and Food Sources
The hormone insulin is
essential for the use and storage of nutrients. Insulin promotes nutrient storage and inhibits use of stored energy sources.
promotes the entry of glucose into cells, stimulates glycogen formation in the liver
and in muscle cells, and increases triglyceride formation by adipose tissue and liver. Without insulin,
glucose production by the liver (gluconeogenesis) is accelerated and the breakdown
of liver and muscle glycogen into glucose (glycogenolysis) occurs. This causes
blood glucose levels to increase. The effects of counter regulatory hormones such
as glucagon, growth hormone, cortisol, epinephrine, and norepinepherine block
the effects of insulin.
effects of insulin are increased with the action of counter regulatory hormones.
The introduction of oral anti-diabetes
medications, combination insulin regimens, and the use of self-blood glucose
monitoring have improved the patient's ability to manage their disease and enhanced their quality of life. Self-blood glucose monitoring in particular has improved treatment safety and allowed more dietary flexibility. Compared to earlier recommendations, todays
diabetic diet is higher in carbohydrates and lower in protein. Although many
studies have focused on the role of specific nutrients, foods, or food groups
in disease prevention or health promotion, research suggests that health benefits
rely on food patterns that include a variety of foods. In other words, a healthy
diet contains moderate servings of fruits and vegetables, grains, low-fat dairy
products, fish, poultry, and lean meats. The current nutritional guidelines
of the American Diabetes Association (ADA) are consistent with those of the
American Heart Association, the National Cancer Institute, and U.S. dietary
diets used today are lower in carbohydrates than those used in the past.
Dietary Components of Food
Carbohydrates are the bodys primary energy source. Each
gram of carbohydrate provides 4 calories.
disaccharides, and polysaccharides are types of carbohydrates.
Monosaccharides including glucose, fructose, galactose and disaccharides like sucrose,
and lactose are sugars found in fruits, some vegetables, milk, and sweets.
are starches and fiber found in foods such as cereal, grains, starchy vegetables
such as potatoes, peas, and corn, and legumes (peas, beans, and lentils).
- Starch granules are composed of the glucose polymers amylose and amylopectin. Amylose and amylopectin are hydrolysed to maltose, maltriose and dextrins by the enzyme amylase. Maltose, maltriose and dextrins are hydrolysed to glucose at the brush boarder of the small intestine by the enzyme complex, sucrase-isomaltase. Glucose that
is absorbed after digestion of carbohydrate-containing foods usually increases blood glucose concentration for up to two hours. This response
varies from person to person, depending on the persons gastric emptying
rate, intestinal motility, and factors that affect glucose removal from
the bloodstream, such as insulin availablity and insulin resistance.
- Fiber: Soluble
fiber forms a gel in the gastrointestinal tract and may help slow down the
absorption of glucose and lipids. Fiber is an indigestible polysaccharide formed from the cell walls of plants. Although fiber is a polysaccharide, mammals lack the enzymes necessary to hydrolyse it into an absorbable form. Sources of soluble fiber include legumes,
oats, barley, and some fruits and vegetables. Insoluble fiber increases stool
bulk and decreases stool transit time. Whole wheat, corn, bran, and some
vegetables are good sources of insoluble fiber. Studies have shown that diets
high in dietary fiber can lower blood glucose and low-density
lipoprotein (LDL) cholesterol in patients with diabetes.
- Wannamethee, S.; Whincup, P.; et al. found associations Between Dietary Fiber and Inflammation, Hepatic Function, and Risk of Type 2 Diabetes in Older Men. Total dietary fiber ( ≤20 g/day) was associated with increased risk of diabetes after adjustment for total calorie intake. Dietary fiber was inversely associated with inflammatory markers (C-reactive protein, interleukin-6) and with tissue plasminogen activator and γ-glutamyl transferase.
- Vuksan, V.; Rogovik, A.; et al. found that viscous soluble fibers have demonstrated acute and long-term metabolic improvements in type 2 diabetes, such as reductions in hemoglobin A1c, fasting and post-prandial glycemia, insulinemia, and cardiovascular risk factors
- Kalkwarf H; Bell R; et al. found that DM type1 pregnant women who consumed a total of 20.5 grams per day of fiber required 16%-18% less insulin than did cohorts that consumed 8.1 grams per day of dietary fiber.
in the form of potatoes and cereals are polysaccharides.
- Proteins: Protein
is necessary for tissue growth and maintenance and is a potential secondary
source of energy. Each gram of protein provides 4 calories. Dietary
sources of protein are from animals such as meat, milk and other dairy products,
and vegetable sources such as legumes, grains, nuts, and seeds.
- Fats: Fat in the
form of free fatty acids is an important energy source. Each gram of fat
provides 9 calories. Dietary sources of fat are animal sources such as
meat, egg yolk, dairy fat containing foods, and vegetable sources such as
margarine, oils, nuts, seeds, and some high fat fruits such as coconuts and
avocados. Excess glucose is also converted to fatty acids by liver and adipose tissue. Excess fatty acids are converted to triglycerides for long term storage and use during fasting.
- Vitamins, minerals,
and water: Vitamins and minerals are involved in a number of important
body functions. Vitamins are involved in the processing of other nutrients,
and minerals are needed for many enzyme systems to function normally. Water
is also an essential nutrient and is an important component of body tissue,
accounting for between one half to 3/4 of body weight. Water sources include
water, water containing beverages, and water contained in food.