Bloated stomach can be due to several things but is usually due to wind. This can cause a lot of discomfort as well as passing wind either from below (from the rectum) or by belching. The wind is usually the air you have swallowed; this is normal but some people swallow more air, if they are anxious or eat fast. Wind can also be produced by vegetables, e.g. beans. Vegetarian diets produce more wind. Wind is difficult to treat, but people have tried charcoal biscuits, etc. It is also part of the irritable bowel syndrome and peppermint tablets can help. Also, I suggest that you take more exercise as this will help with your trying to lose weight.