Filler ingredients, which are ingredients added to a supplement just to increase the total weight/volume of that supplement, include things like low quality whey concentrate, dextrin, glucose, artificial sweeteners, thickeners, gums, sugar and so forth.
While these may help boost the weight of the protein powder, thus satisfying the ‘5 pound tub’ requirements in order to slap a price tag on the bottle, they are doing nothing to improve your results. In fact, they often are hard to digest and can leave you suffering from bloating, flatulence, as well as gastrointestinal distress.
What’s more is that these ingredients may also raise the glycemic load of the protein powder, which increases your risk of gaining body fat upon eating it. Don’t think that just because the protein powder contains few grams of sugar that means it won’t impact blood glucose levels.
In addition to increasing blood glucose levels, many also cause other unwanted side effects including headaches, migraines, as well as depression, gastric distress, and weight gain.