Nutrition Flashcards
What are the healthiest sources of Carbohydrates?
Unprocessed or minimally processed whole grains, vegetables, fruits, and beans
What are unhealthy sources of carbs?
White bread
Pastries
Sodas
Highly processed or refined foods
What do unhealthy sources of carbs contain?
Easily digested carbs that may contributed to weight gain, interfere with weight loss, and promote diabetes and heart disease
What are simple carbohydrates?
Simple sugars like monosaccharides and disaccharides
What are monosaccharides?
Glucose
Fructose
Galactose
What are Disaccharides?
Sucrose = Glucose + fructose Lactose = Glucose + Galactose Maltose = Glucose + glucose
What are complex carbohydrates?
Starches
Amylose
Amylopectin
What does amylose contain?
Average chain length of 600 glucose residues
What does amylopection contain?
Contains about 6000 glucose residues
What is the glycemic index (GI)?
An in vivo measure of the relative impact of carbohydrate-containing foods on blood glucose
How is the glycemic index determined?
The rapidity of digestion and absorption of its dietary carbohydrates
Quality of the carbs
What is a low glycemix index?
< 55
What is a moderate glycemic index?
56-69
What is a high glycemic index?
> 70
What are the concerns of glycemic index?
Usefulness of the GI for mixed meals
Lack of long-term studies
What foods have a low GI?
Fruits
Veggies
Beans
Minimally processed grains, pasta, low fat dairy foods, and nuts
What foods have a moderate GI?
White and sweet potatoes Corn White rice Couscous Breakfast cereals
What foods have a high GI?
White bread Rice cakes Most crackers Bagels Cakes Doughnuts Croissants
What is the difference between high GI foods and low GI foods?
High GI foods raise the blood glucose levels high and fast
What is the glycemic load (GL)?
Incorporates both quantity and quality of carbohydrate consumption
What is the clinical utility of GL?
Carb rich foods with low fiber content have high GI and GL values
Carbs with high fiber content have low GI and GL values
What are examples of foods that have low fiber?
Potatoes
Refined cereal products
Sugar sweetened beverages
What are examples of foods that are high in fiber?
Whole grains
Fruits
Vegetables
What is a low GL?
< 10
What is a moderate GL?
11-19
What is a high GL?
> 20
How does a patient achieve a lower dietary GL?
Replace carbs with protein
Replace carbs with fat
Replace a high-GI carb with a low GI carb
Combine all of these methods
What is the problem with High Glycemic-index foods?
They cause a transient hypoglycemic state causing:
Increased appetite
Glucagon is released
Increased blood glucose levels
Increased triglycerides
What is the issue with chronic transient hypoglycemic states?
Causes injury to pancreas and insulin resistance occurs
What are the pathogenetic effects of high-glycemic load diets on coronary heart disease?
1) Hypercoagulability
2) Hypercholesterolaemia
3) State of hyperglycaemia and associated hyperinsulinemia causing insulin resistance
4) An insulin resistate state may be pro-inflammatory
5) Hypertension
What causes the hypercoagulability seen in high GL diets?
increase in serum levels of platelet factors like fibrinogen and von Willebrand factor
What causes hypercholesterolemia seen in high GL diets?
Accumulation of visceral fat, reduced lipoprotein lipase activity and reduced clearance of triglycerides
What causes the pro-inflammatory state seen in high GL diets?
Expression of inflammatory mediator TNF-alpha by adipose tissue associated with plasma insulin
What causes the hypertension state seen in high GL diets?
Oxidative stress causes reduced NO which increases vascular and sympathetic tone
Angiotensin by adipose tissue causes activation of the renin-angiotensin system
How do you spot added sugar on food labels?
Line for sugars on the nutrition facts panel contains both natural and added types as total grams of sugar
Added sugars go by many different names so pay attention
Read label = ingredients are listed in descending oder by weight
What does the body not pay attention to?
Doesn’t distinguish between natural or added sugar
What are the daily added sugar limits for men?
9 teaspoons
36 grams
150 calories
What are the daily added sugar limits for women?
6 teaspoons
25 grams
100 calories
What is fructose?
Monosaccharide naturally found in fruits and honey
What is high fructose corn syrup?
Composed of either 42% or 55% fructose and is similar in composition to table sugar (sucrose)
What is excessive consumption of fructose causing?
Insulin resistance Obesity Hypertension Dyslipidemia Type 2 Diabetes
What is dietary fiber?
plant materials that resist digestion
What are examples of soluble fiber foods?
Pectin Guar gum Oat bran Oatmeal Nuts Beans Lentils Apples Blueberries
What are examples of insoluble fiber foods?
cellulose Lignin Wheat Whole wheat bread Whole grain couscous Brown rice Legumes Carrots Cucumbers Tomatoes
What is soluble fiber?
Helps lower glucose levels and blood cholesterol
What is insoluble fiber?
Helps food move through your digestive system, promoting regularity and preventing constipation
What are the best sources of fiber?
Whole grain foods
Fresh fruits and veggies
Legumes
Nuts
What are the building blocks of fats?
Glycerol and fatty acids
What are solid fats?
Lard
Butter
Usually saturated
What are liquid fats?
Veggie oil
Unsaturated
What are Essential fatty acids?
Cannot be synthesized by the body and must be included in the diet
Omega 3 and 6
What are saturated fats?
Best consumed in moderation; solid at room temp.
Red meat
Butter
Cheese
Ice Cream
What are bad, trans fats?
Increase disease risk even when eaten in small quantities
What are good, unsaturated fats?
Monounsaturated or Polyunsaturated; liquid at room temp.
Veggie oils such as olive, canola, sunflower, soy and corn
Nuts
Seeds
Fish
What are the classes of essential fatty acids?
Omega 3 and 6
What is the recommendation for essential fatty acids and why?
Due to low efficiency of conversion of ALA to EPA and DHA, its recommended to obtain EPA and DHA from food sources
What are the functions of essential fatty acids?
1) Membrane structure and function = affect cell membrane fluidity, flexibilty, permeability, and activity of membrane bound enzymes
2) Vision = DHA plays role in regeneration of teh visual pigment rhodopsin
3) Nervous system = Phosphlipids of the brains gray matter contain high proportions of DHA and AA; depletion in brain can cause learning deficits
What is omega 3?
ALA and produces EPA and DHA
Take this as supplement
What is omega 6?
LA and it produces arachadonic acid
What is dietary EPA and DHA?
precursors for anti-inflammatory eicosanoids and inhibit tumor growth
What is arachidonic acid?
Precursor for mainly pro-inflammatory compounds that enhance tumor growth
What was Omega 3 polyunsaturated fatty acid intake associated with?
Lower risk of death due to neurodegenerative disease
What was intake of marine based omega 3 polyunsaturated fatty acids associated with?
Lower respiratory disease mortality and sudden cardiac death
What was the intake of omega 6 polyunsaturated fatty acids associated with?
Lower risk of total death and death due to cardiovascular disease, cancer, and respiratory disease
How is obesity linked to cancer?
Obesity is associated with hyperinsulinemia and to an increase in LDL and a decrease in HDL
Hyperinsulinemia leads to an increase in the free form of IGF-1
IGF-1 is a mitogenic and an antiapoptotic molecule that increases proliferation rates and ultimately causes neoplasm transformation and cancer
What are the three main pathways that mediate trans fatty acid intake with CVD?
1) Serum lipid concentrations increase blood concentrations of LDL, triglycerides, and lipoprotein while also decreasing levels of LDL
2) Systemic inflammation causes a decrease in anti-inflammatory prostaglandins and impairs essential fatty acid metabolism
3) Endothelial cell function causes reduction in NO production
What is the problem with proteins?
Dietary protein has no nutritional value unless it can be hydrolyzed by proteases and peptidases into amino acids, dipeptides, or tripeptides in the small intestine
What is important about amino acids?
They provide nitrogen, hydrocarbon skeletons, and sulfur and cannot be replaced by any other nutrient
They are essential precursors for the synthesis of proteins, peptides, and other substances
Essential for the health, growth, development, reproduction, lactation, and survival of organisms
What is the quality of animal protein products?
Generally they provide more biologically available minerals than plant products
What is practical way to ensure a balanced dietary intake of amino acids?
Eat an appropriate mixture of animal and plant based protein products
What do animal and plant protein products provide?
Source of essential vitamins
Animal = Vit. b12
Plant = folate
What does an adequate intake of protein from calcium and phosphorous rich milk products essential for?
Supports bone growth in infants and children
Maintains health and mass of skeleton in adults
What are lean proteins?
Sole Flounder Cod Halibut Mahi-Mahi Red snapper Orange ruffy Ahi tuna Swordfish Tilapia Grouper Corvina Cobia White eggs Chicken breast Turkey breast London broil Top round Turkey Lamb Pork chops Game Bison Tofu Tempeh Shellfish Scallops
What is the bodies metabolism?
All the chemical reactions in the cells
What is the metabolic rate?
Expressed in terms of heat release during chemical reactions
What is a calorie?
A unit for expressing the quantity of energy released from the different foods
What is 1 calorie?
quantity of heat required to raise the temperature of 1 gram of water 1 degree celsius
What is a Calorie?
aka kilocalorie = 1000 calories
What is the basal metabolic rate (BMR)?
the minimum level of energy required to exists
Normal = 65-70 calories/hr
What does the CNS integrate inputs from?
Long term energy stores
Short term meal related signals (nutrients and gut-derived satiety signals)
What reduces food intake?
Positive energy balance induced by overfeeding inhibiting the rewarding properties of food while enhancing meal-induced satiety
What are the CNS adaptive responses to energy deprivation?
Increases the rewarding properties of food
Reduces the response to satiety signals
What is leptin?
Leptin plasma levels are proportionate to body fat stores and act on key nuerons that regulate energy balance
What does the brain do in response to acute and chronic energy deficiency?
Increases the availability of fuel to CNS by increasing feeding or increasing hepatic glucose production by increasing glucagon and corticosterone
Conserves energy by suppression of HPT axis
What is the amount of carbs you should be eating per day?
45-65% of daily calories
What is the amount of protein you should be eating per day?
10-35% of daily calories
What is the amount of fat you should be eating per day?
20-35% of daily calories
What is the dietary reference intake for carbs per day?
130 grams
What packs the most energy per unit weight?
Fat at 9 calories per gram
