•Nutrition is a study of the interactions occurring between you & food. •Nutrients – about 45 substances that provide energy, structure or regulation of body processes. •Essential nutrients- need them, but can’t make them or fast enough. •Macronutrients- need in large amounts (carbohydrates, fats/lipids, proteins – provide energy/calories) •Micronutrients – need in very small amounts (vitamins, minerals- no energy/calories) •Phytochemicals- another category in plant food- not essential but have health promoting properties. Metrics used in nutrition
1 kilogram (kg) = 2.2 lbs
1 tsp hold about 4 g of sugar or salt and 5 ml liquid
1T = 3 tsp
1 L is a little more than 1 qt (4 cups)
Energy content(in kcal) : carb=4 /g; prot = 4; fat=9; alcohol=7 We need nutrients, but we eat food. Foods are not good or bad in themselves. Combined they make up a healthy (or not), diet. No one food by itself contains all the nutrients in the appropriate amounts needed for best growth and health. THERE IS NO ONE PERFECT FOOD. Everyone needs same nutrients. Do they need the same amount??
How healthy is the American diet??
How do we make food choices??
We eat the foods we like, can afford, food that is available, foods that are culturally acceptable and then what we think we should eat. Americans are influenced by what they see on TV and read in popular press.
Availability of food is a big factor- can you get to the supermarket, $$$, storage place, place to cook, know how to cook, lift packages when get home, do you have allergies, health problems, HBP, diabetes?
Scientific method: hypothesis, theory, experimental controls, control groups, placebo, double blind study, peer review. Science is NOT based on anecdotal stories told to the popular press by someone who wants to sell you a book or a product. "Good nutrition research studies should have at least 50 participants and control groups (and preferably thousands in the study). The nutrients intake should be controlled and adequate nutrient consumption data should be available through food diaries. The final statistics should show significant results. The levels of food consumed in the study should be amounts that people can reasonably eat in a day ". The study needs to be repeated.
Questions to ask when judging nutrition claims: does the information makes sense, where did info come from, were the experiments well designed, can the info be applied to humans, who is making the recommendation and who stands to benefit????
Is this experiment valid??
Eight healthy male college students who regularly weight train were studied in 2 grps. One grp took Power Boost supplement while other grp received a placebo. After 3 weeks the subjects were asked how energetic they felt. The people in the experimental grp reported higher energy levels. It was reported in the Muscle magazine that Power Boost improves strength.
Besides scientific nutritional controversies, there are 4 underlying problems: 1.Under the first amendment, anyone can write a nutrition book that is completely FALSE, which means that many nutrition books published should be listed under books of fiction. 2.If you call a product a "food supplement", you can sell anything in the so called "health food" stores or pyramid style or with an 800 number. If the product is not labeled a food or a drug, it falls between the cracks of the Food & Drug Adm rules and regulations, is not covered by law, and may be untested or uninspected for health safety or sanitation. 3.Anyone can call themselves a nutritionist. There is no reliable national organization that certifies "nutritionists". 4.Research scientists go public with their results before they have published or before their theory has been proven. One study does not prove that a theory is a fact. The media picks up the story - everyone believes that this is a proven fact.
Qualified nutrition health professionals