One problem with ketogenic and other ultra-low-carb diets is the lack of fiber. Besides the obvious internal benefits, fiber intake is closely associated with fat loss and a desirable body composition. A study reported in the journal Appetite showed just how powerful of an ally fiber can be during a diet. In the experiment, subjects on a reduced-calorie diet were given either a placebo or a fiber supplement before meals.
When ingested, the fiber slows down the digestion of food increasing the feeling of fullness. The group who was given the fiber reported that their hunger was reduced by one-third, they felt less hungry after the small feeding, and were less inclined to snack between meals. The dose for each subject was 6.8 grams of psyllium fiber, and the researchers used the brand Metamucil, which is available in most grocery stores.