Molecules in food contain chemical energy that cells use to produce ATP. Food also supplies raw materials your body needs to build and repair tissues.
why do we need to eat?
we eat to gain energy
food supplies raw materials used to build and repair body tissues
both of the above
neither of the above
nutrients are substances in food that supply the energy and raw materials your body needs for growth, repair and maintenance.
the nutrients that the body needs include:
water, carbohydrates and fats
water, carbohydrates, fats and minerals
water, carbohydrates, fats and proteins
water, carbohydrates, fats, proteins, vitamins and minerals
water is the most important nutrient because:
every cell in the human body needs water
many of the body's processes including chemical reactions take place in water
water makes up the bulk of blood, extracellular fluid and other bodily fluids
water can be lost from the body when you sweat, in urine and with every breath you exhale
humans need at least 1 liter of fluid each day
all of the above
simple and complex carbohydrates are a major source of energy
fats help the body as they
absorb fat soluble vitamins
are part of cell membranes, nerve cells and certain hormones
when there are only single bonds between the carbon atoms in the fatty acids, each carbon atom has the maximum number of hydrogen atoms and the fat is said to be
saturated
unsaturated
these fats have one or more double bonds between carbon atoms which reduces the number of hydrogen atoms in their fatty acids.
saturated fats
unsaturated fats
these fats are usually liquid at room temperature, such as vegetable oil
unsaturated fats that are modified by adding hydrogen to them or processed are
trans fats
these fats are solid at room temperature and have a longer shelf life
because many vegetable oils contain more than one double bond, they are called
polyunsaturated
proteins have a variety of roles in the body including:
proteins supply raw materials for growth and repair of structures such as skin and muscle
many enzymes that control chemical chemistry by increasing the rates of chemical reactions are made of proteins
proteins have regulatory and transport functions (e.g., insulin is a protein that regulates blood sugar levels and hemoglobin, a protein found in red blood cells helps transport oxygen )
proteins can be used as energy sources when other nutrients such as carbohydrates are in short supplu
proteins are polymers of amino acids
the body is able to synthesize 12 of the 20 amino acids used to make proteins and the other 8 are called essential amino acids
organic molecules that the body needs in very small amounts are called vitamins
most vitamins are needed by the body to help perform chemical reactions
there are two types of vitamins
fat soluble and water soluble
unsaturated and saturated
these vitamins are fat soluble
A,C, D, E
A, D ,E, K
water soluble vitamins include
C, D,,B
C, B
fat soluble vitamins can build up small deposits of these vitamins for future use, but water soluble vitamins dissolve in water and cannot be stored in the body and therefore should be included in foods eaten each day
inorganic nutrients that the body needs usually in small amounts are called minerals
a balanced diet provides nutrients in adequate amounts and enough energy for a person to maintain a healthful weight
food labels can be used to choose healthful foods because:
they provide general information about nutrition
they provide specific information about the product
they can be used to determine if you are consuming enough of some of the important vitamins and minerals
none of the above
when using food labels it is important to remember that percent daily values are based on a 2000 calorie diet
people who are more active than average have greater energy needs and when a person stops growing or becomes less active their need for energy decreaes
these factors contribute to the rise of obesity in the US over the last several decades
inactive lifestyles
high calorie diets
The American Heart Association recommends a diet with a maximum of 30% of calories from fat, of which only 7% should be from saturated fats and 1% from trans fats
fat contains about 9 calories per gram and carbohydrate and protein contain 4 calories per gram
foods that contain a high amount of any type of fat are high in calories
