The following was written and shared by Juliette Gibson (@julietteelizabeth) in our IIFYM Postpartum and Breastfeeding group on Facebook. 30 June 2020
A client this week asked an important question about fiber, and in writing my response - I realized this is something that a lot of ladies might benefit from learning more about!
With all of our clients, Kristina and I recommend that you aim for a minimum of 25-30g of fiber per day... But, we go one step further and specify that these fibers should come from WHOLE FOOD sources, and not added fibers in processed food items. Seems simple right? Eat more vegetables and you'll be fine... But what constitutes a "whole food" in this sense? And why does it matter? When you're looking at the fiber content of an item, you want to be paying attention to the fibers naturally found in the ingredient(s). For some things, this is simple - 100g of raspberries has 6.5g of fiber. 100g of asparagus has 2g of fiber. 100g of plain canned black beans has 5.5g of fiber. These are simple and easy to find in the USDA database... But what about bread? Is that a whole food? In short - YES! For these purposes it's 100% whole food and an excellent source of fiber... if you choose the right kind, specifically whole grain bread that has the fiber-containing parts of the wheat included. Ok, so that one is easy enough... but what about something more "processed" - surely the new protein pasta that are popping up on the market don't count, do they???
Indeed they do! When we're talking about the context of fiber, as with so many things in nutrition - the important thing to do is look at the label. For this example of Barilla Protein Plus Pasta, when you're looking at the list of ingredients, the first several items that make up the bulk of the product (semolina, lentils, chickpeas, etc.) are all foods that naturally contain fiber, so in this case - the fiber is naturally occurring and definitely counts. But for example, when you're looking at a Quest bar... The fiber source here is isomalto-oligosaccharide or IMO. IMO is found in some plants naturally, but it's inefficient and costly to extract these natural sources. So when it's listed like this, it has been manufactured from starch using an enzymatic process which negates all of the natural benefits of this fiber when it is in nature - most notably the lack of an insulin response. Since this form of fiber is derived from starches, it is not a preferred food source for those with insulin sensitivities such as diabetics or those with IR-PCOS. But this synthetic version is cheap to produce (and in fact is made from waste materials left over from other processing of corn derivatives) and has a sweet taste from the starches it's made from, so it's often used to help cut down on the amount of real sugar used (in this case along with erythritol, steviol glycosides, AND sucralose) and bolster the "fiber" content of the processed item in question.
The FDA is in the process of determining whether isolated and synthetic fibers provide a beneficial physiological effect to human health, but these claims are widely disputed in the nutrition and health industries because much of the research supporting them is directly funded by the processing manufacturers that stand to make tremendous financial gains from their inclusion. Until this ruling can be finalized labeling guidelines allow manufacturers to treat these artificial ingredients as a fiber source.
Due to some, unfortunately (purposefully) vague language by the FDA, food manufacturers are also allowed to remove the fiber components of a processed item when calculating total calories (which is why the math never adds up quite right in MFP for so many things!) even though fiber doesn't *actually* contain zero calories, it's just slightly less than the 4cal/g of other types of carbohydrates. Depending on the fiber source, the true caloric load is between 1.4-3.3cal/g - but given that this is such a small difference when you're talking about thousands of calories per day and only a few dozen at most being affected, we recommend just treating fiber like any other carb and rest assured that the difference in calculations won't have ANY impact on long term progress. These types of "fake" manufactured synthetic fibers can hide under a lot of different names though, so some of the main ones to look out for are: Isomalto-Oligosaccharides/IMO (powder or syrup) Prebiotic Fiber VitaFiber Inulin Chicory Root/Extract beta(2-1)fructans Dahlia Extract/Inulin Fructo-Oligosaccharides or Fructooligosaccharides Long-chain Oligosaccharides
Isolated beta-glucans Galactomannans Isolated lignin Low methoxylated pectins Ispaghula husk Modified cellulose Methylcellulose Propylcellulose Resistant dextrins
As another precaution, several of these can cause digestive problems for people if consumed too frequently or in too large of quantities. Polydextrose for example is dextrose that has been fused with sorbitol, an artificial sweetener well known for causing a laxative effect for many people. :-)