The assumption that 3,500 calories equals one pound of body fat is the basis of numerous weight loss plans.
Your body weight remains stable when the number of calories you consume is equal to the number of calories you expend.
These diets assume that consuming 3,500 less calories than you expend will allow you to lose one
pound of bodyfat, while consuming 3,500 calories more than you expend will result in a one pound gain.
However, the January 2010 issue of The journal of the American Medical Association (J.A.M.A.) points out a major shortcoming in this theory:
When you gain or lose weight, the baseline number of calories your body needs also changes. The excess calories you consume are used to build new tissue, which then requires additional calories to maintain.
JAMA illustrates this finding: If you eat an excess of 60 calories every day, you will initially gain weight, but after a few years, this gain will taper off at around six lbs. when your body stops using these excess calories to create new fat tissue and starts using them to maintain your new, heavier weight instead.
Furthermore, JAMA’s research suggests that making small changes to your diet may not be enough to sustain any long-term weight change.
They note: “The 90th percentile of BMI is 35 for men aged 50-59. To reach this degree of adiposity from a BMI of 25 at age 25, an individual would need to increase energy intake, decrease physical activity, or both by 680 kcals per day. ”
This finding has both positive and negative implications.
First, you no longer need to worry about small indulgences.
“An extra 100 calorie cookie once in a while doesn’t make a dent in that daily 680 calorie excess.”
However if your goal is to lose additional weight, this may be more challenging than your initial weight loss.
As you lose weight, your body needs less calories to maintain your new size.
So, you will need to create an even larger caloric deficit to continue shedding pounds.
This research drives home the fact that to sustain a change in weight over time, you need to eat healthy foods you enjoy eating and a gym routine you love to make an effective lifestyle change.