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Lemons (one whole 108g) contain 12 grams of carbohydrate and almost no fat.
Some of that carbohydrate (5.0g) is fiber which means that lemons have pretty much no fat and a moderate amount of carbs.
They have 1 gram of protein in a whole serving and tons of nutrients. Fruit is usually frowned upon when it comes to weight loss but moderate amounts are generally fine.
A lemon a day as the saying goes, has never been cause for anyone to gain weight or to not 'lose' any bodyfat.
You would need to eat about 100 per day to maintain your body weight so technically I guess it's possible to gain weight with lemons if you were to eat 120+ /day, everyday, but good luck with that feat.
Eat and be healthy.
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