Here's an interesting study that found that different people have different blood glucose reponses to the same foods.

http://news.meta.com/2015/11/19/cell-nutrition-is-personal-i...

>Participant A maintained a stable blood glucose level after eating a cookie but responded with elevated glucose levels after eating a banana. Conversely, participant B experienced an increase in blood glucose level after eating a cookie, but not after consuming a banana.

>In another striking example one of the participants, a middle-aged woman who was obese and pre diabetic learned that her “healthy” eating habits may have actually been unhealthy for her. The researchers found that in her case, eating tomatoes resulted in an “unhealthy” blood sugar spike, as the woman ate tomatoes frequently over the course of the week long monitoring period, this “healthy” habit may have been undermining her health.