160 Calories
That is the number of excess calories that I had to eat per day to gain 124 pounds.
When I learned that a pound fat contains about 3,500 calories I realized I could calculate the number of calories per day I had to overeat to gain weight. I just needed two reference dates where I knew what my weight was.
On 5/25/1998 my weight was somewhere around 200 pounds. I know that because that is my third daughters birthday. The spring before she was born I lost about 60 pounds on the Atkins diet.
On 10/28/2005 my weight was 324 pounds. I know that because that is when I permanently changed my lifestyle and started losing weight again.
324 - 200 = 124 pounds 5/25/1998 - 10/28/2005 = 2,713 days
In 2,713 days I gained 124 pounds. That is just an average of course. Some times I gained weight faster. Some times my weight even stabilized for a period of time. And at the beginning of 2005 it even dropped a few pounds. But that doesn't matter. The simple fact is that over a period of 2,713 days I became 124 heavier.
124 pounds / 2,713 days = 0.0457 pounds/day
I gained 0.0457 pound per day. That is just 20.7 grams. To put that in perspective, a AA battery weighs 25 grams.
Now I know how many pounds per day I gained. Since I know how many calories are in a pound of fat I can calculate the number of excess calories I ate per day to gain 124 pounds.
0.0457 pounds/day X 3,500 calories = 160 calories/day
A single serving, or 1/2 cup, of vanilla ice cream contains about 150 calories. When I realized that I only had to reduce the number of calories I was eating by 1 small bowl of ice cream per day I knew I'd never be fat again.