Many dietary factors have been blamed for contributing to gastroesophageal reflux. Overweight is clearly a risk factor, although we still lack RCTs to show that losing weight will improve symptoms or lower the linked oesophageal cancer risk.
Some evidence supports the idea that certain foods (e.g. chocolate, coffee, alcohol, spicy food) can aggravate it. Although not consistent evidence, a trial of avoidance may be appropriate.