Fundamentals of Human Nutrition/Lipid intake
6.4 Lipid Intake[edit | edit source]
Total fat intake for
- Children 2-3 years: 30-35% of calories for date
- Children 4-18 years: 25-35% of calories for date
- Adults: 25-30% of calories for date
Less than 10% of daily calories should be from saturated fatty acids
Maximize the amount of poly - monounsaturated fats compared to other sources of fat.
Minimize the amount of saturated fat intake.
Minimize trans fat as much as possible
Fat intake greater than 35% of calories and increased intake of saturated fat are both associated with height risk of heart disease
Omega-3 Intake: Cardiac societies recommend the intake of 1 g/day of the two omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) for cardiovascular disease prevention, treatment after a myocardial infarction, prevention of sudden death, and secondary prevention of cardiovascular disease (Review Cardiovascular benefits of omega-3 fatty acids Clemens von Schacky, William S. Harri, Cardiovascular Research 73 (2007) 310–315.
In the body, lipids provide energy, insulate against extreme temperatures, protect against shock, and maintain cell membranes however our lipid intake needs to be monitored (Whitney, E., 2007). To monitor our lipid intake one will have to monitor the amount of fats consumed. The amount of fats consumed should be no more than 20-35% of daily calories. There are several different fats like saturated, unsaturated and Trans fats. Saturated fats compared to unsaturated fats should be consumed in the least amount of quantity. Saturated fats are typically found in animal products so food sources like beef, chicken and etc. contain saturated fats. According to the Dietary Guidelines for Americans less than 10% of fat consumed should be saturated. There should be a greater concentration of mono- and polyunsaturated fats in the fat intake. A higher consumption of polyunsaturated can be obtained through food sources like fish, nuts and legumes. It is also important to maintain the recommendation for omega 6 and omega 3 which is 5-10% and 0.6-1.2% respectively. The amount of Trans fat consumed should be very minimal or none existent at all (DGA 2010). The body does use some of saturated fats for metabolic and structural functions but it is not necessary to use saturated fats because these functions can be accomplished by other sources to meet most needs. There has been evidence that indicated that higher intake dietary saturated fats are associated with higher levels of blood total cholesterol and low-density lipoprotein (LDL) cholesterol (DGA 2010). These higher levels in the blood total can increase the risk factors for cardiovascular disease. Therefore it is very important to monitor the fat intake because of the possible health effects.
SanGiovanni conducted a study on elderly participants ranging from 60–80 years old to determine the correlation between lipid intake and severity of age-related macular degeneration (AMD). SanGiovanni noticed that higher intake of polyunsaturated fats and fish was associated with a decrease likelihood of having age-related macular degeneration (SanGiovanni 2007). There are more findings that continue to confirm the better effect of polyunsaturated on in health. Oh observed 787441 women in 1980 who were free of cardiovascular disease and a follow up 20 years later noticed women with increase polyunsaturated fats in their diets compared to saturated fats had a lower risk for cardiovascular disease and Trans fat intake was associated with higher risk for cardiovascular (Oh 2005). Therefore avoiding food sources with partially hydrogenated oils and solid fats will help minimize the amount of Trans and saturated fats in the diet and lower health risks.
6.4.1 Excess[edit | edit source]
Cardiovascular Health: Excessive fat intake is most detrimental to cardiovascular health. Saturated fat is the leading cause of high cholesterol levels in most adults. It is found in a wide variety of foods, many of which are often promoted as healthy, such as milk, cheese and other dairy products. For optimal heart health, limit your intake of saturated fat to less than 10 percent of your overall calorie intake.
Besides the cholesterol implications due to high fat intake, obesity is a factor in the causation of disease. Being overweight or obese is highly associated with increasing the risk of type II diabetes, gallbladder disease, cardiovascular disease, hypertension , and osteoarthritis.
Cancer: An excess of fat and a shortage fiber in your diet can cause cancerous cellular growth, which can spread too many organs. The Office of the Surgeon General reports that overweight conditions resulting from too much fat consumption also increase your risk for developing cancer of the colon, gallbladder, kidney and reproductive organs.
Sadly, obesity is a growing disease in modern American society. Throughout the century, more families across the country take less time to cook at home, and spend more time eating at restaurants where food is more convenient (fast and cheap), but high fat content. Most of the foods served in fast food industry have been fried in oil, which makes its lipid content extremely high. Lack of education about these foods and how harmful too much lipid intake is for your body leads Americans to be the most obese country on the planet. Lack of balance of the macronutrients in the typical American diet leads to the disease we call obesity.
Recent studies show that the balance of lipid intake with other macronutrients can contribute to a healthier body and a way to avoid obesity. One particular study published by the Pennington Biomedical Research Center, showed that there was a significant amount of evidence that lipid intake plays a direct role in the development and treatment of obesity. Based on 28 trials on both animal and human subjects, Bray (1998) concluded that the lipid intake has an effect on obesity.
Obesity is characterized by the accumulation of excess body fat (Bray, 1998). Based on the data obtained from the clinical trials, the it was determined that the slow but constant intake of too much dietary fat (lipids) would lead to an increase in obesity. Fat and carbohydrates are were found to make you equally feeling satiated 15 min after consumption, but 3.5 hours later, fat would still giving you the feeling of satiety, where carbohydrates does not. (Shide, 1995).
In addition, high fat diets causing obesity can be difficult to reverse. In a study done by Faust et al (1978), showed that rats on a high fat diet had a large in crease in adipocytes, regardless if the mice were fed saturated or unsaturated fats. Researchers wanted to see if a change in diet would allow the rats to go back to their normal weight, or below their weight if they were put on a low fat diet. Rolls et al (1980), determined that even if rats ate a high fat diet, they did not return to their original weight, even when fed a low-fat diet. The extra adipose cells still remained in the body, collecting any fat in the rats diet and storing it immediately. That is why obesity in the human population is so hard to reverse because when you are obese you have extra fat cells that store any fat you consume. It takes a long sustained diet of healthy, moderate fat intake to return to a normal level.
A high cholesterol level is detrimental to health and leads to a condition known as atherosclerosis. Atherosclerosis is the build-up of cholesterol on the walls of arteries, which may eventually result in the blocking of blood flow. When this occurs in the arteries of the heart, it is called coronary artery disease.
Deficiency[edit | edit source]
Diseases Associated with a Natural Fat Deficiency:[edit | edit source]
- Immune disorders
- High Blood Pressure
- Heart Disease
- Diabetes: type 2
- Alzheimer’s disease, dementia
- Vision loss
Essential Fatty Acid Deficiency [edit | edit source]
Clinical signs of essential fatty acid deficiency include a dry scaly rash, decreased growth in infants and children, increased susceptibility to infection, and poor wound healing. Omega-3, omega-6, and omega-9 fatty acids compete for the same desaturase enzymes. The desaturase enzymes show preference for the different series of fatty acids in the following order: omega-3 > omega-6 > omega-9. Consequently, synthesis of the omega-9 fatty acid eicosatrienoic acid increases only when dietary intakes of omega-3 and omega-6 fatty acids are very low; therefore, mead acid is one marker of essential fatty acid deficiency. A plasma eicosatrienoic acid:arachidonic acid ratio greater than 0.2 is generally considered indicative of essential fatty acid deficiency . In patients who were given total parenteral nutrition containing fat-free glucose-amino acid mixtures, biochemical signs of essential fatty acid deficiency developed in as little as 7–10 days. In these cases, the continuous glucose infusion resulted in high circulating insulin levels, which inhibited the release of essential fatty acids stored in adipose tissue. When glucose-free amino acid solutions were used, parenteral nutrition up to 14 days did not result in biochemical signs of essential fatty acid deficiency. Essential fatty acid deficiency has also been found to occur in patients with chronic fat malabsorption and in patients with cystic fibrosis. Recently, it has been proposed that essential fatty acid deficiency may play a role in the pathology of protein-energy malnutrition
Omega-3 fatty acids and health[edit | edit source]
Health Benefits of Omega-3 Fatty Acids[edit | edit source]
- In patients with stable coronary artery disease, an independent and inverse association exists between n-3 fatty acid levels and inflammatory biomarkers.
- Omega-3 fatty acids improve macro- and microvascular function in subjects with type 2 diabetes mellitus
- The consumption of omega-3 fatty acid supplements decreases homocysteine levels in diabetic patients.
- Fish oil supplementation improves walking distance in peripheral arterial disease.
- The omega-3 fatty acid docosapentaenoic acid (DPA) reduces the risk of peripheral arterial disease associated with smoking.
- Omega-3 fatty acids appear to be an effective treatment for children with autism.
- Fish oil supplementation has a significant therapeutic effect on children with autism.
- A combination of omega-3 and omega-6 fatty acids as well as magnesium and zinc consumption provide a beneficial effect on attentional, behavioural, and emotional problems of children and adolescents.
- Omega-3 fatty acid supplementation has a therapeutic effect in children with ADHD.
- Omega-3 fatty acids prevent atrial fibrillation after coronary artery bypass surgery.
- Consuming small quantities of fish is associated with a reduction in coronary heart disease.
- Omega-3 fatty acids and vitamin D supplementation results in a substantial reduction in coronary calcium scores and slowed plaque growth.
- Omega-3 fatty acid supplementation reduces total mortality and sudden death in patients who have already had a heart attack.
- Raising blood levels of omega-3 fatty acid levels may be 8 times effective than distributing automated external defibrillators (AEDs), and 2 times more effective than implanting implanting cardioverter defibrillators (ICDs) in preventing sudden death.
- Omega-3 fatty acid reduce the total mortality and sudden death in patients with left ventricular systolic dysfunction.
- Dietary supplementation with omega-3 fatty acids reduces the incidence of sudden cardiac death in patients with myocardial infarction.
- Omega-3 in modest doses reduces cardiac deaths, and in high doses reduces nonfatal cardiovascular events.
- Dietary supplementation with flaxseed oil lowers blood pressure in dyslipidaemic patients.
- Omega 3 fatty acids improve the cardiovascular risk profile of subjects with metabolic syndrome, including markers of inflammation and auto-immunity.
- Fish oil improves tubular dysfunction, lipid profiles and oxidative stress in patients with IgA nephropathy.
- Clinical studies have reported that oral fish oil supplementation has beneficial effects in rheumatoid arthritis and among some asthmatics.
- Omega-3 fatty acid supplementation is associated with reduced mania and depression in juvenile bipolar disorder.
- There is strong evidence that omega-3 fatty acids have a beneficial effect in bipolar disorder.
- Omega-3 fatty acids improve endothelial function in peripheral arterial disease.
- Fish oil has a beneficial effect on blood viscosity in peripheral vascular disease.
- An 8-month treatment with omega-3 fatty acids (EPA and DHA) has a positive effects, such as decreasing inflammation, in patients with cystic fibrosis.
- Omega-3 fatty acids may have a protective effect against mucus over-production caused by pulmonary bacterial colonization in cystic fibrosis.
- Omega-3 fatty acid supplementation reduces inflammatory biomarkers, erythrocyte sedimentation rate, and interleukin-8 concentrations in cystic fibrosis patients.
- DHA increases resistance to Pseudomonas aeruginosa infection.
- EPA and DHA have therapeutic value in the treatment of systemic lupus erythematosus
- EPA supplementation has therapeutic value in the treatment of chronic hepatitis C patients.
- Omega-3 fish oil reduces the severity of symptoms in patients with systemic lupus erythematosus.
- Higher plasma concentrations of EPA and DPA are associated with a lower risk of nonfatal myocardial infarction among women.
- Fish and long-chain omega-3 fatty acid intake reduce the risk of coronary heart disease and total mortality in diabetic women.
- A moderate intake of EPA and DHA may postpone cognitive decline in elderly men.
- The consumption of fish reduces the risk of ischemic stroke in elderly individuals.
- Omega-3 fatty acid consumption is inversely associated with incidence of hypertension.
- Fish oil, but not flaxseed oil, decreases inflammation and prevents pressure overload-induced cardiac dysfunction.
- Omega-3 fatty acids may have a therapeutic effect on postpartum depression.
- Omega-3 fatty acids may have therapeutic value in the treatment of dry eye syndrome.
- Omega-3 fatty acid supplementation exhibits therapeutic value in the treatment of children with attention-deficit/hyperactivity disorder (ADHD) symptomatology.
- Omega-3 Fatty acids supplementation prevents and reverses insulin resistance.
- Omega-3 fatty acids prevent the formation of urinary calcium oxalate stone formation.
- Omega-3 fatty acids are beneficial for children with bronchial asthma.
- Omega 3 fatty acid supplementation may contribute to the prevention of early preterm birth in both low-risk and high-risk pregnancies.
- Omega 3 fatty acids decrease the severity of autoimmune disorders.
- Omega-3 fatty acids resulted in an improvement in weight bearing in dogs with osteoarthritis.
- Omega-3 Fatty Acids has significant therapeutic benefits and drug sparing activity in the treatment of rheumatoid arthritis
- Dietary Omega-3 fatty acids may protect smokers against chronic obstructive pulmonary disease (COPD).
- Omega-3 fatty acids alleviate insulin resistance and fatty liver in obese mice.
- Omega-3 fatty acids were shown to be more effective than placebo for depression in both adults and children in small controlled studies and in an open study of bipolar depression.
- The omega-3 fatty acid EPA is as effective as fluoxetine (Prozac) in treating major depressive disorder.
- Fish consumption reduces the risk of ischemic stroke in men
- Fish consumption is associated with a 63% reduction in prostate cancer-specific mortality.
- Eicosapentaenoic acid (EPA) may have a therapeutic role in attenuating pulmonary hypertension.
- Intake of eicosapentaenoic and docosahexaenoic acids from fish may be associated with a reduced prevalence of allergic rhinitis.
- Cod liver oil (omega-3 Fatty Acids) reduces the need for NSAIDs in patients with rheumatoid arthritis
- Diets containing EPA and DHA have an inhibitory effect on breast cancer growth and metastasis.
- Primary open-angle glaucoma patients have reduced blood levels of DHA and EPA.
- Higher intake of omega 3 fatty acids may reduce the risk of pneumonia.
- A diet low in trans-unsaturated fat and rich in omega-3 fatty acids and olive oil may reduce the risk of age-related macular degeneration.
6.4.2 Excess[edit | edit source]
Not all fats are harmful to a person’s overall health! Humans need fat to survive. As a result, when we do not eat enough fat the body is more susceptible to deficiencies of the fat soluble vitamins A, D, E, and K (Whitney, E., & Rolfes, S. (2016). Understanding nutrition (14th ed.). Australia: Wadsworth, Cengage Learning.). Since these vitamins are fat soluble your body needs fat to put them to use. Diets too low in fat can deprive someone of energy, vitamins, minerals, and essential fatty acids. Deficiencies of the fat soluble vitamins will lead to chronic health consequences that may ultimately become fatal.
The human body is incapable of making only two fatty acids; linoleic acid and linolenic acid. These essential fatty acids need to be obtained from dietary fat intake (Alpha-linolenic acid. (n.d.).). Some foods that provide an abundance of linoleic acid and linolenic acid include fish, nuts, vegetable oils, and seeds (Search Results. (n.d.). Retrieved November 27, 2015). These essential fatty acids can also be obtained in lesser value in solid fatty foods such as pizza, bacon, cheeseburgers, hot dogs, sausages, ribs, and steaks.
Unfortunately, in America much of the essential fatty acids are obtained from solid fats that offer small amounts of the essential fatty acids and abundant saturated fat, trans fat, and cholesterol. Health issues arise when intake of solid fats become excessive. They contribute to chronic heart disease, unhealthy weight gain, and obesity (6 Risks of Eating a Low-Fat Diet. (n.d.).). Unlike protein and carbohydrates that contribute 4 kcalories per gram of energy, fat provides 9 kcalories per gram of energy (Whitney, E., & Rolfes, S. (2016). Understanding nutrition (14th ed.). Australia: Wadsworth, Cengage Learning.).
Because fat provides so much energy it can easily tip person’s energy balance in the positive direction; which is where a person consumes more energy than they expel through physical activity, thermic effect of food, and basal metabolic rate. Moderation and variety of intake of solid fats are key to maintaining enough of essential linoleic acid and linolenic acid.
The dietary reference intakes (DRI) and Dietary Guidelines for Americans say that a 2,000 kcalorie per day diet should include 400 to 700 kcalories from fat; that is about 20 to 35 percent of total kcalories. These recommendations assume that diets with up to 35 percent kcalories from fat can be deemed healthy if intake of saturated fats, trans fats, and cholesterol is low.
If saturated fats, trans fats, and cholesterol are the bad fats, what are the good fats? Monounsaturated and polyunsaturated fats are the healthiest fats! Healthy fat consumption is defined by the consumption of unsaturated fats. These foods provide the most linoleic acids and linolenic acids. More unsaturated food items include olives, mayonnaise, avocados, salad dressing, and peanut butter (Foods High in Linoleic Acid. (n.d.).).
As you can see, it is not as easy to consume 400 to 700 kcalories of nuts, fish, and peanut butter as it is to consume meats, chocolate, and eggs on a daily basis. Saturated fats taste better and are more fulfilling, but hurt your overall health in the long run.
References[edit | edit source]