Every moment of every day, our bodies need energy to keep going.
Energy is needed not only to move our muscles, but also to keep us
breathing, keep our heart beating, maintain our body temperature,
and to allow for many other bodily functions. Each day, we need to
consume sufficient energy in the form of food to fuel these bodily
functions. For many individuals, however, this energy amount is
relatively small and may often fall into the range of 1,500-1,800
calories per day. If an individual requiring 1,500 calories’ worth of
food consumes 1,500 calories’ worth of food, all is well and energy
balance is maintained. But if 1,600 calories’ worth of food are
consumed, energy balance is lost. In this hypothetical example
involving the consumption of 100 extra calories per day, not much
weight would be gained in a single day, or even over the course of a
week. But over the course of an entire year, this daily difference of
100 calories would add up to a 10-pound weight gain. That’s a very
delicate balance! Especially in the case of processed foods or fried
foods, few of us could accurately determine the difference between
a 600-calorie meal and a 700-calorie meal.
Physical exercise is also involved in our energy needs, but in slightly
different way than you might expect. While it is true that physical
exercisedirectly burns calories and increases our energy needs in
this way, it burns surprisingly few calories in the lives of many
individuals. Leisurely-paced walking, for example, tends to burn no
more than 5 calories per minute for many adults. While that amount
is important, it only translates into 100 calories of energy burning per
20 minutes of leisurely walking, or approximately the same amount
of calories found in one tablespoon of dry-roasted nuts. In other
words, 20 minutes of leisurely walking doesn’t buy us very much
room for additional food intake (while still maintaining energy
balance).
According to energy balance research, what is more important about
physical exercise is its role in building and maintaining our muscle
mass. Since muscle tissue is a relatively active type of tissue in our
Healthy Weight Loss Q&As