve structural roles in the body
-such as forming part of the mucus that protects body linings and organs
Splitting Glucose for Energy
●The Point of No Return
-Inside a cell, glucose is broken in half, releaseing some energy
-these halves can be put back together to reform glucose
-These halves can be broken into smaller fragments
-in which case, they cannot be reassembled into glucose
-the small fragments can yield more energy as they are broken down to carbon dioxide
and water
-they can be formed into building blocks of protein or units of body fat
●Below a Healthy Minimum
-Body fat cannot be converted into glucose to adequately feed the brain
-with a severe carbohydrate deficit the body must use protein to make glucose
-diverting protein form critical functions of its own
-therefore, carbohydrates prevent the use of protein for energy
-this is the protein-sparing action of carbohydrate
●Fat fragments usually combine with a compound derived from glucose (or protein) before being
used for energy
-without this compound, fat fragments combine with each other producing acidic ketone bodies
-the accumulation of ketone bodies in the blood (ketosis) can disturb normal acid-base
balance
●Ketosis during pregnancy can cause brain damage to the fetus
-resulting in irreversible mental retardation after birth
●Adults with chronic ketosis may face
-Vitamin and mineral deficiencies, loss of bone minerals, altered blood lipids, increased kidney
stone risk, impaired mood and sense of well-being, and glycogen stores that are too low to meet a
metabolic emergency or support maximal high-intensity muscular work
●A therapeutic ketosis-inducing diet has been used, along with medication, to reduce the
occurrence of seizures in children with severe epilepsy
●The minimum DRI to feed the brain and reduce ketosis is 130 grams a day for an average
person
-3x or 4x this minimum is recommended (45%-65% of total energy) to maintain health and
glycogen stores
Storing Glucose as Glycogen
●As blood glucose rises, the pancreas releases insulin
-Insulin signals the body’s tissues to take up glucose
-two thirds of the body’s total glycogen is stored in and used by muscle
-a small emergency store is found in the brain
-the remainder is stored in the liver which makes it available to the body as blood glucose
●When blood glucose concentration drops and cells need energy, the pancreas produces
glucagons
-Enzymes in the liver break down glycogen releasing it into the blood as glucose
Returning Glucose to the Blood
●Regulation of Blood Glucose
-Two safeguards are involved in this
-Replenishment from liver glycogen stores
-Removal of glucose from the blood with the liver converting the excess into glycogen or
fat and muscle converting it into glycogen
●When blood glucose starts to fall too low
-Glucagon triggers the breakdown of liver glycogen to glucose
-hormones that promote the conversion of protein into glucose are released
-only a little protein can be spared
●Epinephrine also breaks down liver glycogen as part of the body’s defense mechanism in times
of danger
-To a person living long ago, this internal source of quick energy was indispensable to a life filled
with physical peril
-This quick-energy response to stress also works to our advantage today
-To meet emergencies, we are advised to eat and store carbohydrates at regularly timed
meals
●Sugary foods and drinks are not the best choices
●Balanced meals, eaten on a regular schedule, help the body maintain its body glucose
-Meals containing starch, fiber, some protein, and a little fat slow digestion
-So that blood glucose enters the blood gradually in an ongoing steady supply
●The Glycemic Response
-The glycermic index (GI) is a measure of the ability of a food to elevate blood glucose and
insulin levels
-Scores are compared with a standard, usually white bread or glucose
-A food’s score depends on several factors
-For example, ice cream, a high sugar food, ranks lower than baked potatoes, a
high-starch food
●Glycemic load
-Glycemic index multiplied by grams of carbohydrate
●The glycemic index, along with glycemic load, may be important to people with diabetes who
must regulate their blood glucose
-The idea being that the lower the glycemic load, the less glucose builds up in the blood, and the
less insulin is needed to maintain normal blood glucose concentration
●Evidence suggests that a low glycemic load may help control body weight
-The carbohydrates of foods release a steady flow of glucose into the blood and extend feelings of
fullness
●High glycemic load foods seem to promote overeating in some overweight people
-And may lead to an increase in the presence of a marker of cardiovascular disease risk
●The glycemic load may be a better tool for diet planning than the glycemic index
-The glycemic load of carrots is much lower than its glycemic index
●Many factors can affect glycemic index test results
-Time of day, body size and weight, blood volume, metabolic rate
-A food’s glycemic effect may vary from person to person
-And depend on how the food is prepared, its ripeness, and which other foods accompany
it in a meal
Handling Excess Glucose
●Excess glucose is stored as glycogen
-Until the muscle and liver are full to capacilty
-To handle excess glucose, body tissues shift to burning fore glucose for energy instead
of fat
-As a result, more fat is picked up and stored by fatty tissues
●If there is still excess glucose
-The liver converts it into fats which are then stored in fat tissues
-Fat cells may also convert glucose to fat
-Fat cells can store practically unlimited quantities of fats
●The conversion of excess glucose to fat requires many steps and costs a great deal of energy
-When presented with both glucose and fat, the body prefers to store the fat and use the glucose to
meet immediate energy needs
-This maximizes energy storage
Diabetes and Hypoglycemia
●Diabetes mellitus
-A disease characterized by high blood glucose levels and inadequate or ineffective insulin
●Worldwide, the prevalence of diabetes is on the rise
-In the U.S. diabetes is the leading cause of blindness
●Additional complications include:
-Amputations
-Complications in pregnancy
-Heart disease
-Kidney disease
-Premature death
-Increased risk of death from flu or pneumonia
●Half of those with diabetes are unaware of their condition
-And therefore fail to take action to prevent its damage
-Early stages often present few or no warning signs
-Recommendations call for everyone over 45 years old (40 in Canada) and younger people with
risk factors, such as obesity, to be tested regularly
●Table 4-7 Warning Signs of Diabetes
-These signs appear reliably in type 1 diabetes and, often, in the later stages of type 2 diabetes
-Excessive urination and thirst
-Glucose in the urine
-Weight loss with nausea, easy tiring, weakness, or irritability
-Cravings for food, especially for sweets
-Frequent infections of the skin, gums, vagina, or urinary tract
-Vision disturbances; blurred vision
-Pain in the legs, feet, or fingers
-Slow healing of cuts and bruises
-Itching
-Drowsiness
-Abnormally high glucose in the blood
●Type 1 and Type 2 are the most common forms of diabetes
-Both are disorders of blood glucose regulation
What is Diabetes?
●Type 1 Diabetes
-Little or no pancreatic secretion of insulin
-Often diagnosed in childhood
-Less common (up to 20% of cases)
-But is on the rise
-Most common chronic disease among children and young adults
●Type 1 diabetes is the result of a person’s immune system attacking the insulin-making cells of
the pancreas
-An immune system attack on the pancreas may be provoked by
-Genetics, viral infection and other diseases, toxins, allergens, disordered immune system
●Treatment:
-Receipt of an external source of insulin
-Meal planning to balance blood insulin and glucose concentrations
●Future treatment:
-Insulin nasal spray and inhaler
-Transplant insulin-producing cells
-Vaccine to prevent occurrence of the disease
●Insulin is a protein
-If taken orally it will be digested
-Must be given as injection
-Daily shots or an insulin pump
●Type 2 Diabetes
-Pancreas makes sufficient insulin
-Body’s cells resist insulin’s action
-Often diagnosed in adulthood
-Incidence has increased by over 60% since 1991
●Characterized by insulin resistance
-A condition in which insulin is less then effective in moving glucose from the bloodstream into
the cells
-As blood glucose rises, so does blood insulin
-Eventually, the pancreas may become less able to make insulin
-With age, people may require insulin to supplement their own supply
●If drugs are necessary:
-A drug that stimulates the pancreas to secrete sufficient insulin to overwhelm the cell’s
resistance
-Or a drug that improves tissue uptake of glucose
●Type 2 Diabetes and the Genes
-There is a genetic component to Type 2 diabetes susceptibility
-Not everyone with these genetic variations gets the disease
-Genetic factors may increase a person’s risk by about 30%
-Diet and exercise play a major role
●In the majority of cases, prevention is likely to occur when individuals control their lifestyle
-Middle-aged men and women can reduce their risk if they:
-Maintain a healthy body weight
-Consume a diet high in vegetables, fruit, fish, poultry, and whole grains
-Exercise regularly
-Restrict alcohol
-Don’t smoke
●Type 2 Diabetes and Obesity
-Type 2 diabetes tends to occur late in life
-Now, overweight children and adolescents are being diagnosed with the condition
●Compared with normal-weight people with diabetes, obese people require much more insulin to
maintain normal blood glucose
-The more body fat, the more insulin resistant, the higher the blood glucose
●Even moderately overweight people exhibit slightly elevated blood glucose (impaired glucose
tolerance)
●Impaired glucose tolerance
-Blood glucose levels higher than normal
-Not high enough to be diagnosed as diabetes
●Many factors contribute to obesity
-According to obesity-diabetes cycle hypothesis, once obesity sets in, metabolic changes trigger
the tissues to resist insulin
-As insulin resistance develops, glucose builds up in the blood, while tissues are deprived
of glucose
-Blood lipid levels rise to meet tissues’ energy demands
-Resulting in circulating fuels available to be stored as fat
●Obesity-diabetes circle hypothesis
-As fat is stored, fat mass increases, insulin resistance worsens, and obesity is perpetuated
●Even moderate weight gain in adults ahs been observed to predict diabetes
●Diagnosis and Perils of Diabetes
-Diabetes can be diagnosed when two or more fasting blood glucose tests register positive
●The tighter the control over blood glucose the less severe the symptoms, such as:
-Blockage or destruction of capillaries, impaired circulation leading to disease of the feet and legs
(often leading to amputation), kidney disease (requiring dialysis or kidney transplant), cataracts,
damaged retinas, nerve damage, skin damage, gum disease, strokes and heart attacks
●Some of this damage may be the result of the oxidation that accompanies elevated blood
glucose
-A diet high in antioxidant-containing vegetables and fruits may be protective
-More research is needed to confirm the oxidation hypothesis
●A person with diabetes should control their weight and all possible lifestyle risk factors that may
contribute to cardiovascular disease
-Aggressive medical treatment of risk factors that arise or heart attacks and strokes may reduce
the occurrence of these killers by as much as 50%
●Nutrition plays a major role in managing diabetes, with a focus in type 2 diabetes on weight
control
-In overweight people with diabetes, weight loss alone helps control the disease
-The same diet that best controls diabetes also helps control body weight and support physical
activity
●Managing Diabetes
-This diet:
-Is adequate in nutrients
-Provides the recommended amount of fiber
-Is moderate in added sugars
-Provides a controlled amount of total carbohydrates
-Is low in saturated fat and may provide some monounsaturated fat
-Is adequate but not too high in protein
●The aforementioned diet is important to the prevention of chronic diseases
-This diet also meets most of the recommendations of U.S. and Canada
●Regular physical exercise plays a major role in preventing and controlling diabetes
-Exercise helps to achieve and maintain a healthy body weight and heightens tissue sensitivity to
insulin
-Even with modest weight loss, increasing physical activity in overweight people seems to delay
diabetes onset
-In those with the disease, increased activity, even without weight loss, often helps to control it
If I Feel Dizzy between Meals, Do I Have Hypoglycemia?
●Hypoglycemia
-Blood glucose concentrations below normal
-May indicate any of several diseases, including impending diabetes
●Postprandial hypoglycemia
-Unusual drop in blood glucose following a meal
-Is accompanied by symptoms of the stress response
-A.K.A. reactive hypoglycemia
●Symptoms include fatigue, weakness, dizziness, irritability, rapid heartbeat, anxiety, sweaty,
trembling, hunger, headaches, confusion, and impairment of intellectual tasks
-These symptoms are so general and common that people can easily diagnose themselves as
having the condition
●This condition is rare except among very lean people or those who have recently lose a great
deal of weight
-Often due to an exaggerated sensitivity to insulin
●Diagnosis requires a test to detect low blood glucose while the symptoms are present
●Fasting hypoglycemia
-Hypoglycemia that occurs after 8 to 14 hours of fasting
-Symptoms are headache, mental dullness, fatigue, confusion, amnesia, seizures and
unconsiousness
-Can be caused by cancer, pancreatic damage, uncontrolled diabetes, liver infection with
accompanying damage, and advanced alcohol-induced liver disease
●It requires extreme measures to induce even mild hypoglycemia with symptoms in normal
healthy people
-Administering drugs that overwhelm insulin and glucagons
●Symptoms that people ascribe to hypoglycemia rarely correlate with low blood glucose
-Such conditions may be classified as nonhypoglycemia
●People with hypoglycemic symptoms may benefit from eating regularly timed, balanced,
protein-containing meals
●They should avoid oscillating between low-carbohydrate dieting and sudden, large refined
carbohydrate doses
●Minimize alcoholic beverages because a high alcohol intake can injure an otherwise healthy
pancreas
Controversy: Sugar And Alternative Sweeteners: Are They Bad For You?
●The preference for sweets diminishes with adulthood
-In the U.S. consumption of sugar and sweeteners is increasing
-The average American consumes almost three-quarters of a cup of added sugar per day
-Over 100 pounds of added sugar per year
Sugar and Alternative Sweeteners
●The upward trend of added sugar consumption parallels an increase in the purchase of
commercially foods and beverages that contain added sugars
-Consumption of soft drinks and sugar-sweetened fruit juices may account for 80% of this
increase
-At home, people are adding less sugar
●People are also consuming more artificial sweeteners
-These substances are intended to reduce sugar intake
-Instead, people are choosing to consume both more sugar and more artificial sugars
●The DRI suggests a maximal intake of 25% of calories or less from added sugars
●The WHO recommends the consumption of no more than 10% of calories from added sugar
●The USDA Food Guide includes added sugars as part of the discretionary calorie allowance
Evidence Concerning Sugar
●Sugar has been accused of:
-Promoting and maintaining obesity
-Causing and aggravating diabetes
-Increasing the risk of heart disease
-Disruption behavior in children and adults
-Causing dental decay and gum disease
●Does Sugar Cause Obesity?
-Over the past decade, obesity rates have risen sharply in the U.S.
-During the same period, sugar consumption has reached an all time high
●When eaten in excess, calories from sugar contribute to body fat stores
●It is unlikely that moderate amounts of sugar would cause obesity when total calorie intakes are
controlled
●People with diets high in sugar often consume more calories per day then people with lower
sugar intakes
-Adolescents who drink about 2 cans of sugar sweetened soft drinks per day consume 400 more
calories a day then teens who abstain from such drinks
-Soft drinks are of particular interest because the increased intake of added sugars is
primarily due to a dramatic rise in high-fructose corn syrup intake
●The trend toward towards greater use of high-fructose corn syrup parallels unprecendented gains
in body fatness in the population
-Overweight children and adolescents increase their risk of becoming obese by 60% with each
additional syrup-sweetened drink they consume per day
-It may be that consumption of sugar in liquid form may go unnoticed by the body; the
body does not reduce energy intake later in the day
●As people gain weight, their physical activity levels decline
-Making it impossible to tell whether the sugar, excess calories from other sources, or too little
physical activity is at fault
●Does sugar cause Type 2 Diabetes?
-Body fatness is more closely related to diabetes than diet is
-High rates of diabetes have not been reported in any society where obesity is rare
-Wherever starch and fiber are the major carbohydrates in the diet, diabetes is rare
-This does not prove that sugar causes diabetes or that starch prevents it
●Evidence to support sugar as a cause of diabetes comes from a six-year large sample size study
-It was found that women who most often chose foods with a high glycemic load develop
diabetes more often than those who most often ate a diet with a low glycemic load
●Conclusion:
-Sugar alone is not the cause of type 2 diabetes
-Sugar may contribute to obesity
-obesity often produces diabetes
-both obesity and diabetes increase heart disease risk
●Saturated fat is the major dietary culprit in heart disease
-Some people seem genetically prone to increased saturated fat production in response to dietary
sugar
-This is especially true of obese people who secrete abnormal amounts of insulin
-Insulin increases liver’s synthesis of saturated fat and stores less in fat tissue
●What about sugar and behavior?
-Children do not react behaviorally to sugar
-Sugar may influence behavior:
-Altering levels of chemicals in the brain
-Inducing nutrient deficiencies
-Stimulating the release of hormones the body secretes after consuming sugar
-Providing pure energy (the Halloween effect)
●Personal Strategy for Using Sugar
-WHO recommendations mean that a person who eats 2000 calories per day is allowed 200 of
those calories from sugar
-This amounts to about 13 teaspoons of sugar
-When you account for the sugars added to foods, 200 calories may seem restrictive
●Suggestion:
-Replace sugar by choosing energy-yielding sugar alcohols (nutritive sweeteners)
-Use the virtually no energy artificial sweeteners (nonnutritive sweeteners)
●Evidence concerning Sugar Alcohols
-Sugar alcohols do not contain ethanol or any other intoxicant
Sugar Alcohols
●Sugar alcohols produce a low glycemic response
-The body absorbs them slowly and thus they enter the blood slower than other sugars
●Side effects such as gas, abdominal discomfort and diarrhea arise from ingesting large quantities
-For this reason, a food that is likely to contribute more than 50 grams of sugar alcohols in a day
must have a label that states, “Excess consumption may have a laxative effect”
●The main benefit of using sugar alcohols is that they do not contribute to dental caries
Artificial Sweeteners
●Evidence Concerning Artificial Sweeteners
-Artificial sweeteners make foods taste sweet and do not promote tooth decay
-they are practically calorie free
●Like all other substances, artificial sweeteners can be toxic if consumed in high enough doses
-The FDA has proposed setting acceptable daily intake (ADI) levels for some artificial
sweeteners
●Saccharin
-Used primarily in prepared foods; also used as a tabletop sweetener
-Slightly elevated risk of some cancers in:
-women who drink 2+ saccharin-sweetened sodas a day
-men and women who smoke heavily and use artificial sweeteners
-other studies have shown no increased risk of bladder cancer
-Large saccharin doses are probably not safe
-Moderate saccharin use in unlikely to cause bladder cancer in humans
●Aspartame
-Used to sweeten foods not exposed to cooking temperatures
-4 calories per gram
-in powder form, it is mixed with lactose
-Flavor is almost identical to sugar
-Touted as safe for children
-Composed of phenylalanine and aspartic acid
-In GI tract, the fragments are split, absorbed, and metabolized just as would be any
protein fragment
-200x sweeter than sucrose
-Poses problems for people with PKU
-A hereditary inability to dispose of excess phenylalanine
-Phenylalanine build-up can cause irreversible, progressive damage if left untreated in
early life
-Newborns are tested for PKU
-If positive for PKU, dietary intake of phenylalanine is limited
-Aspartame is not a recommended source of phenylalanine for children with PKU
-This amino acids occurs in protein and nutrient-rich foods such as milk and meat
-PKU children are allowed only limited amounts of these foods
-Such children have difficulty obtaining many essential nutrients
-Products with aspartame can carry warning labels for people with PKU
-Metabolic by-products include methanol, formaldehyde, and diketopiperazine
-These compounds are not toxic at the levels generated from the ADI of aspartame
-There is no link between aspartame brain cancer, nerve disorders, etc.
-The FDA has set the ADI for aspartame at 50 mg/kg body weight / day
-Canada, has set the ADI at 40 mg/kg body weight / day
-Children under 2 years of age should not be fed artificially sweetened foods and drinks
●Acesulfame-K
-After 15 years of testing and use, there have been no reported health problems
-ADI is 15 mg/kg/bodyweight/day
-About as sweet as aspartame; 200x as sweet as sucrose
-To some, it has a slight aftertaste; which is solved by blending it with other sweeteners
-Used in chewing gum, beverages, instant coffee, tea, gelatins, puddings, table use
-Holds up well during cooking
-Excreted unchanged by the kidneys
●Sucralose
-Only artificial sweetener made from sucrose
-Three Cl substitute for three H and O groups on sucrose
-600x sweeter than sucrose
-Safe to use
-Passes through the body unchanged
-ADI 5mg/kg/bodyweight/day for all ages
-Including pregnant and lactating women
-Heat stable
-Useful in cooking, baking, and as a tabletop sweetener
●Neotame
-Safe for use
-about 7,000-13,000x sweeter than sugar
-Available to food manufacturers but consumers for home use
-Contains phenylalanine and aspartic acid
-Unlike aspartame, neotame is indigestible
-Thus, provides no risk to those with PKU
●Tagatose
-Given FDA status as “generally recognized as safe”
-Used in foods, beverages, confections, dietary supplements, etc
-Derived from lactose, but 80% remains unabsorbed until it reaches the large intestine
-Bacteria in the colon ferment tagatose
-Releasing gas and small products that are absorbed
-At high doses, causes flatulence, grumbling and loose stools
●Other sweeteners
-Cyclamate, once banned, is awaiting FDA approval
-In Canada, is restricted to use as a tabletop sweetener on advice of a physician and as a
sweetening additive in medicine
-Alitame, resembles aspartame
-Awaiting FDA approval
-Composed of two amino acids
-Heat stable
-Stevia, a naturally sweet herb
-used as a sugar substitute, especially in beverages
-Lacks FDA approval because little is known about its health effects
-absorbed by the human GI tract
-Sold as a dietary supplement
●Do Artificial Sweeteners Help with Weight Control?
-Some studies of rats report that intense sweeteners stimulate appetite and lead to weight gain
-Studies on people report that intense sweeteners cause no change or a decline in hunger
●Energy intake has been reported to be lower when artificial sweeteners replace sugar
-Resulting in greater weight losses when obese people use artificially sweetened products
●Personal Strategies for Using Artificial Sweeteners
-Moderate intakes pose no health risks
-Moderation is the key
-Use does not automatically lower energy intake
-Probably do not hinder weight-loss efforts
-Safer for the teeth