Page 91 - Nutrition Essentials for Nursing Practice

CHAPTER 4 Lipids 79

as avocado and nuts, are also listed in other groups (fruit and protein foods, respectively),
but because the overwhelming majority of their calories comes from fat, their fat content
is supposed to be counted as part of the oil allowance. For instance, avocado is a fruit, yet
80% of its calories come from fat. Eating half of a medium avocado counts as a serving of
fruit and as three teaspoons of oil, which is about half of a typical adult’s daily oil allowance.
Other examples of oil equivalents are as follows:

1 tbsp vegetable oil Equivalent to this amount of oil
1 tbsp soft margarine
2 tbsp Italian dressing 3 tsp
2 tbsp peanut butter 2½ tsp
1 oz nuts 2 tsp
½ oz sunflower seeds 4 tsp
3–4 tsp
3 tsp

DIETARY REFERENCE INTAKES

The issue of how much of each particular type of fat is needed, how much is optimal, and
how much is too much is complex and in some cases controversial. Fats that the body can
synthesize—namely, saturated fatty acids, monounsaturated fatty acids, and cholesterol—
do not need to be consumed through food. Trans fats provide no known health benefits,
and so they are not essential. As such, neither an Adequate Intake (AI) nor Recommended
Dietary Allowance (RDA) exists for any of these fats. The reference values that have been
set are discussed later in the text.

Total Fat

Neither an AI nor RDA is set for total fat due to insufficient data to define a level of total fat
intake at which risk of deficiency or prevention of chronic disease occurs (National Research
Council, 2005). An Acceptable Macronutrient Distribution Range (AMDR) is estimated to
be 20% to 35% of total calories for adults (Fig. 4.7). Generally as total fat intake increases,
the amount of saturated fat increases; therefore, limiting total fat intake to 35% of total
calories or less is prudent in order to limit saturated fat intake.

According to National Health and Nutrition Examination Survey (NHANES)
2007–2008 data, the average intake of total fat for both men and women aged 20 years
and older is 34% of total calories (USDA, Agricultural Research Service [ARS], 2010). This
translates to a mean intake of 95.3 g/day for men and 67.3 g/day for women.

Saturated and Trans Fat

The National Research Council, Institute of Medicine recommends that the intake of both
saturated fat and trans fat be as low as possible within the context of a nutritionally adequate
diet (National Research Council, 2005). Because the risk of heart disease increases incre-
mentally as saturated fat and trans fat intake increase, a Tolerable Upper Intake Level (UL)
could not be defined.