Eat high-calorie fruits, like avocados, bananas and
dried fruits. Add
dried fruit in the same places you add nuts. Mix
dried fruits with nuts, too, for a healthy trail-mix snack. Add pieces of dark chocolate to it adding more calories and antioxidants.
Add more calories to vegetables. Don't be tempted to avoid vegetables because their fiber is filling, but they're low in calories. Vegetables are an important part of a healthy diet.