Fruits have nearly three times the calories per serving as vegetables, making them an effective way to add nutritious calories and gain weight. Some fruits are more watery and fibrous, which only fill you up so you can't eat additional calories. Choose starchy fruits or avocados, which have a naturally-occurring healthy form of fat. Achieve weight gain by boosting your daily calorie intake; eat 259 to 500 calories over and beyond what you burn to gain 0.5 to 1 pound a week. Add extra fruit to your diet gradually though, as large amounts may cause intestinal upset in some people.
Fresh Fruits for Weight Gain
Tropical fruits are a calorie-dense choice when you're trying to gain weight. One cup of sliced banana, for example, has 134 calories; a cup of pineapple chunks offers 83 calories, and a cup of fresh mango has 99 calories. Both pineapple and mango have a good dose of vitamin C, and mango also provides a fair amount of vitamin A. These fruits make better calorie choices when you're trying to gain weight than a cup of sliced apples, which has just 57 calories.
Berries, although often recommended on weight-loss plans, are also a source of added calories. Add them to cereal, smoothies or plain yogurt for a calorie boost. A cup of fresh blueberries provides 84 calories, and a cup of fresh raspberries has 73 calories. Berries do pack more fiber than the tropical fruits, especially raspberries, with 9 grams per 1-cup serving. If you have a light appetite, the fiber may fill you up and discourage you from getting enough calories at meals and snacks.
Dried Fruits for Weight Gain
Dried fruit is a non-messy, convenient way to enjoy fruit as a snack. The water has been evaporated from them, so they don't fill you up as fast, but their calories are concentrated. For example, a cup of fresh grapes contains about 105 calories, but a cup of raisins contains around 435 calories. A cup of dried apricot halves provides 313 calories, and just one date has 66 calories.
Dried fruit doesn't bruise when packed in a backpack or purse as a quick snack option. If you're not up for snacking on the fruits alone, add them to oatmeal, salads or mix them with nuts for a trail mix to increase the calorie and protein content in each serving. One cup of trail mix can contain almost 700 calories and 20 grams of protein.
Don't Forget Avocados and Olives
Two fruits, avocados and olives, contain healthy monounsaturated fats, which makes them higher in calories than most other fruits. Avocado may be eaten like a vegetable, but it's a fruit that packs a solid number of calories. One cup of cubes comes in at 240 calories and 22 grams of fat, or consume it as a cup of pureed guacamole and consume 368 calories. Avocados also provide a wealth of nutrients, including potassium, vitamin E and folate.
Sometimes considered a condiment, olives are another fat-containing fruit. Two large black olives contain 10 calories and 1 gram of fat. A drawback to olives are their sodium content. Two large black olives contain 64 milligrams of sodium; 15 black olives gives you 20 percent of your day's sodium intake.
To add calories and healthy fats, top a sandwich or burger with sliced avocado or chopped olives; toss cubed avocado with mango for a fresh twist on salsa; puree avocado into a smoothie for extra creaminess or add cubes to salad. Chopped black olives make a savory topping for salads or scrambled eggs or toss whole olives with whole-grain pasta, cucumber chunks and grape tomatoes.
Sneaky Fruit Calories
Puree a mixture of fruits with yogurt, protein powder and ice to create a smoothie. This may be easier to drink with or between meals and can add hundreds of calories, especially if you add flax meal or nut butter too. Fruit juice also supplies a significant number of calories when consumed between meals. Look for 100-percent fruit versions, rather than cocktails blended with sugar and artificial ingredients. Frozen fruit and fruit cups may also be an option when fresh isn't available. Look for naturally-sweetened versions, though, rather than ones with added sugar.