Healthful Nutrition for Fitness and Sport

Essential Nutrients

p Definition

n Nutrients that the body needs but cannot produce at all or cannot produce in adequate amounts

p Include:

§ Fiber

§ Linoleic fatty acid and alpha linolenic f.a.

§ Essential amino acids

§ Water and fat soluble vitamins

§ Minerals

§ Water

Essential Nutrients

p Macronutrients

n Nutrients that provide energy and growth, usually taken in large quantities (CHO, Fat, Protein, Water, some Minerals and electrolytes)

p Micronutrients

n Nutrients that help regulate metabolic processes taken in small quantities (Vitamins and Minerals)

Non-Essential Nutrients

p Definition

n Nutrients found in foods or the body can make on its own

p Examples include:

§ Simple CHO

§ Drugs

§ Phytochemicals

§ Food extracts

§ Herbs

§ Antinutrients (adversely affect nutritional status)

How are dietary intakes determined?

p Scientists establish the Recommended Dietary Allowances (RDA) based upon:

n The amount of the nutrient that prevents a nutrient-deficiency disease

n The amount of the nutrient that may reduce the risk of a specific health problem or chronic disease

n The amount of the nutrient that may increase health risks

Recommendations for Nutrition

p RDA

n Represents average daily dietary intake that is sufficient to meet nutrient requirements of nearly all (97-98%) health individuals in a group

p Dietary Reference Intakes (DRI)

n Will replace and expand upon the RDA. It is a joint project between the U.S. and Canada.

The Balanced Diet

p Balance focuses on 6 categories

Food Guides

p Food Guide Pyramid – developed by USDA

Food Guides

p Redesigning the Food Guide Pyramid

(according to Willett)

Food Guides

p Food Exchange System – developed by Am. Dietetic Assoc, Am Diabetes Assoc, & other government health organizations

n Focus was on identifying number of calories within each of the 6 food categories so that appropriate diets could be set up for:

p Diabetics

p Weight Control

n Example:

p 1 starch contains 15 grams of CHO, 3 grams of protein, 0-1 grams of fat, and 80 calories. This “amount of nutrients” is in a slice of bread, which can be exchaged with ½ cup of cooked cereal (has similar amount of nutrients) or ½ bagel

Key-Nutrient Concept

p If you consume an adequate amount of the 8 key nutrients, you will most likely receive an ample supply of all nutrients essential to humans

p The 8 key nutrients

n Protein

n Vitamin A

n Thiamin

n Riboflavin

n Niacin

n Vitamin C

n Iron

n Calcium

Nutrient Density

p The amount of nutrients per food item. The higher the number of nutrients, the higher the nutrient density is similar caloric value foods. Objective – eat high nutrient containing foods of less caloric content

p Which of the following has a higher nutrient density?

n 3 oz tuna with 118 cals, 24 g protein, 0.8 mg iron

n 3 oz clams with 126 cals, 22 g protein, 24 mg iron

Food Guides

p Food Pyramid and Food Exchange lists are not perfect

p Several other food guides for various ethic, age, and food preference groups exist

p General purpose

n Provide simpler approach to proper nutrition

Terminology of Health Status

p Morbidity

n Defines # of incidences of disease states within a large population

p i.e. # of Americans out of 1,000 diagnosed with

diabetes in 1990

p Mortality

n Defines # of deaths per type of disease state or condition in a population

p i.e. # of Americans out of 1,000 who died from

cardiovascular disease in 1990

Dietary Guidelines to Reducing Risk of Chronic Disease

p Balance food intake with physical activity

p Eat variety of foods

p Choose diet moderate in total fat, low in saturated fat (<30% total fat, <10% sat. fat)

p Choose foods rich in complex CHO’s and fiber (55-60% of caloric intake)

p Choose beverages and foods that moderate your intake of sugars (should be < 10 % of caloric intake)

p Choose and prepare foods with less salt and sodium (< 2,400 mg/day)

Dietary Guidelines to Reducing Risk of Chronic Disease

p Consume alcoholic beverages in moderation (1 drink per each 50 pounds of body weight)

p Maintain a moderate protein intake (0.8 grams/kilograms of body weight which approximates 50-60 grams/day or 10% of caloric intake)

p Choose diet adequate in calcium and iron

p Practice food safety (e.g. proper storage and preparation)

p Avoid excess food additives and dietary supplements

p Enjoy your food

The Diet Fads

p Popular Diet Fads

n Atkins Diet (Robert Atkins, M.D.)

n The Zone (Barry Sears, Ph.D.)

n Paleolithic Prescription (Boyd Eaton, M.D.)

n Ornish Diet (Dean Ornish, M.D.)

The Diet Fads

p Atkins Diet (introduced in 1972)

n Theory

p CHO’s are culprit behind obesity, not fat. CHO’s turn into fat with excess consumption. If deprive body of CHO’s it will burn fat.

n Diet

p High fat, low CHO

n Pros

p Good for quick weight loss

p Dieters feel full and satisfied

n Cons

p Saturated fats increase heart disease risk

p Cutting out fresh produce reduces vitamins/nutrients

p Tend to regain weight + more if going off diet

n Candidates

p People looking to lose weight quickly

The Diet Fads

p The Zone (introduced in 1984)

n Theory

p Encourages dietary balance. Diet stimulates more ideal production of insulin to subsequently assist weight loss.

n Diet

p 30% protein, 30% fat, 40% CHO

n Pros

p Encourages eating lean protein sources with less sat. fat

n Cons

p Makes it difficult to determine food portions

p It is calorie-restrictive

n Candidates

p Athletes; allows them to stay in “Zone”

The Diet Fads

p Paleolithic Prescription (introduced in 1988)

n Theory

p Farming made us fat due to the intro. of refined grains.

n Diet

p Cut out grains, like white flour

p Return to fruits and vegetables

p Avoid fatty grain-fed beef in favor of lean meat

n Pros

p Reduces use of “processed” cereals

n Cons

p Grain-rich diets not proven to ineffective

n Candidates

p Individuals interested in pursuing natural lifestyle

The Diet Fads

p Ornish Diet (introduced in 1990)

n Theory

p Use of more vegetables in meals reduces incidences of cardiovascular disease.

n Diet

p Only 10% of calories from fat

p High fiber plan (vegetables, beans, whole grains, fruit can be eaten until full)

p Low-fat dietary products and egg whites (in moderation)

p Avoid meats, oils, olives, sugar when possible

n Pros

p Reverses risk of heart disease

n Cons

p High CHO, very low fat diet may lead to obesity

n Candidates

p Individuals with high cholesterol, high BP, CV risk factors

Nutritional Recommendations for Better Physical Performance

p Nutrition Goals: prior to competition

n Allow for stomach to relatively empty prior to start of competition

n Minimize gastrointestinal distress

n Avoid sensations of hunger, lightheadedness, and fatigue

n Provide adequate fuel, primarily CHO, in blood and muscles

n Provide adequate amount of water

Nutritional Recommendations for Better Physical Performance

p Nutrition Principles associated with Sport

n For events in morning, eat precompetition meal similar to breakfast (500-600 calories)

n For events in early morning to mid-afternoon, eat breakfast and lunch. Breakfast could be slightly more substantial

n For events in late afternoon, eat breakfast, lunch, snack. Breakfast can be substantial, along with lunch. Eat snacks when appealing, i.e. fruit, bagel, and other digestible foods

n For events in evening, eat breakfast, lunch and a precompetition meal for dinner.

Use of liquid meals/sports bars/supplements for competition?

p Liquid meals are well-balanced in nutrition with high CHO, no bulk, easily digested and absorbed, and more economical

n Examples:

p Nutrament

p Gatorpro

p Ensure

p Ensure-Plus

p Slim-Fast

n Approximate 250-400 calories; may lack vitamins and minerals

n May be taken 2-3 hours prior to competition

Use of liquid meals/sports bars/supplements for competition?

p Sports bars

n Good sources of CHO, with some protein and fat in variable amounts

n Advantage is convenience

n Primarily used as a substitute for precompetition nutrition, not long-term use in a diet

p Dietary Supplements

n Not proven to be potent ergogenic aid

Importance of Breakfast in Sports

p Considerations:

n Should eat a balanced, nutrient-dense breakfast

n The breakfast should provide significant amount of calories

n A breakfast high in fiber with an average amount of protein will prevent onset of mid-morning hunger

n Avoid refined CHO, like doughnuts

p May trigger insulin response resulting in hypoglycemia (low blood sugar); may make you feel tired and sluggish

A Good Balanced Breakfast

p The following items provide a substantial portion of RDA:

n Skim milk

n Poached egg (boiled egg, avoids frying in oil)

n Whole-grain toast

n Fortified high-fiber cereal

p Fortify – to add one or more nutrients to a food so that it contains more of the nutrients than were present before processing

§ e.g. Milk is fortified with Vitamin D

n Orange juice

Skipping Breakfast for Sports?

p Comparable to small fast

n May result in hypoglycemia with symptoms of weakness and possible impairment of performance

n In research study:

p Breakfast of 100 g of CHO improved cycling performance by 36% over “no breakfast”

Eating during competition?

p Not necessary in short duration sports

p Endurance sports will require:

n Water for hydration and control of body temperature

n CHO for additional energy, in some cases

p Ultradistance

n May require hypotonic salt solution

Eating after competition?

p In most cases, a balanced diet will restore nutritional status following competition

p After long duration events;

n Should encourage complex CHO in diet

p Complex CHO are rich in energy to replace used glycogen

p Complex CHO are rich in vitamins and minerals

Do gender and age affect nutritional recommendations?

p Men and women who eat balanced diets generally can meet their energy needs

n Women may need more iron, particularly in aerobic events

p Young athletes

n Calories, CHO, micronutrients, and water have been found to be deficient in many cases

p Older athletes

n Should find nutrient-dense foods; calorie requirement is less due to ↓ metabolic rate

Traveling Nutrition

p Select foods high in CHO, low in fat, & moderate protein

p Pack food and fluids in traveling bag or cooler

n This allows you to eat pre-event meals at appropriate time

p Many restaurants can offer good choices

n Possibility of fast-food options, also

p Should choose sandwiches containing less than 30% of calories from fat (e.g. McDonald’s McGrilled Chicken)

p For grilled, skinless chicken sandwiches, much of fat is in sauce put on sandwich; ask for sauce on the side

n Review nutritional guides provided by restaurants in pamphlets or on-line