What do we know?

Language structures:Present simple: Do you think water is food

What do you think of slimming diets?Passive: The value is expressed in kilocalories.

Twelve of these are manufactured by the body itself …Superlatives: Water is the most abundant molecule in our bodies.Time expressions: Every day, once a week / month, a few times a week / month, etc.Infinitive of purpose: To maintain the activity of all our cells, … our bodies need energy.Use of gerund after prepositions: Basal metabolic rate is measured after resting …

DO NOW (INPAIRS):1.NAME FOODS THAT SUPPLY US ENERGY2.WHAT IS A CALORIE?

FACT OR FICTION3. Athletes need more protein in their diets than other people do

4. The only salt that a food contains is the salt that you have added to it

5. An apple a day keep the doctor away

6. Is a vegetarian diet healthier?

7. Any more?

Food Pyramid

What are nutrients?• Essential substances that your body

needs in order to grow and stay healthy

What is a Nutrient?

Nutrients

• Some provide energy. • All help build cells and

tissues, regulate bodily processes such as breathing.

• No single food supplies all the nutrients the body needs to function.

Nutrients in the Human Diet

• Macronutrients– Water– Amino Acids and Proteins– Lipids– Carbohydrates

• Micronutrients– Vitamins– Minerals

Six categories of nutrients:

Healthy Diets Require:

• Water

• Carbs, Proteins, Lipids, Amino Acids

• Vitamins:

- water-soluble (thiamine, riboflavin, folic acid)

- fat-soluble (Vitamin A, D, E, K)

• Minerals (Fe, Ca, P, Na, K)

Water• Solvent in which the chemistry of life occurs

– cell chemistry occurs in an aqueous medium– water carries essential nutrients to cells– water carries metabolic wastes away from cells– hydrolysis & dehydration reaction– stabilizes body temp

Sugars

Which simple sugars are found in the different types of food shown in the photo?

What types of food contain complex sugars?

Carbohydrates• Most of them are sweet.They provide us

energy and they are at: bread, rice, cereals, potatoes, …

• There are 2 types:

• - simple carbs: glucose and fructose, easy to be digested and absorbed

• - complex carbs: starch, made up of glucose, and cellulose or fibre, useful to prevent constipation and keeping low levels of collesterol

Wheat Seed:

contains

Wheat Seed:

contains

There are some people that can not absorb gluten, a protein

contained just on wheat, they are called celiac and they must eat corn flour products instead of

wheat

Lipids

What are the different groups of lipids?

Are some lipids more healthy than others? Why or why not?

Lipids• Triglycerides (Fats)

– energy storage molecules– protect and cushion delicate body organs– source of the raw materials for the

construction of phospholipids– unsaturated versus saturated fats

Lipids• Saturated Fats

– Solid at RT– Milk, cheese, meat– Not good for you– Bounds C-C

• Unsaturated Fats– Liquid at RT– double bounds C=C– Canola, olive, peanut oil– Better choice

Lipids• Steroids (e.g., cholesterol)

– precursor molecules for steroid hormones, vitamin D, bile salts

– fundamental component of plasma membranes (influence membrane fluidity)

– HDL-cholesterol versus LDL-cholesterol– We have to eat some lipids but not too

much and mainly non saturated fats (olive or vegetable fats)

Proteins

• Enzymes • Structural proteins (shape and

form of cells and tissues)• Hormones• Immunoglobulins (antibodies)

Essential Amino Acids we MUST eat them:• Tryptophan• Methionine• Valine• Threonine

• Phenylalanine• Leucine• Isoleucine• Lysine

• Histidine(infants)

Are vegetarian diets complete and

balanced?:they can be, but vegetarians have to eat milk, cheese, nuts and other seeds. Eggs or fish can be good for

babies and young people too

Vitamins• Organic compounds needed by

the body in small, but essential amounts

• Cannot be synthesized by the body in sufficient amounts

• Function in a variety of ways in metabolic reactions

• Thirteen known vitamins

Water-Soluble Vitamins

vsWater-Insoluble

Vitamins

Water-Soluble Vitamins

Pantothenic acid

Biotin

B12 (cyanocobalamin)

Folic acid

C (ascorbic acid)

B1 (thiamin)

B2 (riboflavin)

Niacin

B6 (pyridoxine)

Water-Insoluble Vitamins

A (retinol)DEK

Minerals

• Essential inorganic elements• Involved in a variety of

metabolic processes• Major minerals versus trace

minerals

Major MineralsCalcium

PhosphorusMagnesiumSodiumPotassiumChlorine

Trace Minerals

IronIodineFluorideZincCopper

Manganese

Cobalt

Selenium

Chromium

Osmosis

Describe how the three illustrations show the process of osmosis.

How is osmosis related to nutrition?

• An animal whose diet is missing one or more essential nutrients.

Giraffe eats bone to get phosphorus nutrient

Malnourishment

Giraffe eats bone to get phosphorus nutrient

• Impaired cognitive development

• Won’t attain full height

• More susceptible to disease and infection

Malnourishment

Energy needsWe obtain energy from nutrients, through metabolism:

1gr fat = 9 kcals

1gr carb = 3.75 kcal (aprox 4)

1gr protein = 4 kcal

Thedaily basal metabolic rate is the energy required to maintain us in rest and good temperature. It can be calculated (page22). Try to do yours:

- Men: 66.5+(13.7xkg + 5xcm) – 6.7x age

- Women: 55+ (9.5xkg) + (4.8xcm) – 4.7xage

To this we have to add energy for physical activity

Try to find: mediterranean, celiac, high-fibre, low calories and vegetarian diets:

Food preservation helps to keep fresh food a long time without decomposition. Try to find the

followings (pp 28-29): cooling (freezing, refrigeration), heating (sterilisation,

pasteurisation, UHT), drying, vacuum packing, irradiation, fermentation, smoking, preservatives

(sugar, salt, vinager, species )

Compare these food labels and find out which one gives more information. Dou

you watch your food labels?

Watch your label and answer: Does it contain?:

Product and Company names

Quantity:weight or volume

Nutritional information:detailed amount of kcal, carbs, fats, fiber, proteins,

vits. … and % recommendedHow to store and how to use it (if necessary)

Best-before date and Expiry date