Affiliations: Center for Advanced Research in NeuroGastrointestinal
Disorders, Columbus, OH 43205, USA | Center for Healthy Weight and Nutrition, Columbus, OH
43205, USA | Nationwide Childrens Hospital, The Ohio State
University School of Medicine and Public Health, Columbus, OH 43205, USA | Department of Biological Sciences, Capital University,
Columbus, OH 43205, USA
Note: [] Corresponding author: Frederick W. Woodley PhD, Nationwide
Children's Hospital, 700 Children's Drive, Columbus, Ohio 43205, USA. Tel.: +1
614 722 6413; Fax: +1 614 722 3454; E-mail:
frederick.woodley@nationwidechildrens.org
Abstract: Background: Despite a dearth of well-controlled studies comparing
the gastric emptying (GE) of casein- and whey-based formulas in humans and lack
of clear evidence suggesting that such a difference influences patient
symptoms, prevailing opinion among healthcare professionals continues to
purport that a clinically meaningful difference exists between the two. Aim: To review the literature related to the influence of casein and whey on
GE in humans. Methods: A PubMed literature search was executed using a
combination of the following search terms: gastric emptying, human, casein, and
whey. Our primary interest was experimental design strategies with respect to
established physiologic factors controlling GE. Results: Our search
resulted in 11 citations; 5 directly compared GE rates of casein- and
whey-based formulas and 3 of the 5 suggested a difference. Critical review of
these studies revealed numerous experimental design weaknesses that included:
1) lack of control over osmolality, caloric density, feeding volume and
macronutrients (protein, fat, and carbohydrate), 2) small sample sizes, and 3)
use of heterogeneous subjects with respect to age, symptom types, symptom
severity, and general health status. Conclusion: No convincing evidence
exists to support the prevailing notion that casein- and whey-predominant
formulas differently influence GE rates.
