The New Calories per Pound of Weight Loss Rule
"The New Calories Per Pound
of Weight Loss Rule" If the "3500 calories per pound"
weight loss rule is bunk, what's the alternative? How many fewer calories
do you have to eat, or how many more do you have
to burn, to lose a pound of fat? There are validated mathematical
models that take into account the dynamic changes that
occur when you cut calories, such as the metabolic slowdown, and they've been turned
into free online calculators that you can use to make
personalized estimates. There's the Body Weight Planner
from the National Institutes of Health and the Pennington Biomedical Research
Center's Weight Loss Predictor out of Louisiana State University. Here are the two direct links. Here are some shortened URLs
(in parenthesis under each link) The NIH Body Weight Planner has
been found to be more accurate, since the LSU model appears
to overestimate the drop in physical activity, but they both have
their own pluses and minuses.
The Body Weight Planner tells you
how many calories you need to restrict and/or how much more
exercise you need to do to achieve a specific weight
loss goal by a specific date. If you click on the "Switch to Expert
Mode" button you can get a graph, and exportable chart showing your
day-to-day weight loss trajectory. So if you're a middle-aged,
sedentary average height woman, obese at 175 pounds, who wants to be
closer to her ideal weight within a year, 2000 calories a day would
prevent future weight gain, about 1400 calories a day would
bring your weight down like this, and then you could maintain that
lower weight at 1700 calories a day. If, in addition, you
walked a mile a day, it would give you a little
more calorie leeway. The LSU Weight Loss Predictor,
on the other hand, doesn't allow you to tweak
physical activity, but the advantage is that you don't have to
choose a goal or time frame.
Just put in different calorie changes
and it graphs out your expected course. Is there any easy rule
of thumb you can use? Yes. Every permanent 10-calorie
drop in daily intake will eventually lead to about
one pound of weight loss, though it takes about a year to achieve
half the total weight change and about three years to completely
settle into the new weight. So cutting 500 calories a day can
cause the 50-pound weight loss predicted by the 3500 Calorie Rule,
but that's the total weight loss at which you plateau,
not an annual drop, and it takes about
three years to get there. A 500-calorie deficit would be expected
to cause about a 25-pound weight loss the first year, and then an additional
25 over years two and three.
That's only if you can maintain
the 500-calorie deficit, though. If you're eating the same diet that
led to the original weight problem, but just in smaller servings,
you should expect your appetite to rev up about 45
calories per pound lost. So if you were cutting 500 calories
a day through portion control alone, before you were down
even a dozen pounds, you'd feel so famished that you'd be
driven to eat 500 calories more a day and your weight loss could vanish. That's why if you're dead-set on
eating the same diet, the same foods but just in smaller quantities, you have
to cut down an additional 45 calories per pound of desired weight loss
to offset your hunger drive. So to get that one pound off, instead
of just 10 calories less per day, using the 10 Calories Per Pound Rule,
you'd have to eat 10 calories less on top of the 45 less to account for the
revving of your appetite, so 45 +10 = 55. So just changing diet
quantity and not quality, it takes 55 calories less
per day to lose a pound.
So that 500-calorie daily
deficit would only net you about a 9-pound weight loss
over time instead of 50. That's why portion control methods can be such a frustrating
failure for so many people..
