unit 1 quiz 1: nutrition and health Flashcards
why do we eat food?
we need to
our brains and appetite
physiological reasons
physical influences and needs
Psychological Influences and Needs
social influences
emotional influences
why do we simply need to eat food
Food provides the fuel/energy/calories the body needs to survive.
Calories = energy we get from food, When people talk about the calories in food, what do they mean? A calorie is a unit of measurement — but it doesn’t measure weight or length. A calorie is a unit of energy. When you hear something contains 100 calories, it’s a way of describing how much energy your body could get from eating or drinking it.
Sugar is the easiest way to give your body energy, ex. Refined sugars, white sugar, corn syrup = high energy really fast.
Fatty foods = energy reserves, used to help when starving
Multiple bodily systems, like the circulatory, respiratory, neurological and endocrine systems, run automatically, and need energy to function.
So we are genetically programmed to eat when food is available as protection against starving, which would cause these systems to shut down.
Humans are hard-wired to eat fatty, sugary, high calorie foods because they have the most energy
More energy = a better chance of survival.
what does eating have to do with our brains and appetite
Neural receptors in the brain receive hormones like ghrelin & leptin into the brain which can regulate appetite.
Ghrelin, produced in the stomach that tells us when to eat.
tends to be released on a schedule
can be triggered by smells
blood levels of ghrelin tend to be highest before mealtimes, and return to low levels after mealtimes.
Leptin - hormone made by adipose cells
Cholecystokinin (CCK) is produced in the stomach and upper intestine to alert the brain to feeling full.
Triggered by sensors/receptors in the stomach, goes to the brain and other parts to say to start digesting food.
It sends a short term message to the brain telling us to stop eating through stimulates the vagus nerve
The vagus nerve extends from the brainstem and is involved in the control of several bodily functions, including digestion.
Leptin is produced by adipose tissue, or body fat.
helps regulate the body’s energy, in the form of fat stores, over the longer term.
does not have as direct of an impact on food intake from meal to meal as ghrelin
Counters ghrelin (as it can suppress appetite)
Hungry- Ghrelin (high) Leptin (low) Full- Ghrelin (low) Leptin (high)
why do we eat for physiological reasons
Genetics- We are programmed to eat!
hormones
maintain health
genetic preferences (sensitivity to taste)
Lifestage - Nutrient needs vary at particular stages in life
Body of the mother produces fats and sugars in breast milk for babies.
Really old people need calcium, fibre.
Adolescents need diversity of fats and nutrients for the brain.
why do we eat for physical influences and needs
Availability of resources Availability of food Geography, climate, soil, water farming technology transport & storage of food political stability store location Income level/education level Time (for food prep.) Skill level (comfort in preparing food)
why do we eat for Psychological Influences and Needs
Sense of security
comforting to know you have food
can create a feeling of being cared for
Someone wanting to eat with you, dates, parties, etc.
Sense of belonging
creates a social bond between people
welcoming visitors, celebrations, life events
Sense of providing/taking care of others
sense of contributing to the family or group
enjoyment in fulfilling other people’s needs (nourishing people)
making others feel happy and welcomed/belonging
Bringing bottles of wine, food, gift cards, etc.
what do social influences have to do with why we eat
Culture → Beliefs & customs of a group of people
Religious influence
Traditions (historical & seasonal)
Ex. pumpkin spice lattes, seasonal corn, large meals for special occasions
Ethnicity-common blood, land, race
Food norms (eggs & bacon for breaky)
Food taboos (not eating certain foods)
Ex. health reasons, mental health reasons, religious reasons, certain diets
Family (which is influenced by the culture) Values, beliefs, attitudes & traditions Lifestyle (single parent? Working?...) Education Preferences (of members)
Peers - eat similar foods
good & bad influence
often socializing includes food
Media - ads, TV, internet, social media, coupons, samples
what do emotional influences have to do with why we eat
mood and stress levels connecting to food
Mood
Stress
Memories (positive/negative connected to food)
Comfort food
eating is a ____ experience
multi sensory
what senses are involved with food?
- Visual effect of food
- Feel of the food in our mouth - crunchy, smooth
- sound of the food in our mouth - expectation of how something will taste vs. reality
- flavour of the food - taste, smell, feel, surrounding environment/atmosphere
- surrounding environment or atmosphere.
taste and smell are ……
survival mechanisms
– a way to test food or other substances before they enter the body.
Evolution is very prominent in these ideas. When we taste sour or spicy foods enter our mouths, it could be bad for us ex. Plant hormones, sour/spoiled food.
Sugary foods = good source of quick energy, we know it since it tastes sugary and we know what sugar does.
Bitterness -
Bitter and sour = could mean poison
Sweet = high energy carbohydrates
Salty = essential minerals
We need salt, used for electron balancing for neurons
Umami (savoury ex. Meats, cheeses, mushrooms, broths) = protein/ fat (long term energy stores)
We like these because proteins are long term energy storers in case of starvation.
what % of our taste is actually smell?
Smell helps us detect - dangerous odors
- ripe and rotten fruit.
95% of what people describe as “taste” is actually our sense of smell
Our true taste sense happens only in the mouth
how does taste work?
The surface of the tongue is covered with papillae
Papillae contain taste buds - not the bumps on our tongues, but inside our tongues, those are papillae
Taste buds contain taste Taste Receptor Cells (TRC)
TRC have tiny openings called taste pores that contain “taste hairs”
“taste hairs” react to 5 different tastes: they have all taste receptors inside of them
- sweet
- salty
- sour
- bitter
- umami (savory)
Chemicals from food dissolve in our saliva before they enter the taste pores and are detected by the taste hairs
Breaking down food in mouth allows food to communicate with taste hairs.
Taste signals travel through nerve pathways up the brainstem to the gustatory complex (area responsible for perceiving taste, not smell). Taste pathway (TRC to nerves to brain, up the brainstem and to GC).
how does smell work?
Olfactory receptors detect scent molecules in the air and send signals to the olfactory bulb in the front of the bulb.
Not 5 different tastes, like a million scents in our environments
Aromatic - gives off a strong smell, ex. Garlic,
Olfactory bulb is enveloped by the emotional area of the brain, The Limbic System making a very strong connection between scent and memory.
The Limbic system is our emotions and long term memories are. Scent and memory are very closely related.
Can protect us, ex spoiled milk scent.
how does our sense of touch play a part in our tasting experience?
Sensing spice, temperature & texture
Signals are sent along the trigeminal nerves responsible for sensations in the face and mouth.
