Can gastroparesis cause weight loss?

Yes in advanced stag. Malnutrition due to poor absorption of nutrients or a low calorie intake suggest eating six small meals a day instead of three large ones. When a person has severe symptoms, a liquid or puréed diet may be prescribed.
Yes. Gastroparesis is slowed stomach emptying, and makes a person feel full for a longer time after meals. The person has less appetite and eats less, leading to weight loss (if he doesn't change to higher calorie foods, and if he doesn't decrease his exercise routine). A person who "feels full" for a long time should be seen by a doctor to be sure there is not another serious medical problem inside.