Welcome to the forum.There are possibilities that you could be suffering from gastric
ulcer,oesophagitis,haital hernia or postpandial dysmetabolism,heart problems,arrythmias,postprandial
hypotension etc.In post prandial dysmetabolism ,after eating sugary and fatty foods lot of damging free
radicals are released in the blood stream which cause damage to the body causing symptoms of
fainting,dizzness,plapitations etc.Postprandial hypotenion occurs due to diversion of blood flow to digestive
tract causing hypotenion.For correct diagnosis you need a complete workup of blood tests,USG of
abdomen,electrocardiogram,endoscopy,Holter montoring of the heart.Please consult a physician ASAP.best luck!