Eating more fiber-rich foods, including fruits, is typically associated with weight loss, not weight gain. But if you're simply adding lots of high-fiber foods to your usual diet, and thus upping your overall caloric intake, you could experience weight gain. It's also possible that something else is responsible for an increase in your weight.
Fiber and Weight Gain
Americans don't always get as much fiber in their diets as they should. Men need between 30 and 38 grams of fiber per day, and women should consume 21 to 25 grams per day. While adding more of this nutrient to your diet is healthy, sometimes when people suddenly increase their fiber intake but forget to drink enough water, it leads to constipation. The backed-up waste could cause a temporary increase in weight until it clears your system. If you're not used to eating much fiber, increase your intake gradually to minimize the risk of side effects, such as bloating, constipation and gas, and make sure to increase your water consumption at the same time.
Fruit and Weight Gain
To gain 1 pound, you have to consume an extra 3,500 calories. This is usually a gradual process, as people typically don't eat this many extra calories in just one day. Even though fruits are nutritious, they still have calories. Should you simply increase the amount of fruit you eat without cutting anything else out from your typical diet, it could lead to weight gain, especially if you usually choose the higher-calorie fruit options, such as bananas or persimmons. Most Americans don't get the recommended amount of fruit in their diet, however, which is 2 cups of fruit per day for men and 1.5 to 2 cups per day for women.
Fiber and Fruit for Weight Loss
Fiber is more often associated with weight loss than with weight gain. For example, people who ate more fiber from fruits and vegetables over a 6 1/2-year study had smaller increases in waist circumferences in that time. In addition, people who ate more total fiber gained fewer pounds, according to the study, which was published in the American Journal of Clinical Nutrition in 2010. Increasing your fiber intake may help you lose weight, whether the fiber comes from fruit, vegetables or other healthy foods such as whole grains.
It follows that if you're trying to lose weight, you don't necessarily want to limit your fruit consumption. Increases in fruit consumption were associated with decreases in both weight and body mass index in a study published in Nutrition in 2010. This is most likely because most fruits have relatively few calories per serving and contain significant amounts of fiber, allowing you to fill up without consuming a lot of calories. For the best weight-loss results, eat fruit instead of a higher-calorie food. For example, eat fruit instead of your typical dessert, or if this isn't enough of a treat for you, eat half a serving of your typical dessert, topped with fruit.
Type of Fruit and Weight
The type of fruit you eat can also make a difference in weight gain. The healthiest options are fresh fruits and frozen fruits that don't contain any added sweeteners. Fruit juice, canned fruits in heavy syrup and dried fruits have more calories per serving and thus aren't the ideal choices for those trying to lose weight. For example, a 1/4-cup serving of dried peaches has 100 calories, while you can eat a whole large peach for just 70 calories, and 1/2 cup of canned apricots has 60 calories, but you can eat four whole apricots for just 70 calories. Orange juice has 122 calories per cup, but a whole fresh orange only has 70 calories and is more filling because of the fiber it contains.
Although increasing fruit consumption, in general, can help you lose weight, pears, apples and berries may be about twice as effective as many other types of fruit for weight-loss purposes, according to a study published in PLOS Medicine in 2015. Raspberries, blackberries and strawberries are also among the most nutrient-dense fruits, making them among the better choices for those trying to get all their essential nutrients without consuming too many calories.