There are a few different options here. I'm going to describe them step-by-step so it is easier for someone who hasn't used the site in a while to follow.
One option is to use the graphical report.
1. Go to My Trackers and select "Reports."
2. Click on "Calories & Nutrients Over Time."
3. Change the calendar icon next to "Start date" and using the arrows next to the calendar, navigate to a date that you believe is prior to when you stopped using the site (for example, July 4, 2011) and select it.
4. Change the calendar icon next to "End date" and using the arrows next to the calendar, navigate to a date that you believe is prior to when you stopped using the site (for example, October 15, 2012)
5. Make sure the circle to the left of "Daily" increments is checked.
6. Click "Run Report."
7. There you will see a graph with red triangles (if there are no triangles, no tracking was performed in that time range, so go back to step 3). Hovering over one of those triangles will tell you the date and clicking on it will give you a summary of the items tracked on that day.
Use the SparkSummary Calendar.
1. Go to "My Trackers" and then click on "Reports."
2. Select "My SparkSummary Calendar" under the "Weight and Other Reports" section.
3. Click the button for "Previous Month" until you see a date with calories recorded.