Vyvanse is a central nervous system stimulant used to treat symptoms of attention-deficit hyperactivity disorder, or ADHD. Side effects can include trouble sleeping, dry mouth, nausea, diarrhea, anxiety and loss of appetite. You can prevent unwanted weight loss due to loss of appetite by keeping your calorie intake constant and choosing the right foods.
Consume frequent small meals instead of two or three large meals to add extra calories to your diet.
Eat healthful foods like whole grains, fruits and vegetables, low-fat milk and dairy products, lean protein sources, nuts and seeds. Don't try to maintain or gain weight by eating unhealthy, high-calorie, high-fat foods.
Consume heavy, thick breads like whole wheat or pumpernickel, which have more calories, according to the University of Illinois at Urbana-Champaign.
Increase healthy fats like corn oil margarine, olive and canola oils, peanut butter and salad dressings made with olive oil. Limit saturated fats.
Drink smoothies or shakes made with milk or juice. Sprinkle in some ground flaxseed, recommends MayoClinic.com. Flaxseed is high in fiber and omega-3 fatty acids.
Choose apple, cranberry, cranapple, grape, pineapple or apricot juices. They have more calories than grapefruit, orange and tomato.
Eat healthy, calorie-dense snacks. MayoClinic.com recommends nuts, peanut butter, cheese, dried fruits and avocados.
Try adding calorie-dense foods to traditional recipes. For instance, add cheese to casseroles, salads, sandwiches or scrambled eggs.
Choose sweets that also contain nutrients, such as bran muffins or yogurt.
Exercise regularly. Exercise can stimulate your appetite and strength training can build muscle, adding weight.