Scientific American presents Nutrition Diva by Quick & Dirty Tips. Scientific American and Quick & Dirty Tips are both Macmillan companies.

Q. Is there an online database that breaks out the soluble and insoluble fiber content of foods? I recently read about a study that stated if you consume at least 10 grams of soluble fiber a day it is helpful in reducing belly fat. However, online databases only seem to list total fiber only. Any ideas?

A. I hate to burst this bubble, but I’m afraid this study has been widely misreported by the media. Many people came away with the impression that by eating 10g of soluble fiber per day, you can expect to reduce belly fat by 3.7%.

Here’s what the study actually found: Over the course of 5 years, the amount of belly fat in these subjects increased by an average of 12%. Those who ate more soluble fiber gained belly fat more slowly. For each additional 10g of soluble fiber people ate, the rate at which they accumulated fat was 3.7% slower. In other words, all other things being equal, an extra 20g of fiber could reduce your five-year gain from 12%  to 11%. (By the way, in terms of heading off the dread belly fat, exercising 5 times a week is twice as effective as eating an extra 10g of soluble fiber each day.)

Continue reading on