Can having gastritis cause you to not lose weight?

I don't think so but: I don't know how or why having gastritis would directly prevent weight loss.The best way to lose weight is a healthy diet (ideally low in sugars and starches) & exercise.If gastritis somehow prevented you from eating healthy foods it could be a factor, but you should be able to eat healthy even with gastritis. However, gastritis is an inflammatory condition & inflammation may contribute to obesity.