Fiber is filling and can assist with weight loss.

We all know that fiber helps lower cholesterol and the risk of colon cancer.  In my opinion, when it comes to losing weight, a straightforward piece of advice may be more helpful than all the diet books, exercise, calorie counting, and portion measuring put together: Eat more fiber.  

Fiber fills you up, and its expanding nature stimulates nerves to cause full feelings.   One supportive study looked at whether oat fiber has a positive effect on perceptions of satiety​[1]​.  This study indicates that B-glucan from oats stimulates satiety and reduces further feelings of hunger, and stops further eating.  Another study looked at guar gum fiber supplementation, and it showed that 2 grams of this soluble fiber resulted in a 20% reduction in calorie intake in these subjects​[1]​.  

One of the recent promising scientific findings is the compound leptin.  It has been proven that leptin is the compound that signals fullness or satiety in mice and likely all mammals.  One promising study that still needs more research looked at mice and cereal fiber.   The researchers found that cereal fiber induced the release of leptin in mice and reduced appetite​[2]​. Fiber causes a feeling of satiety in mice, and the question is whether it will work in humans.  

Liu did a retrospective study to look at fiber intake and obesity and found that fiber intake is inversely related to the rate of obesity.  Simply put, the higher the fiber intake, the lower the rate of obesity​[2]​.  Although it did not show that fiber can cause weight loss, it shows that women who take in less fiber are more likely to be obese.  Another study that is similar showed the same relationship in men, but it also looked at grain, bran, and cereal fiber​[3]​.  

The ADA 2006 Dietary Guidelines point to the benefits of a high-fiber diet​[6]​.  One of them was by Pereira, and it showed that fiber intake alone can increase weight loss​[4]​.   In this study, children lost weight with nothing more than adding fiber to their diets.  There are plenty of studies that indicate that weight may reduce with the addition of more fiber.  

The bottom line: Fiber is not a magical bean that will grow the weight-loss bean stock.  Weight loss is all calories.  That said, fiber makes you feel more full and may help you reduce your intake.  I recommend at least 35-45 grams of fiber per day while you are trying to diet.  Do I think it will work for all dieters? Absolutely not, but it does work for me.