Supposedly underweight people may initially lose, but toward the end could actually gain. Just drink the maximum lemonade and try to be inactive. Just my opinion tho...

I also am a little underweight. In 6 days of the Lemonade Diet I lost about 1 lb. Be careful to not do too much! I was too active (tried a short hike in high altitude) on the 6th day of my fast and ended up getting hypoglycemic. I guzzled tons of lemonade, but had a hard time recovering & had to make the decision to end my fast early. I say go for it! Just lay low & drink lots of lemonade! To your health!

just add more maple syrup. you are going to lose all the weight of food build up in your intestines. so dont freak out if five pounds melt away.
also drink more lemonades with the extra syrups (12)

Try drinking more of them than most of us do. You can drink a dozen if you like.