As I prep for the ABOM (American Board of Obesity Medicine) board exams, I am coming across some nuggets that I find fascinating. I'd like to share them in these quick posts.

At the recent ASBP conference I attended, nutrition professor Chris Melby spoke about the differences in calorie "harvesting" that occur between one person and another. For example, your gut flora may determine whether you extract more calories from food than someone else does...or whether more of these calories are wasted and not processed. It is also possible that on a cellular level, certain people process energy less efficiently, leading to more wasted energy and less than is available for storage. We have known for many years that when we overfeed people to the same degree, some will gain a lot of weight, while others will gain very little. Experiments with twins done by Claude Bouchard showed that within twin pairs, the amount and distribution of gain was very similar. This indicates that genetics influences what we do with the calories we eat. However the concept of harvesting leads us to believe that, while a calorie may be a calorie, it is not accessible in the same way to each person.