Even more dense fruits like avocados can be good, have your food with a heavier dip/sauce, try cooking with healthy oils like olive oil because it won’t make you feel as sick as regular oil (tbh you can straight up have a spoon of it before a meal ik many people who did that, have calorie dense granola for breakfast, make smoothies (idk why they are usually advertised for weight loss they are super calorie dense lol. With enough fruits and dates u can easily make a smoothie that is 500 cal and take a few sips every while so its not too heavy)
Sorry if its a bit long but yeah this helped people ik who struggled with gaining weight so hopefully it helps u