Consumption of monosodium glutamate in relation to incidence of overweight in Chinese adults: China Health and Nutrition Survey (CHNS)

• Published in: The American journal of clinical nutrition 2011-06, Vol.93 (6), p.1328-1336
• Main Authors: He, Ka, Du, Shufa, Xun, Pengcheng, Sharma, Sangita, Wang, Huijun, Zhai, Fengying, Popkin, Barry
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Adults; Aged; Asian people; Biological and medical sciences; Body mass; Body Mass Index; China - epidemiology; Diet; Diet Records; Diet Surveys; Exercise; Feeding. Feeding behavior; Female; Flavoring Agents - adverse effects; Fundamental and applied biological sciences. Psychology; Health; Humans; Incidence; Lifestyle; Lifestyles; Longitudinal Studies; Male; Middle Aged; Nutrition; Nutrition Surveys; Obesity; Overweight - epidemiology; Overweight - etiology; Proportional Hazards Models; Prospective Studies; Reference Values; Regression analysis; Salt; Sodium Glutamate - adverse effects; Surveys; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Young Adult
• ISSN: 0002-9165; 1938-3207
• DOI: 10.3945/ajcn.110.008870

Background: It has been hypothesized that monosodium glutamate (MSG), a flavor enhancer, is positively associated with weight gain, which influences energy balance through the disruption of the hypothalamic signaling cascade of leptin action.Objective: The objective was to examine the longitudinal association between MSG consumption and incidence of overweight.Design: Data were collected from the China Health and Nutrition Survey (CHNS), a prospective open-cohort, ongoing nationwide health and nutrition survey, consisting of 10,095 apparently healthy Chinese adults aged 18–65 y at entry from 1991 to 2006. Diet, including MSG and other condiments, was assessed with a weighed food inventory in combination with three 24-h recalls. Incident overweight was defined as a body mass index (BMI; in kg/m2) ≥ 25 or ≥23 based on World Health Organization recommendations for Asian populations. Multilevel mixed-effects models were constructed to estimate change in BMI, and Cox regression models with gamma shared frailty were used to determine the incidence of overweight.Results: The mean follow-up was 5.5 y. The cumulative mean (±SD) MSG intake of 2.2 ± 1.6 g/d was positively associated with BMI after adjustment for potential confounders and cluster effects at different levels (individual, household, and community). The adjusted hazard ratio of overweight was 1.33 (95% CI: 1.01, 1.75; P for trend < 0.01) for participants in the highest quintile of MSG intake compared with those in the lowest quintile after adjustment for age, physical activity, total energy intake, and other major lifestyle factors.Conclusions: MSG consumption was positively, longitudinally associated with overweight development among apparently healthy Chinese adults. Additional studies are needed to elucidate mechanisms of action and to establish causal inference.