Effects of High- and Low-proteindiets on Inflammatory Profiles in People With Morbid Obesity: A 3-week Intervention Study

Abstract Background:Nutritional interventions in morbidly obese individuals that effectively reverse pro-inflammatory state and prevent obesity-associated medical complications are highly warranted. Our aim was to evaluate the effect of high- (HP) or low- (LP) protein diets on circulating immune-inflammatory biomarkers, includingC-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-a), interleukin-10 (IL-10), monocyte chemoattractant protein-1 (MCP-1),chemerin, omentin, leptin, total adiponectin, high molecular weight adiponectin and fetuin-A.Methods:18 people with morbid obesity were matched into two hypocaloric diet groups: HP (30E% protein, n=8) and LP (10E% protein, n=10) for three weeks.Biomarkers were measured pre-post intervention.We used linear mixed-effects models to investigate differences of least squares means for biomarkers, adjusted for age, sex, BMI, and baseline value.Results:Consuming HP or LP diets resulted in reduced CRP(HP: -2.2 ± 1.0 mg/l, LP: -2.3 ± 0.9 mg/l) and chemerin (HP: -17.9 ± 8.6 ng/ml, LP: -20.0 ± 7.4 ng/ml). People following the LP diet showed decreased leptin (-19.2± 6.0 ng/ml), IL-6 (-0.4 ± 0.1pg/ml) and increased total adiponectin (1.6 ± 0.6µg/ml). Changes were observed for remaining biomarkers yetto a smaller degree.Conclusions:These data suggest LP dietsmodulatea wider range of immune-inflammatory biomarkers compared to HP diets in morbidly obese individuals.Larger trials are needed to allow firm conclusions on the suggested effects.Trial registration: DRKS00009509. Registered 25 January 2016 – Retrospectively registered, www.drks.de