Flashcards in Chapter 4 Deck (36):
What are the two fundamental scientific foundations for understanding eating and obesity?
-theory of evolution
-physiochemical concept of energy
The change in inherited (genetic) traits or characteristics across generations in a species
-Energy is embodied in specific molecules that drive biological reactions (including mechanical movements like walking) that are essential for life
Who proposed the 1st comprehensive evolutionary theory?
What did the 1st comprehensive evolutionary theory suggest?
-that species evolved by a very slow process called natural selection
-also that species will change over a long period of time and may eventually become a new species
-Also proposed by Charles Darwin
-the heritable mechanism by which new species can evolve by competition or biological fitness, meaning more surviving offspring
-a segment of the genome that encodes a single heritable trait
-the smallest functioning unit
Global population and its driving force
-the global population recently just passed 7 billion people, double the number it was 40 years ago
-the driving force is technological innovation (medicine, agriculture etc)
-drive was NOT by any biological process of natural selection
-relatively recent evolved member of the hominid family
-earliest hominids appeared about 4.5 million years ago
-our current human species are homosapiens
-appeared in fossil records about 200,000 years Aho
- appeared 4 million years after the divergence of our hominid ancestors from apes
What is the progressive alteration of morphology?
-common theme of hominid evolution
-body shape or size, including erect stature and in particular the development of bigger brains
What distinguished homosapiens from their evolutionary ancestors and from other species?
-cultures and technology
What is the consequence of scientific progress?
-one consequence is the rate at which we have altered our own environment including areas like agriculture, urbanization, education, health, technology, and telecommunications
How much bigger is a humans brain compared to a chimps?
2-3 times bigger
At birth how much does a humans brain weigh?
-about 500 grams
-roughly 15% of a newborns mass
How much does a newborns brain account to the total energy budget or metabolic rate?
At what age does a brain reach adult size?
the age of 2
What are the highest energy foods?
-animal sourced food
Animal sourced food
Food that is directly derived from animals such as meat, milk, and eggs
What do we mean by "you are what you eat?"
We eat chemical energy and transform, store, and use that chemical energy to fuel our cells
How is energy similar to bank accounts?
There are inputs (deposits) and outputs (withdrawals)
What is an energy input
-food we eat
What is energy output
-some occur on a regular basis some are occasional
The balance in the account increases (energy is stored by the organism)
the balance in the account falls (stored energy is used or mobilized)
What happens when an energy account is depleted?
-below a critical level the organism will die of energy starvation
Optimal foraging theory
a general theory that individuals will adopt the best set of food acquisition behaviours in a given environment to maximize energy gain
how well the offspring of that individual survive
What is the formula for the net energy yield of food?
-net energy yield of food=metabolize energy minus energy used in foraging
Basal metabolic rate
what it costs to keep the body at rest
Relationships between basal metabolic rate and cost of exertion?
roughly proportioned to body mass
What is an effective way of reducing obligatory energy expenditure by increasing the energy yield for foraging?
obesity is the inevitable result of what?
an obesogenic (promoting) environment
an environment in which calorie dense food is available at low cost, thus promoting unhealthy foods
What is a opportunistic eater?
term that is used to imply optimal strategy for feeding is an uncertain food environment is to take advantage of each and every feeding opportunity that comes along