Published: 01/05/2022

What does the science say about the efficacy of low-carbohydrate diets (LCDs)?

Mounting evidence has demonstrated that restricting carbohydrate intake is associated with wide-ranging benefits.

  • Weight Loss: LCDs enable the body to preferentially metabolize fat for energy. Carbohydrates are the major stimuli for insulin release, which, in turn, inhibits fat breakdown, promotes fat storage, and complicates weight-loss efforts. Reducing carbohydrate intakes, and consequently insulin levels, results in a unique metabolic state—lipolysis and ketosis—enabling the body to increase fat oxidation for energy use and decrease fat synthesis (5-7), resulting in total body fat reduction and, thus, weight loss.
  • Chronic Disease Prevention and Management: Beyond weight loss, studies also show carbohydrate restriction results in global improvements in biomarkers related to metabolic syndrome, cardiovascular disease, and diabetes. Evidence consistently shows LCDs help reduce hemoglobin A1c and blood pressure, improve lipoprotein profiles, and increase resting and total energy expenditure values (8-12).

Importantly, evidence from multiple studies indicate that, for most people, restricting carbohydrates is also a more effective dietary intervention than restricting dietary fat (13-29). This is supported by a systematic review and meta-analysis concluding that low carbohydrate diets have favorable effects on weight loss, metabolic syndrome, and major cardiovascular risk factors (30).