Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Meta-Analysis
, 3 (9), e419-e428

Dietary Carbohydrate Intake and Mortality: A Prospective Cohort Study and Meta-Analysis

Affiliations
Meta-Analysis

Dietary Carbohydrate Intake and Mortality: A Prospective Cohort Study and Meta-Analysis

Sara B Seidelmann et al. Lancet Public Health.

Abstract

Background: Low carbohydrate diets, which restrict carbohydrate in favour of increased protein or fat intake, or both, are a popular weight-loss strategy. However, the long-term effect of carbohydrate restriction on mortality is controversial and could depend on whether dietary carbohydrate is replaced by plant-based or animal-based fat and protein. We aimed to investigate the association between carbohydrate intake and mortality.

Methods: We studied 15 428 adults aged 45-64 years, in four US communities, who completed a dietary questionnaire at enrolment in the Atherosclerosis Risk in Communities (ARIC) study (between 1987 and 1989), and who did not report extreme caloric intake (<600 kcal or >4200 kcal per day for men and <500 kcal or >3600 kcal per day for women). The primary outcome was all-cause mortality. We investigated the association between the percentage of energy from carbohydrate intake and all-cause mortality, accounting for possible non-linear relationships in this cohort. We further examined this association, combining ARIC data with data for carbohydrate intake reported from seven multinational prospective studies in a meta-analysis. Finally, we assessed whether the substitution of animal or plant sources of fat and protein for carbohydrate affected mortality.

Findings: During a median follow-up of 25 years there were 6283 deaths in the ARIC cohort, and there were 40 181 deaths across all cohort studies. In the ARIC cohort, after multivariable adjustment, there was a U-shaped association between the percentage of energy consumed from carbohydrate (mean 48·9%, SD 9·4) and mortality: a percentage of 50-55% energy from carbohydrate was associated with the lowest risk of mortality. In the meta-analysis of all cohorts (432 179 participants), both low carbohydrate consumption (<40%) and high carbohydrate consumption (>70%) conferred greater mortality risk than did moderate intake, which was consistent with a U-shaped association (pooled hazard ratio 1·20, 95% CI 1·09-1·32 for low carbohydrate consumption; 1·23, 1·11-1·36 for high carbohydrate consumption). However, results varied by the source of macronutrients: mortality increased when carbohydrates were exchanged for animal-derived fat or protein (1·18, 1·08-1·29) and mortality decreased when the substitutions were plant-based (0·82, 0·78-0·87).

Interpretation: Both high and low percentages of carbohydrate diets were associated with increased mortality, with minimal risk observed at 50-55% carbohydrate intake. Low carbohydrate dietary patterns favouring animal-derived protein and fat sources, from sources such as lamb, beef, pork, and chicken, were associated with higher mortality, whereas those that favoured plant-derived protein and fat intake, from sources such as vegetables, nuts, peanut butter, and whole-grain breads, were associated with lower mortality, suggesting that the source of food notably modifies the association between carbohydrate intake and mortality.

Funding: National Institutes of Health.

Conflict of interest statement

Declaration of interests

LMS receives grant funding from the California Walnut Commission and Dairy Management Inc, which was not used for this project.SC reports grants from the National Institutes of Health (NIH), and personal fees from Novartis and Zogenix, outside the submitted work. All other authors have no competing interests.

Figures

Figure 1:
Figure 1:. U-shaped association between percentage of energy from carbohydrate and all-cause mortality in the ARIC cohort
The reference level is 50% energy from carbohydrate. Results are adjusted for age, sex, race, ARIC test centre, total energy consumption, diabetes, cigarette smoking, physical activity, income level, and education. ARIC=Atherosclerosis Risk in Communities.
Figure 2:
Figure 2:. Carbohydrate intake and mortality risk across multiple cohort studies
Mean values of percentage of energy from carbohydrate (% carbohydrate) reported in previously studied cohorts from lowest to highest quantiles. Adjusted HRs are from analyses of low carbohydrate scores versus high carbohydrate scores (n=432179, all-cause deaths=40 181). Dotted lines indicate cutoffs for low carbohydrate (<40%) and high carbohydrate (>70%). (A) Low carbohydrate versus moderate carbohydrate (40–70%) reference group. (B) High carbohydrate versus moderate carbohydrate reference group. HR=hazard ratio. ARIC=Atherosclerosis Risk in Communities. NHS=Nurses Health Study. HPFS=Health Professionals Follow-up Study.
Figure 3:
Figure 3:. U-shaped association between percentage of energy from carbohydrate and all-cause mortality in the ARIC and PURE cohort studies
The reference level is 46·4% energy from carbohydrate. ARIC results are adjusted for age, sex, education, waist-to-hip ratio, smoking, physical activity, diabetes, ARIC test centre, and energy intake. PURE results are are adjusted for age, sex, education, waist-to-hip ratio, smoking, physical activity, diabetes, urban or rural location, centre, geographical regions, and energy intake. The mean percentage of energy from carbohydrate in ARIC is 49%, and from PURE it is 61%. ARIC=Atherosclerosis Risk in Communities. PURE=Prospective Urban Rural Epidemiology.

Comment in

Similar articles

See all similar articles

Cited by 34 PubMed Central articles

See all "Cited by" articles

References

    1. US Department of Health and Human Services, US Department of Agriculture. Dietary Guidelines for Americans 2015–2020; Eighth edition https://health.gov/dietaryguidelines/2015/guidelines/ (accessed Aug 7, 2018).
    1. Sacks FM, Lichtenstein AH, Wu JHY, et al. Dietary fats and cardiovascular disease: a presidential advisory from the American Heart Association. Circulation 2017; 136: e1–23. - PubMed
    1. WHO. Healthy diet fact sheet. September 14, 2015. http://www.who.int/mediacentre/factsheets/fs394/en/ (accessed Aug 7, 2018).
    1. Nordmann AJ, Nordmann A, Briel M, et al. Effects of low-carbohydrate vs low-fat diets on weight loss and cardiovascular risk factors: a meta-analysis of randomized controlled trials. Arch Intern Med 2006; 166: 285–93. - PubMed
    1. No authors listed. Summaries for patients. Comparing low-fat and low-carbohydrate diets. Ann Intern Med 2014; 161: 309–18. - PubMed

Publication types

Substances

Feedback