What are the associations of types of low-carbohydrate and low-fat diets with mortality among US adults?
In this cohort study of 37 233 US adults 20 years or older, overall low-carbohydrate and low-fat diets were not associated with total mortality, but a healthy low-carbohydrate diet (lower amounts of low-quality carbohydrates and higher amounts of plant protein and unsaturated fat) and a healthy low-fat diet (lower amounts of saturated fat and higher amounts of high-quality carbohydrates and plant protein) were associated with lower total mortality.
The associations of low-carbohydrate and low-fat diets with mortality may depend on the quality and food sources of macronutrients.
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.
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.
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.
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 < .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 < .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.
Identify all potential conflicts of interest that might be relevant to your comment.
Conflicts of interest comprise financial interests, activities, and relationships within the past 3 years including but not limited to employment, affiliation, grants or funding, consultancies, honoraria or payment, speaker's bureaus, stock ownership or options, expert testimony, royalties, donation of medical equipment, or patents planned, pending, or issued.
Err on the side of full disclosure.
If you have no conflicts of interest, check "No potential conflicts of interest" in the box below. The information will be posted with your response.
Not all submitted comments are published. Please see our commenting policy for details.
Shan Z, Guo Y, Hu FB, Liu L, Qi Q. Association of Low-Carbohydrate and Low-Fat Diets With Mortality Among US Adults. JAMA Intern Med. Published online January 21, 2020. doi:10.1001/jamainternmed.2019.6980
Coronavirus Resource Center
Customize your JAMA Network experience by selecting one or more topics from the list below.
Create a personal account or sign in to: