I have two parts to this question

I'm wondering how many calories is in a whole peanut butter and banana sandwich.

And if I eat one everyday, how much weight would I gain?

Hello fenderstrummer28

1 - As per this link it's 329 calories (http://www.calorie-count.com/recipe/18953.html)

2 - Unless you would also eat other foods you would drop weight. If you gain or lose weight depends on the total calories you take each day. As long as the total is less than approx. 1500 cal. you lose weight. And if it is more than these 1500 cal you gain weight.
It is as simple as that.

The only way you can influence that is by increasing your energy use by walking, running, cycling etc.

:>)

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