I Dr. Lavoie's Guest Lecture - Nutrition and the Digestive System
Overview of the Digestive Process
Ingestion
Digestion
Absorption
Metabolism
Good health - balance of good nutrition and exercise
Nutrition - quality of foods based on energy contained in food and contribution to the body's chemical and energy needs
Chemicals involved in body maintenance
Chemicals involved in energy
Chemicals involved in growth (until puberty)
Chemicals involved in preventing disease
No single chemical can do it all
Need a variety of foods and food groups
Balance of foods from these food groups
Moderation or amount of intake of foods from the different food groups
6 Major Food Groups
| Group | Use | Essential/Non-essential |
| Vitamins | Water and fat soluble vitamins with a variety of uses depending on which vitamin | Essential because the body can't make them |
| Minerals | variety of uses depending on which mineral | Essential because the body can't make them |
| Water | Makes up the cyptoplasm of cells, plasma of blood, etc. | Essential - too little causes dehydration, too much causes edema and leads to cardiovascular diseas, 8x8 rule (8 glasses of 8 oz/ day = 64 oz/ day intake on average) |
| Carbohydrates | glucose for short-term energy, stored as glycogen in animals, fiber from cellulose for digestion | Non-essential, body can convert glycogen in glucose but there must be constant intake for fuel (body will use up other reserves if no carbs are in the diet) |
| Lipids and Fats | long term energy storage, highest source of energy | Liver can make cholesterol but not Omega fats, must eat foods (e.g., tuna fish) with these fats |
| Proteins | enzymes and muscle mass, can not store in body | Body can make 11/20 amino acids, must eat foods with the other 9 amino acids, must eat proteins to replace proteins lost to normal use |
Getting it Right - Compiled by HHS (Health and Human Services), USDA (US Dept. of Agriculture)
Dietary Guidelines (adjusted every 5 years to take into account the latest scientific findings)
Calories = units of energy in food
1 Calorie = 1000 calories = 1kCal
1 calorie = energy needed to raise 1 ml of water by 1 degree C
Calories and exercise: 4-9-4-7 rule
1) proteins - 1g burns 4 cal (multiply the number of grams by 4)
2) fats - 1g burns 9 cal (multiply the number of grams by 9)
3) carbohydrates - 1g burns 4 cal (multiply the number of grams by 4)
4) alcohol - 1g burns 7 cal (multiply the number of grams by 7), energy rich but nutrient poor
Food Pyramid is a guide from the Government
Suggested foods and amounts based on your age, gender and physical activity level
Variables that affect the amount and types of Nutrients in your diet (see pyramid also)
Age
Gender
Activity level
Climate
Health
State of nutrition (general health)
10 Dietary Guidelines
1) Aim for healthy body weight - measured by BMI
BMI = weight in kg/height2 (in m2)
Healthy BMI 19-24 Overweight BMI 25-29 Obese 30+ 2) Increase physical activity
3) Let pyramid guide your food choices
4) Choose a variety of grains (especially whole grains)
5) Choose a variety of fruits and vegetables
6) Keep food safe - cook safely and store safely
7) Choose diet in low or unsaturated fats (plant oils or omega-3, omega-6 found in fish)
Bad fats - saturated or animal fats
Trans-fats - plant oils that have been hydrogenated
8) Moderate intake of sugars in beverages (especially sodas)
9) Minimize use of table salt (NaCl) - leads to water retention and cardiovascular disease
10) Alcohol in moderation - high energy (see above) but low nutritional content
Blackboard at Saint Anselm College
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Copyright © 2001 Jay Pitocchelli. All rights reserved. The contents of this page are the intellectual property of Dr. Jay Pitocchelli for distribution to students enrolled in General Biology BI 01 at Saint Anselm College. These pages may not be copied, photocopied, reproduced, translated, or published in any electronic or machine-readable form in whole or in part without prior written approval of Jay Pitocchelli. Students enrolled in General Biology BI 01 at Saint Anselm College have permission to print this material for their lecture notes. The images linked to this web page are the sole property of Addison Wesley Longman Publishers™.