The ecologic validity of fructose feeding trials: supraphysiological feeding of fructose in human trials requires careful consideration when drawing conclusions on cardiometabolic risk

Vivian L Choo; John L Sievenpiper

doi:10.3389/fnut.2015.00012

The ecologic validity of fructose feeding trials: supraphysiological feeding of fructose in human trials requires careful consideration when drawing conclusions on cardiometabolic risk

Front Nutr. 2015 May 6:2:12. doi: 10.3389/fnut.2015.00012. eCollection 2015.

Authors

Vivian L Choo¹, John L Sievenpiper²

Affiliations

¹ Department of Nutritional Sciences, Faculty of Medicine, University of Toronto , Toronto, ON , Canada ; Toronto 3D Knowledge Synthesis and Clinical Trials Unit, Clinical Nutrition and Risk Factor Modification Centre, St. Michael's Hospital , Toronto, ON , Canada.
² Department of Nutritional Sciences, Faculty of Medicine, University of Toronto , Toronto, ON , Canada ; Toronto 3D Knowledge Synthesis and Clinical Trials Unit, Clinical Nutrition and Risk Factor Modification Centre, St. Michael's Hospital , Toronto, ON , Canada ; Division of Endocrinology and Metabolism, Department of Medicine, St. Michael's Hospital , Toronto, ON , Canada.

Abstract

Background: Select trials of fructose overfeeding have been used to implicate fructose as a driver of cardiometabolic risk.

Objective: We examined temporal trends of fructose dose in human controlled feeding trials of fructose and cardiometabolic risk.

Methods: We combined studies from eight meta-analyses on fructose and cardiometabolic risk to assess the average fructose dose used in these trials. Two types of trials were identified: (1) substitution trials, in which energy from fructose was exchanged with equal energy from other carbohydrates and (2) addition trials, in which energy from fructose supplemented a diet compared to the diet alone.

Results: We included 64 substitution trials and 16 addition trials. The weighted average fructose dose in substitution trials was 101.7 g/day (95% CI: 98.4-105.1 g/day), and the weighted average fructose dose in addition trials was 187.3 g/day (95% CI: 181.4-192.9 g/day).

Conclusion: Average fructose dose in substitution and addition trials greatly exceed national levels of reported fructose intake (49 ± 1.0 g/day) (NHANES 1977-2004). Future trials using fructose doses at real world levels are needed.

Keywords: HFCS; cardiometabolic risk; dose; fructose; meta-analysis.