When you enter what you have eaten, try only useing the "search food" bar. Don't but it in the bottom on the "Quick Calorie Entry" also. If the food is in both spots it doubles the amout it thinks you ate.
That's not a problem I'm familiar with; you might go to the Improve MedHelp Suggestions forum and see if the mods can help you.
You can access that forum via the following link.
http://www.medhelp.org/forums/Improve-MedHelp-Suggestions/show/110