Dates of Publication
Surveys are conducted quarterly:
March, June, September and December
Cost of Food at Home for a Week in Alaska
March 2002
Up to three stores in each of 20 communities were surveyed during March of 2002 for the cost of a specific set of food and non-food items. The 104 food items selected were taken, with some modification, from the USDA Low-cost Food Plan which is itself based on a nationwide survey of eating habits of Americans, conducted in 1977-78. In addition, the costs of such items as water, propane and electricity were collected. All costs were adjusted to reflect local sales tax where applicable.
The estimated prices of unavailable food items in various communities were calculated as the expected cost as judged from the prices of all available items relative to the price of those items in Anchorage. The percent of foods unavailable in each community are shown in the survey.
Weekly food consumption rates for a family of 4, children 6 - 11 years, form the basis of the expressed food costs. All other costs are ratios of that cost as calculated from the USDA Cost of Food at Home survey issued March 2002. The cost for this family of 4 can be calculated from the table by summing the individual members. For smaller families such a sum would be too low and should be adjusted up by 20%, 10% or 5% for families of 1, 2 or 3 persons respectively. Similarly, the sum for larger families would be too high and downward adjustments of 5% and 10% are suggested for 6 and 7 or more member families. These adjustments reflect that some economies may be realized when preparing foods for larger families.
Rows 19 through 23 represent historical food costs. The Anchorage column is a comparison of present to previous Anchorage costs. Similarly the U.S. Average column represents changes in U.S. average prices. A one (1) appearing in the Anchorage column indicates that the current Anchorage cost is 1% higher now than at that date. Therefore, rising food costs are indicated by positive values. The remaining columns are each community's cost relative to Anchorage at that date. For instance, a cell containing a one (1) indicates a community that was experiencing a food cost 1% higher than Anchorage at that date.
Calculating
Daily Energy Requirement
The
first detailed estimates of human energy requirement (kilocalories or
Calories) were published by Harris and Benedict in 1919, which
remains the defining work on the subject. There are many factors,
which affect energy needs including, age, sex, weight, physiological
status such as pregnancy or lactation, level of activity and illness.
Consequently, any calculation of energy requirement is only an
estimate. Knowing the precise energy requirement of an individual
would only be useful if the precise energy value of foods were known,
which in general is not so. It is possible to look up energy content
of food in tables, but the food you have in hand, say a peanut butter
sandwich, may not be composed of the identical ingredients used in
the analyses and therefore will not have identical or even closely
similar energy content. Furthermore, the food label now seen on all
food packages has estimates of energy that are based on table values,
the food in the package was not analyzed, only estimated. In general,
the energy value on a food label is assumed to be accurate within
15%. In short, a calculated human energy requirement may be entirely
adequate given the lack of uncertainty in application.
The
simplest means of calculating energy requirement is to assume 30
kcal/kg as a daily requirement for a sedentary person. The typical
person is taken to be 70 kg (154 pounds, 2.2 lbs/kg), so the daily
requirement would be 2100 kcal (the Calorie on a food package is a
kilocalorie and as such should always be capitalized). Subtract 100
kcal from the total for each 10 years of age over 30. For a 50 year
old, 2100 - 200 = 1900 kcal per day. For individuals with a lifestyle
of moderate activity, start with 35 kcal/kg, or 40 kcal/kg if engaged
in sports.
In 1932 Max Kleiber published a means of
calculating the daily basal energy requirements for any animal,
humans included, also based on weight. Basal energy is the heat
released from a fasted, lying animal. It is an excellent point for
comparison among animals, but requires additional work for use at a
practical level. Here, energy per day (kcal/day) is calculated as
70W3/4 , where 3/4 (0.75) is the exponent on weight
(kilograms). This is easy enough to do if you have a modern
calculator. For those familiar with logarithmic tables or who have a
slide rule, the calculation is not difficult, otherwise you will be
doing the cube and two square roots of weight by hand. The 70 kg man
in this case will require 70 x 703/4 = 1694 kilocalories
per day as a basal energy intake. Basal intake does not take into
account the energy required to eat or digest food (add about 10%),
nor other normal daily activities of even a sedentary person. I'll
skip these interesting theoretical calculations and move on to the
use of the more practical Harris-Benedict equation.
The
Harris-Benedict equations reflect the important factors of basal
energy demand listed in paragraph one, excepting activity level that
is not part of the basal demand. The equations are:
Men,
energy per day (kcal/day) = 66.5 + 13.8(weight in kg) + 5(height
in cm) - 6.8 (age in years)
Women,
energy per day (kcal/day) = 655.1 + 9.6(weight in kg) + 1.8 (height
in cm) - 4.7(age in years)
For
a 70 kg man, 175 cm tall (5 feet 9 inches), aged 25, the
Harris-Benedict equation predicts: 66.5 + 13.8(70) + 4(175) -
6.8(25) = 1738 kcal/day.
Adding in the energy demands of
physical activity requires some judgment, but for starters, add 20 to
40% for sedentary activity (mostly sitting), 55 to 65% for light
activity (moving about and daily walking), 70 to 75% for moderate
activity (lots of moving about and some daily vigorous exercise) and
80 to 100% for heavy activity (daily exercise program). For the
example above, assuming moderate exercise, the energy requirement for
moderate activity (70% increase) would be 1738(0.7) = 1217 kcals. We
add that to the basal requirement to arrive at a daily-required
energy intake of 1738 + 1217 = 2955 kcals. If such an individual
consumed fewer calories than this, he would loose weight, or would
gain weight if he slacked off on exercise or overate.
Sources:
Harris, J.A. and F. G. Benedict, 1919. A biometrical study of basal metabolism in man. Carnegie Inst. of Wash. Pub. 279.
Kleiber, M. 1932. Body size and metabolism. Hilgardia 6:315.
Perspectives in Nutrition, 4th Edition, 1999. WCB/McGraw-Hill
Submitted By:
Bret R. Luick
Foods & Nutrition Specialist