Effect of a Free-Living Ketogenic Diet on Feasibility, Satiety, Body Composition, and Metabolic Health in Women: The Grading Level of Optimal Carbohydrate for Women (GLOW) Study

J Am Coll Nutr. 2021 May-Jun;40(4):295-306. doi: 10.1080/07315724.2021.1875338. Epub 2021 Mar 11.

Abstract

Objective: The study's purpose was to examine a free-living, ketogenic diet (WFKD) on feasibility, satiety, body composition, and metabolic health in women.

Methods: Twenty-two women (age (yr.) 42.2 ± 8.1, Ht. (cm) 164.2 ± 5.9, BMI 27.3 ± 6.0) participated in a 21-day, free-living dietary intervention. Daily ketone measurements and satiety/craving surveys, weekly diet records, and PRE and POST assessments of anthropometrics, body composition, blood pressure, and fasted capillary-blood glucose (BG) and cholesterol panels were collected.

Results: Women maintained calories (PRE: 1938 kcal vs POST: 1836 kcal) and protein (PRE: 17% vs POST: 20%) but decreased carbohydrate (PRE: 36% vs POST: 13%) and increased fat (PRE: 45% vs POST: 65%) PRE to POST (p ≤ 0.05). Daily self-reports suggested no changes in satiety or food cravings between PRE, WK 1, WK 2, and WK 3. Ketones increased (PRE 0.3 ± 0.2 mmol vs POST 0.8 ± 0.6 mmol) PRE to POST with significant differences between PRE and all other time points (p ≤ 0.05). Bodyweight (PRE: 73.9 kg vs POST: 72.3 kg) and body fat (PRE: 28.9 ± 13.4 kg vs POST 27. 4 ± 13.5 kg) decreased but there were no differences in fat-free mass PRE to POST (p ≤ 0.05). Systolic blood pressure decreased (PRE: 119.2 ± 8.9 mmHg vs POST: 109.5 ± 10.9 mmHg), diastolic blood pressure increased (PRE: 74.1 ± 7.5 mmHg vs POST: 78.8 ± 7.4 mmHg), and BG improved (94.0 ± 8.3 mg/dL vs POST 89.9 ± 9.0 mg/dL) PRE to POST (p ≤ 0.05). No differences were observed in total cholesterol (TC), high-density lipoprotein (HDL), and triglycerides (TG) but TC/HDL decreased and low-density lipoprotein increased PRE to POST (p ≤ 0.05).

Conclusion: Women were able to maintain calories, improve body composition, blood pressure, and BG, increase ketones, and improve some but not all cholesterol markers after 21 days on a free-living WFKD.

Keywords: Ketogenic diet; body composition; metabolic health; nutritional ketosis; women’s health.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Body Composition
  • Diet, Ketogenic*
  • Dietary Carbohydrates
  • Feasibility Studies
  • Female
  • Humans
  • Triglycerides

Substances

  • Dietary Carbohydrates
  • Triglycerides