Physical activity is generally insufficient by itself to bring
about clinically significant weight loss. You lose weight when
your body is in negative calorie balance meaning that you eat
fewer calories than your body needs. You can create a calorie
deficit by: According to the Advisory Committee for the Physical
Activity Guidelines 2008 report1, it is tough to lose weight
only doing the second option. That’s because it takes quite a
bit of physical activity to create the large calorie deficit
that will yield significant weight loss. On the other hand,
relatively simple changes in food intake can create a large
energy decrease. For example, a 160 pound person who wanted to
lose weight could skip the cola drink (12 ounces = 150 calories)
or walk 36 minutes to burn off the same number of calories as
the soft drink. The same person could also not have the large
order of French fries (saving 540 calories) or walk for over two
hours to burn off the same amount of calories. That’s a lot of
walking! Who has the time