Association of Low-Carbohydrate and Low-Fat Diets With Mortality Among US Adults
Authors: Qibin Qi
Frank B Hu
Liegang Liu
Zhilei Shan
Yanjun Guo
Journal: JAMA internal medicine (2020)
Discipline: CLINICAL MEDICINE
Keywords: carbohydrate; fat; mortality; low-carbohydrate diet; low-fat diet
Affiliations: Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, Massachusetts., Division of Preventive Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts., Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts., Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts., Department of Nutrition and Food Hygiene, Hubei Key Laboratory of Food Nutrition and Safety, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China., MOE Key Lab of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China., Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, New York.

Abstract:  Importance: It is crucial to incorporate quality and types of carbohydrate and fat when investigating the associations of low-fat and low-carbohydrate diets with mortality. Objective: To investigate the associations of low-carbohydrate and low-fat diets with total and cause-specific mortality among US adults. Design, setting, and participants: This prospective cohort study used data from the US National Health and Nutrition Examination Survey from 1999 to 2014 from 37 233 adults 20 years or older with 24-hour dietary recall data. Data were analyzed from July 5 to August 27, 2019. Exposures: Overall, unhealthy, and healthy low-carbohydrate-diet and low-fat-diet scores based on the percentage of energy as total and subtypes of carbohydrate, fat, and protein. Main outcomes and measures: All-cause mortality from baseline until December 31, 2015, linked to National Death Index mortality data. Results: A total of 37 233 US adults (mean [SD] age, 49.7 [18.3] years; 19 598 [52.6%] female) were included in the present analysis. During 297 768 person-years of follow-up, 4866 total deaths occurred. Overall low-carbohydrate-diet and low-fat-diet scores were not associated with total mortality. The multivariable-adjusted hazard ratios for total mortality per 20-percentile increase in dietary scores were 1.07 (95% CI, 1.02-1.11; P = .01 for trend) for unhealthy low-carbohydrate-diet score, 0.91 (95% CI, 0.87-0.95; P &lt; .001 for trend) for healthy low-carbohydrate-diet score, 1.06 (95% CI, 1.01-1.12; P = .04 for trend) for unhealthy low-fat-diet score, and 0.89 (95% CI, 0.85-0.93; P &lt; .001 for trend) for healthy low-fat-diet score. The associations remained similar in the stratification and sensitivity analyses. Conclusions and relevance: In this study, overall low-carbohydrate-diet and low-fat-diet scores were not associated with total mortality. Unhealthy low-carbohydrate-diet and low-fat-diet scores were associated with higher total mortality, whereas healthy low-carbohydrate-diet and low-fat-diet scores were associated with lower total mortality. These findings suggest that the associations of low-carbohydrate and low-fat diets with mortality may depend on the quality and food sources of macronutrients. 

Retracted: No

PubPeer comments:
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