Does Eating Bananas Cause Belly Fat?

Bananas provide a lot of carbohydrates with virtually no fat. While bananas do provide many beneficial nutrients -- the fruit is rich in potassium, for example -- they may be more likely than some other foods to encourage belly fat gain. Bananas alone will not cause fat gain, but if you consume too many calories overall, you'll likely develop belly fat.

Calories

Consuming too many calories leads to belly fat gain, so the caloric density of bananas may contribute to fat gain. An 100 g banana contains 89 calories, which is significantly more than 100 g servings of other fruits contain; an 100 g apple provides 52 calories, while 100 g of watermelon contains 30. Because bananas contain more calories than these other fruits, they are more likely to push you beyond your maintenance level of calories and thus, belly fat gain.

Lack of Protein

Bananas contain minimal levels of protein. An 100 g banana provides just 1 g of protein, a nutrient most often associated with building muscle. Protein can also help you limit fat gain. A study published in the March 2011 edition of "Nutrition & Metabolism" found that decreasing the amount of protein in your diet relative to carbohydrates results in increased activity of fat-storing enzymes.

Rich in Sugar

While sugar provides flavor, not all of its effects are as sweet as its taste. Research performed at Massachusetts General Hospital indicates that consumption of large doses of sugar decrease testosterone production. As research from the June 2009 issue of "The Journal of Clinical Endocrinology and Metabolism" indicates, testosterone promotes fat loss, so the suppression of this hormone may encourage belly fat gain.

Type of Sugar

In addition to the amount of sugar, the type of sugar can have an affect on body composition. One of the most prominent sugars in bananas is fructose, which may encourage obesity compared to other sugars, according to research published in the January 2010 edition of "Physiology Review." Additionally, bananas contain sucrose, or table sugar, which can contribute to obesity and also counteract the anti-inflammatory action of fish oil, according to research from the June 2011 issue of the journal "PLoS One."

Lack of Fat

Bananas contain virtually no fat, as an 100 g banana provides less than .5 g. Despite the name of the nutrient, dietary fat may actually help you stave off fat gain. This is because fat provides feelings of fullness, so it can help you control your appetite and avoid overeating.