Hi and welcome to HCM!
Thanks for posting your query here.
When food undergoes catabolism in the body it releases energy and it is stored in the body. This process is called oxidative phosphorylation. The excess energy is stored in the adipose tissue. In some people the oxidation of the food is not followed by the phosphorylation. So the energy is released as excess heat from the body. This happens in people having more brown adipose tissue
. Other than the excess heat no other affects are identified untill now.
Even if they have excess food obesity is rare in those individuals. I think you will be having a lean body. So to compensate the water loss in excess heat you need to take a lot of fluids. In general it is not related with the foods what you take. It may be a coincidence.
For the gastric upset you can use some H2 blockers like Ranitidine
Hope this is helpful to you.