You might be baffled by how much sugar you consume every day because it's in everything from baked beans to tuna, bottled water to low fat milk.
Kiwi mum Amanda Tiffen discovered this herself - working out she was ingesting 30 teaspoons of sugar day while trying to eat healthy.
"Fat doesn't make you fat, sugar makes you fat," Ms Tiffen says.
But before this discovery Amanda thought she had tried it all.
"I'd actually given up. When the documentary came along - is sugar the new fat? I had given up at that stage," Amanda says.
"I felt that I should've known but especially the low fat foods, I felt like that had been sold to me by society that that was healthy but most or quite a few of the low fat goods out there are full of sugar," Ms Tiffen says.
Armed with a new understanding the mother of two took a new tack and began a life of less sugar.
"As it started to work, I got from size 16 down to size 14 and I went out and bought a whole new wardrobe, ditched the size 14 that was out the door, and I thought 'wow this is awesome'," she says.
But she didn't stop there.
"Then I got down to size ten and I was like well I'm seriously not going to go any lower than this so what did I do?" Amanda says.
"Went out and bought a whole new wardrobe and at this point my husband's going 'oh no, here we go again'".
"Then eventually I got down to size 8 and I thought 'okay well that's enough, I'm going to buy another wardrobe but that's it, no more.'"
After two decades of discomfort, Ms Tiffen dropped four dress sizes and twenty kilos in just nine months.
"It was disbelief, complete disbelief that it actually worked," she says.
Then Ms Tiffen gained a group of followers, like her friend Leigh who ended up losing even more weight than her.
The two of them have combined to tell their story.
Despite flunking English at school, Ms Tiffen's written a book featuring Leigh's low sugar recipes.
"So most of the recipes in the book are actually our family recipes that have been handed down like from my grandmother and what have you," she says.
The book is a best seller with over 19,000 copies sold here and in Australia, with a reprint on the way.
How sweet is that?