Hi Jennifer so glad you found my blog. From personal experience, I have found my clients to be most successful re-challenging foods if we test small amounts of the foods and go slowly and methodically. For instance, when challenging fructose, we may start with 1 tsp of honey…and test this amount for 3 times in one week…unless the person develops symptoms. Then we may add in 1/2 a mango with the honey the following week. Challenge foods should only contain the FODMAP you are testing.(So apples are NOT a good challenge food as they have excess fructose and sorbitol!) When re-challenging mannitol, simply try 1/2 cup of mushrooms. Best to you!

FODMAPs are simply not black and white for a number of reasons. Lists do vary as the “cut-off” levels have only recently been developed and not all practitioners were/are on the same page plus food concentrations of FODMAPs vary depending where the food was grown and in what conditions the food was grown. Food grown in drought conditions will vary in fructans compared to the same food grown in ideal conditions so as much as we would love a FIRM list–it is somewhat of a moving target. The key is to minimize not eliminate all FODMAPS and sometimes we lose sight at that very important concept!
Best!